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“Trojan horse” nanoshells offer hope for more effective #cancer #treatment

Combining #nanoshells – laser-activated drug-loaded particles – with white blood cells could carry chemotherapy agents into tumours to reduce side-effects

One of the difficulties of treating cancer is getting drugs into tumour cells. Chemotherapy agents tend to get pushed out rather than being drawn in, so dosage levels have to be high for the treatment to be effective. As the drugs are often toxic, this leads to nausea and other harmful side effects. Researchers at Rice University in Houston, Texas are working on a strategy that promises to use the immune system to send tiny hollow particles loaded with drugs deep into tumours where they can be activated with a laser, releasing their payload exactly where needed and nowhere else.

Gold nanoshell (orange and pale blue) loaded with lapatinib (yellow stars| in albumin (dark blue): the laser releases the drug

The technique uses gold nanoshells — spheres of glass about a tenth of the size of red blood cells, coated with a thin shell of gold. Invented at Rice in the 1990s by engineer, chemist and physicist Naomi Halas, they can be loaded on their exteriors with drug active ingredients then released into cells. The drugs remain attached to the gold surface until the shells are activated with light; a near-infrared laser, capable of harmlessly penetrating living tissue, which heats up the nanoshell causing its load to detach and get to work inside the cell.

Halas has been investigating nanoshells’ anticancer potential for 15 years, and in the current research, published in the Proceedings of the National Academy of Sciences(PNAS), she and Susan Clare, a breast cancer surgeon, and colleagues at Rice, Northwestern University in Illinois and the University of Copenhagen, are looking at drugs that are particularly difficult to administer— tyrosine kinase inhibitors — which target specific proteins found in several different types of cancer, including leukaemia and tumours of the lung, pancreas, kidney, stomach , liver and thyroid.

“All the tyrosine kinase inhibitors are notoriously insoluble in water,” said Amanda Goodman, lead author of the PNAS study. “As a drug class, they have poor bioavailability, which means that a relatively small proportion of the drug in each pill is actually killing cancer cells.”

The study involved using nanoshells to deliver cytotoxic dosages of two drugs — the tyrosine kinase inhibitor lapatinib and docotaxel — into cultured breast cancer cells and then activating the shells with a laser after they had been absorbed. The laser, even at low power, is capable of penetrating through to tumours several inches below the skin, and the study showed that no drug molecules were released until the nanoshells were activated, at which point the whole load was shed.

The study used nanoshell-drug conjugates, with the docotaxel attached to the gold with a DNA linker and the lapatanib trapped in a coating of albumin, a protein found in blood. The lead author of the PNAS paper, Amanda Goodman, looked at the effectiveness of different types of laser in activating the nanoshells. This study confirms the clinical applicability of the technique, but the next phase will involve getting the drugs into real tumours in animals rather than cultured cells, for which a different strategy will be needed.

Source: https://nano-magazine.com/news/2017/11/14/trojan-horse-nanoshells-offer-hope-for-more-effective-cancer-treatment/

 

Can #nanotechnology #heal #scar #tissue?

 

Think #scars last a lifetime? Think again. If you’ve ever had a nasty burn from hot water or a kettle, chances are you’ve come away with a scar.

These scars can last a lifetime and can be debilitating for victims of more severe burns.

But that might be about to change, thanks to a little thing (and I mean really little thing) called #nanotechnology.

How little, I hear you ask? Try on a scale where things are measured in #nanometres or billionths of a metre. To understand how small a #nanometre is, pluck a hair from your head. That hair is 100,000 nanometres across.

Dr Tristan Clemons, a #UWA researcher, does his work on this minute scale. And while working on the nanoscale is pushing our science and technology to its limits, it’s on this tiny new frontier that the solutions to scar tissue might be found.

“Nanotechnology is answering a lot of questions about phenomena, which, up until now, have been unexplained,” says Tristan.

“By understanding how things operate on the nanoscale, we’re discovering a whole new world of scientific possibilities.”

TINY PARTICLES—BIG POTENTIAL

So why do scientists need to work on the #nanoscale to help heal burn wounds?

While the human body has been healing from burns for thousands of years, the process could be improved. Anyone with a scar can tell you that.

In the first step of the #healing process, the #body covers the wound with new cells in a process called reseeding.

“In the second stage, the body uses collagen to lay down new #tissue and keep out infection. However, the body goes a little too far and expresses too much collagen. This leads to dense and fibrous scar tissue,” said Tristan.

It’s in the reseeding process that Tristan and his team hope to use nano-scaffolds to improve the #healing process. These #nano-scaffolds, which are tiny structures 100 times smaller than a human hair, allow us to better control cell growth in the first stage of wound healing.

“By better controlling the healing process, we can avoid the overexpression of collagen. This would prevent the formation of lasting scar tissue.”

GIVING OLD SCARS NEW LIFE

While this work could prove to be revolutionary for victims still recovering from recent burns, it doesn’t provide relief to people who already have scarring. Tristan’s focus is on these people with existing scar tissue.

“We’ve seen people survive with 60 – 70% total surface area burns to their body. There’s horrific scarring that accompanies that, and quality of life after survival of such a traumatic event is severely diminished because of that scar tissue,” said Tristan.

“We’re looking at ways we can modify scar tissue to be more like healthy tissue by using nanoparticles as delivery agents.”

With the research still in its infancy, a nanotechnology-based cure to scar tissue could be over 10 years away. But Tristan is hopeful that this is just the beginning of the possibilities.

“Because we’re working on something that is a fundamental problem of #fibroticDisease, the application beyond just burns is quite large.”

All this amazing work just goes to show even the tiniest stuff can have a huge impact for the future.

Sources: https://phys.org/news/2017-10-nanotechnology-scar-tissue.html#jCp

https://nano-magazine.com/news/2017/10/16/can-nanotechnology-heal-scar-tissue/?email=nJarmusz@kenes-exhibitions.com

 

‘World’s hottest’ chilli pepper grown using nanofeed

chilli-pepper-nanofeed-NanoIsrael

A plant grower from the UK has helped grow what is believed to be the world’s hottest chilli pepper, after “introducing nanofeed into the plant”.

Mike Smith from St Asaph has been growing the Dragon’s Breath chilli, which belongs to Nottinghamshire chilli farmer Neal Price.

It has a Scoville scale rating of 2.4 million units of heat, compared to 1.5 million of the current record holder.

The chilli will be exhibited at the Chelsea Flower Show this week.

Mr Smith, who has been growing plants for about eight years, said the chilli’s heat was “beyond” and has the potential to be used as an alternative to anaesthetic in third world countries.

Mr Smith was loaned the chilli plant by Mr Price about three months ago, who grew it using a new plant food developed with Nottingham Trent University.

He has not tasted the chilli as he said “it would not be a pleasant sensation,” but Mr Price has.

He said it had an “initial fruity flavour” and is then “extremely hot for about half an hour”.

Mr Smith suggested the chilli could be used an alternative to anaesthetic in third world countries – which do not have access to or the money for the drug – as the oil from it is capable of numbing the skin.

It could also be useful on people who are allergic to anaesthetic.

An application to Guinness World Records is currently awaiting confirmation that the chilli is the world’s hottest.

The current record is held by The PuckerButt Pepper Company in the US for its Smokin Ed’s Carolina Reaper, which rates at an average of 1,569,300 Scoville heat units.

 

 

Source: https://nano-magazine.com/news/2017/5/22/worlds-hottest-chilli-pepper-grown-using-nanofeed

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Researchers build liquid biopsy chip that detects metastatic cancer cells in blood

A chip developed by mechanical engineers at Worcester Polytechnic Institute (WPI) can trap and identify metastatic cancer cells in a small amount of blood drawn from a cancer patient. The breakthrough technology uses a simple mechanical method that has been shown to be more effective in trapping cancer cells than the microfluidic approach employed in many existing devices.

Cancers that spread from one organ to another can be difficult to treat, so it is best to catch them early. Since cancer cells spread through the bloodstream, a blood test that can capture and identify circulating tumor cells could be a life saver. A new technology developed at Worcester Polytechnic Institute (WPI) does just that.

 

The WPI device uses antibodies attached to an array of carbon nanotubes at the bottom of a tiny well. Cancer cells settle to the bottom of the well, where they selectively bind to the antibodies based on their surface markers (unlike other devices, the chip can also trap tiny structures called exosomes produced by cancers cells). This “liquid biopsy,” described in a recent issue of the journal Nanotechnology, could become the basis of a simple lab test that could quickly detect early signs of metastasis and help physicians select treatments targeted at the specific cancer cells identified.

Metastasis is the process by which a cancer can spread from one organ to other parts of the body, typically by entering the bloodstream. Different types of tumors show a preference for specific organs and tissues; circulating breast cancer cells, for example, are likely to take root in bones, lungs, and the brain. The prognosis for metastatic cancer (also called stage IV cancer) is generally poor, so a technique that could detect these circulating tumor cells before they have a chance to form new colonies of tumors at distant sites could greatly increase a patient’s survival odds.

“The focus on capturing circulating tumor cells is quite new,” said Balaji Panchapakesan, associate professor of mechanical engineering at WPI and director of the Small Systems Laboratory. “It is a very difficult challenge, not unlike looking for a needle in a haystack. There are billions of red blood cells, tens of thousands of white blood cells, and, perhaps, only a small number of tumor cells floating among them. We’ve shown how those cells can be captured with high precision.”

 

The device developed by Panchapakesan’s team includes an array of tiny elements, each about a tenth of an inch (3 millimeters) across. Each element has a well, at the bottom of which are antibodies attached to carbon nanotubes. Each well holds a specific antibody that will bind selectively to one type of cancer cell type, based on genetic markers on its surface. By seeding elements with an assortment of antibodies, the device could be set up to capture several different cancer cells types using a single blood sample. In the lab, the researchers were able to fill a total of 170 wells using just under 0.3 fluid ounces (0.85 milliliter) of blood. Even with that small sample, they captured between one and a thousand cells per device, with a capture efficiency of between 62 and 100 percent.

In a paper published in the journal Nanotechnology [“Static micro-array isolation, dynamic time series classification, capture and enumeration of spiked breast cancer cells in blood: the nanotube–CTC chip”], Panchapakesan’s team, which includes postdoctoral researcher Farhad Khosravi, the paper’s lead author, and researchers at the University of Louisville and Thomas Jefferson University, describe a study in which antibodies specific for two markers of metastatic breast cancer, EpCam and Her2, were attached to the carbon nanotubes in the chip. When a blood sample that had been “spiked” with cells expressing those markers was placed on the chip, the device was shown to reliably capture only the marked cells.

In addition to capturing tumor cells, Panchapakesan says the chip will also latch on to tiny structures called exosomes, which are produced by cancers cells and carry the same markers. “These highly elusive 3-nanometer structures are too small to be captured with other types of liquid biopsy devices, such as microfluidics, due to shear forces that can potentially destroy them,” he noted. “Our chip is currently the only device that can potentially capture circulating tumor cells and exosomes directly on the chip, which should increase its ability to detect metastasis. This can be important because emerging evidence suggests that tiny proteins excreted with exosomes can drive reactions that may become major barriers to effective cancer drug delivery and treatment.”

Panchapakesan said the chip developed by his team has additional advantages over other liquid biopsy devices, most of which use microfluidics to capture cancer cells. In addition to being able to capture circulating tumor cells far more efficiently than microfluidic chips (in which cells must latch onto anchored antibodies as they pass by in a stream of moving liquid), the WPI device is also highly effective in separating cancer cells from the other cells and material in the blood through differential settling.

“White blood cells, in particular, are a problem, because they are quite numerous in blood and they can be mistaken for cancer cells,” he said. “Our device uses what is called a passive leukocyte depletion strategy. Because of density differences, the cancer cells tend to settle to the bottom of the wells (and this only happens in a narrow window), where they encounter the antibodies. The remainder of the blood contents stays at the top of the wells and can simply be washed away.”

While the initial tests with the chip have focused on breast cancer, Panchapakesan says the device could be set up to detect a wide range of tumor types, and plans are already in the works for development of an advanced device as well as testing for other cancer types, including lung and pancreas cancer. He says he envisions a day when a device like his could be employed not only for regular follow ups for patients who have had cancer, but in routine cancer screening.

“Imagine going to the doctor for your yearly physical,” he said. “You have blood drawn and that one blood sample can be tested for a comprehensive array of cancer cell markers. Cancers would be caught at their earliest stage and other stages of development, and doctors would have the necessary protein or genetic information from these captured cells to customize your treatment based on the specific markers for your cancer. This would really be a way to put your health in your own hands.”

 

Sources: https://www.wpi.edu/news/…

https://nano-magazine.com/news/2016/12/15/researchers-build-liquid-biopsy-chip-that-detects-metastatic-cancer-cells-in-blood

 

Tumor-Shrinking Nanoparticle May Be The Cure For Cancer

Cancer

May 03, 2017 – RESEARCH

Researchers from Mayo Clinic have successfully developed a new type of cancer-fighting nanoparticle. It is used to shrink breast cancer tumors while, at the same time, preventing recurrence of the disease.

The study was published in the journal “Nature Nanotechnology.” The team conducted the experiment on mice and injected them with the nanoparticle.

In a press release, results showed that subjects who received the injection had a 70 to 80 percent reduction in tumor size. Moreover, the mice treated with the nanoparticles demonstrated a resistance to future tumor recurrence even when they were exposed to cancer cells a month later.

The newly-developed nanoparticle produced potent and tumor immune responses to HER2-positive breast cancers. Breast cancers with higher levels of this type of protein are known to be more aggressive and spread more quickly than those without the mutation.

Betty Y.S. Kim, M.D., Ph.D., principal investigator of the study, said that they were astonished to find that the mice injected with the nanoparticles showed “a lasting anti-cancer effect.” Kim is a neurosurgeon and neuroscientist who specializes in brain tumors at Mayo Clinic’s Florida campus.

The custom-designed nanomaterials actively engage the entire immune system to kill cancer cells, unlike current cancer immunotherapies that target only a portion of it. This prompts the body to create its own memory system to minimize tumor recurrence.

The nanoparticle has been named as “Multivalent Bi-specific Nano-Bioconjugate Engager.” It is coated with antibodies that target the HER2 receptor and it is coated with molecules that engage two facets of the body’s immune system.

Further success of this study can lead to nanomedicines which are expected to be expanded to target different types of cancer and other human diseases. This includes neurovascular and neurodegenerative disorders.

Nanotechnology has been found to destroy precancerous tumor cells in the livers of mice and in vitro human cells. The international study was led by the University of Missouri School of Medicine.

 

Source: https://nano-magazine.com/news/2017/5/3/tumor-shrinking-nanoparticle-may-be-the-cure-for-cancer

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Top 3 Nano technology

The new Nano technology: Ultra Ever dry Spray-on clothing and other surfaces Liquipel.

 

See more about the new Nano Technologies during our next edition of Nano Israel:

http://www.kenesexhibitions.com/nanoisrael2016

The evening of the awards at Nano Israel 2016

The Nano Israel 2016 Awards Ceremony celebrated the achievements of a number of outstanding contributors in the various Competitions: The Tenne Family Prize, including a grant from The Israel Chemical Society, and prizes donated by Camtek for the Best Poster at the Exhibition, Nano Art Competition and Company and Innovation of the year.

 

The 2015 Tenne Family Prize in memory of Lea Tenne for Nanoscale Sciences was awarded to BGU’s Prof. Taleb Mokari of the Department of Chemistry and the Ilse Katz Institute for Nanoscale Science and Technology for his discoveries of novel synthetic approaches to high quality semiconductor nano-crystals, hybrid nanoparticles and nanowires.

 

The Best Poster Award was presented in 3 sub-categories:

 

Betina Nano Israel 2016 Poster award

 

Tslil_Gabrieli_Nano_poster_2016

 

The Nano Art Awards were awarded by Prof. Oris Ivan (in the name of Ron Navaro and Ron Blonder from the Wise Institute) as follows:

 

Shoval_hila

 

Nir_Sivan_Nano_Art

 

Burrows_HadassahChandaluri_Chanchayya

 

The Company/Innovation of the year in Nanotechnology:

 

Nano Israel 2016 is the premier nanotechnology event in Israel bringing together local and international business communities, scientists and students. These professionals and their achievements are shaping the future of the Nano Science not only in Israel, but in the world itself.

 

מוסף ננו 2016 – קישור למהדורה דיגיטלית

 

שלום לכולם

 

אתמול הופץ מוסף ננו לקראת הכנס ננו 2016.

יש סיבה מיוחדת לשמחה וגאווה בנושא. הצלחנו, בעזרתכם הנדיבה,

להפיק מוסף מקצועי, מעניין ועישר בתכנים,וזאת למרות המציאות המסחרית

הלא קלה ותחרות בין המדיות השונות לקראת האירוע!

 

לפיכך, הייתה לנו מחויבות מקצועית ואטית לעמוד באתגר ולייצר מוצר ברמה הגבוהה.

ואני מאמין שעשינו זאת.   

 

שוב תודה, ונפגש במהדורה הבאה!

 

(להלן גרסה דיגיטלית של המוסף (ניתן לדפדף

 

http://www.haaretz.co.il/st/inter/Global/magazine/Haaretz/2015/Nano_Feb_2016/index.html

 

Nanotech_magazine NanoIsrael_2016_Nanotech

Grand opening of Nano Israel 2016 Conference & Exhibition

Today, 22 February 2016, the 5th International Nanotechnology Conference & Exhibition of Kenes Exhibitions opens its doors for visitors at Smolarz Auditorium in Tel Aviv University, Israel.

 

Join us for two days of conference and workshops to improve your knowledge of nano technologies, computing evolution and nanoscience. Learn more about nano medicine and nano energy achievments, about innovations and policy…

 

The event will unite national and international scientists and lectorers, national labs, as well as representatives from the major universities and industries.

 

Opening session will be given by prof. Joseph Klafter from Tel Aviv University and Mr. Avi Hasson, Ministry of Economy and Industry, Israel.

 

Should you wish for a place to meet with colleagues for potential business ventures,you are more than welcome to utilize the networking area if available.

 

There is an extensive poster exibition and art competition with numerours awards at the closing ceremony.

 

Conference details and information may be found here: Nano Israel 2016. The registration is on-site.

 

IMG-20160222-WA0007Nano_Israel_Conference20160222_0751041456122806538-17750574591456122948124-16454921581456124203596-1371031510Nano_Exhibition&ConferenceNano_IsraelNano_Israel_2016Nano_Israel_Conference1456123555308-1842541413Nanotechnology_ExhibitionProf.Joseph_Klafter_Tel_Aviv_University_IsraelMr.Avi_Hasson_Ministry_of_Economy_Industry_IsraelIMG-20160222-WA0006IMG-20160222-WA0018IMG-20160222-WA0019IMG-20160222-WA0020IMG-20160222-WA0021IMG-20160222-WA0025IMG-20160222-WA0022IMG-20160222-WA0023

Israeli development package that will make our food healthier

פיתוח ישראלי: אריזה שתהפוך המזון שלנו לבריא יותר
חוקרים בטכניון פיתחו את האריזה המבוססת על טכנולוגיית ננו – המבוססת על פלסטיק המכיל ננו-צינוריות ושמנים טבעיים, השומרת על המזון בתוכה ומונעת התפתחות עובש וחיידקים. האריזה תוצג בכנס ננו-ישראל 2016 – שייערך בתל אביב בפברואר
רות נווהפורסם: 26.01.16 , 15:46

פיתוח חדשני – אריזה שתגן על האוכל שלנו מלפתח עובש וחיידקים. זה הפיתוח שיוצג בכנס ננו-ישראל 2016 שייערך בחודש הבא בתל אביב על ידי מקס קרפקר ורותם שמש, דוקטורנטים במעבדתה של פרופ’ אסתי סגל מהפקולטה להנדסת ביוטכנולוגיה ומזון וממכון ראסל ברי לננו – טכנולוגיה בטכניון.

האריזה היא למעשה שקית פלסטיק רגילה למראה, שחלק מרכיביה הוא ננו-צינוריות זעירות המכילות שמנים אתריים, המבוססים על תמציות טבעיות של צמחים, כגון בזיליקום וטימין (קורנית). השמנים הללו ידועים מזה מאות שנים בפעילותם האנטי-מיקרוביאלית, כלומר ביכולתם לקטול חיידקים, עובש ופטריות.

האריזה משחררת את השמן הנדיף באופן מבוקר אל המאפים שבתוכה, וכך מונעת התפתחות של מיקרואורגניזמים הגורמים לקילקול המזון. כך אפשר להאריך בצורה בטוחה את חיי המדף של המוצר ולהפחית את השימוש בחומרים משמרים.

מקס קרפקר ורותם שמש מציגים את הפיתוח ( )
מקס קרפקר ורותם שמש מציגים את הפיתוח

כנס “ננו-ישראל 2016” הוא אירוע בינלאומי העוסק בחידושים ובהזדמנויות עסקיות בתחומי הננו-טכנולוגיה. בכנס ובתערוכה שתתקיים במסגרתו יוצגו כמה מההמצאות הבולטות שפותחו בישראל בתחומי החומרים, הרפואה, המובייל, התעופה והמוליכים למחצה ובתחומי תעשייה חדשניים נוספים.

בכנס ישתתפו נציגים מישראל ומחו”ל ובהם אנשי הון סיכון, קרנות פרטיות, משקיעים מוסדיים וארגוניים, אנשי תעשייה, טכנולוגיה ופיתוח, מקבלי החלטות בממשל וכן נציגי אקדמיה, מדענים וחוקרים.

“הפיתוח שלנו ישמור על איכות הסביבה”
“באמצעות שילוב בין מיקרוביולוגיה וטכנולוגיית ננו פיתחנו אריזה אנטי-מיקרוביאלית בעלת ערך ממשי לצרכנים ולתעשיית המזון,” אומרת רותם. “מרגש לדעת שהפיתוח שלנו, המבוסס על חומרי גלם זמינים וזולים דוגמת בזיליקום, טימין וגרניום יאפשר לכל משק בית בישראל לחסוך בעלויות ולשמור על איכות הסביבה”.

“לפיתוחים הנעשים באמצעות ננו-טכנולוגיה יש השפעה מרחיקת לכת על כל תחומי החיים,” אומר בוגר הטכניון רפי קוריאט, המכהן כיו”ר משותף לכנס ננו-ישראל 2016. “פיתוח טכנולוגיות ננו בתחום המזון מזמן אלינו שפע של פתרונות לבעיות שלא היינו יכולים לפתור בדרך אחרת.

“הכנסתן של ננוטכנולוגיות ויישומם של מחקרים אקדמיים בתעשיית המזון, כמו גם בתעשיות נוספות כגון תעשיות הטקסטיל, האנרגיה והרכב, יכולים לפתוח בפני היצרנים שפע של אפשרויות ויישומים חדשים ולשפר את יכולתם להתחרות בשווקים הבינלאומיים”.

הטכנולוגיה הייחודית פותחה במסגרת פרויקט מגנ”ט של משרד הכלכלה, תוך שיתוף פעולה הדוק בין הטכניון לחברות תעשייתיות מובילות ובהן חברת כרמל אולפינים. הפיתוח כבר נמצא בשלב מתקדם, והחוקרים באקדמיה ובתעשייה מעריכים שבקרוב יעלו על המדפים מוצרי מזון הארוזים בטכנולוגיה זו.
 

http://www.ynet.co.il/articles/0,7340,L-4758061,00.html

Nanotechnology: small particles – a great future

 
ננוטכנולוגיה: חלקיקים קטנים – עתיד גדול
 
בעולם מכנים אותו הגל הבא במהפכה התעשייתית ולמרות ההשקעה הדלה יחסית מצד המדינה – ישראל היא בין המדינות המובילות במחקר ופיתוח בתחום הננוטכנולוגיה. לקראת כנס בינלאומי בתחום שיתקיים בישראל בשבוע הבא, ביקרנו במרכז לננוטכנולוגיה של בר אילן. יש למה לצפות

בישראל הונחה התשתית בתחילת שנות האלפיים, כאשר בששת המוסדות האקדמים המובילים הוקמו מרכזים לחקר ופיתוח ננוטכנולוגיה. אחד מהם הוא המכון של אוניברסיטת בר אילן שבו ביקרנו. המכון הוקם בשנת 2007 ומאז כבר מכיל 58 מעבדות ועוד 15 מעבדות ציוד מתקדם וכ-500 אנשי צוות.

 לאן מועדות פנינו?
עד כה נשמע שנפתרו כל בעיות העולם, אין יותר מחלות גנטיות חשוכות מרפא או כתמים על הג’ינס – אך התמונה פחות ורודה. בדירוגים העולמיים של פטנטים בתחום הננוטכנולוגיה, קשה למצוא את ישראל מבין המדינות המובילות. למרות נקודת הפתיחה המאוחרת יחסית לעולם, ישראל הצליחה להניח תשתית טובה, הוקמו מרכזי המחקר והפיתוח לננוטכנולוגיה וב-2005 הוקם המיזם הלאומי לננוטכנולוגיה (INNI). אולם מנתונים של השנים האחרונות ההשקעה של המדינה בתחום היא גם בננו אחוזים. לעומת המדינות המובילות בעולם, כמו ארצות הברית, יפן וגרמניה שמשקיעות מיליארדי דולרים בשנה – בישראל הוקצו רק כ-50 מיליון דולרים בשנה האחרונה.
 
על פי דו״ח של INNI, מאז יצאה לדרך התוכנית לקידום תחום הננוטכנולוגיה לפני כעשור, הושקעו בענף כ-400 מיליון דולר ממקורות ממשלתיים ומתקציבי האוניברסיטאות (חשוב להדגיש שזהו תקציב של עשור) הוקמו ששת מרכזי ננוטכנולוגיה באקדמיה, שמקיימים ביניהם שיתוף פעולה ועם התעשיה הישראלית, כ-140 מדענים בכירים בתחומי הננו-טכנולוגיה חזרו לישראל, נרשמו כ- 600 פטנטים, שמהם יושמו כמחצית והוקמו כ-130 חברות חדשות.

במהלך התוכנית אף הוכשרו כ-1000 בעלי תואר שלישי וכ-1800 בעלי תואר שני, מהנדסים ומדענים, שיהוו את התשתית האנושית להמשך הפיתוח באקדמיה וליישום אותם פיתוחים בתעשייה, אבל המחסור במומחים בתחום מורגש. הסיבות לכך: מספר בוגרי התיכון בעלי כישורים מתמטיים מספיקים שעומד על כ-6000 בשנה, מספר בוגרי המקצועות הטכנולוגיים באוניברסיטאות ובמכללות שעומד על כ-4,500 בשנה והבעיה המוכרת ביותר – בריחת המוחות.

מתוך כך מסביר רפי קוריאט, שותף במיזם הננו-טכנולוגיה הלאומי הישראלי ומבכירי התעשייה, כמה חשובה ההשקעה בתחום: “אני צופה שתוך פחות מעשור לא יהיה ולו

תחום אחד שלא יכלול בתוכו בצורה זאת או אחרת את הננוטכנולוגיה ונכון עשתה מדינת ישראל שחזתה את העתיד והקדישה לכך את התמיכה הראויה. אני מקווה שמקבלי ההחלטות מבינים שישראל יכולה להיות אחת מהחשובות בתחום בעולם וימצאו את הדרך לחזק את התשתית וההישגים שצברנו עד כה”.

הכנס ייערך בין 22-23 בפברואר 2016, באודיטוריום סמולארש, באוניברסיטת תל אביב.
להרשמה לכנס NanoIsrael 2016 דרך האתר

 
 Nano_Israel_article

http://www.ynet.co.il/articles/0,7340,L-4765977,00.html

 

Venue & Exhibition Map

Map Univeritys Nano Israel

MAP NANO UNIVERSITY-page-001MAP NANO UNIVERSITY-page-002

DONITZA PR NANO ISRAEL 2016

Published on Feb 8, 2016 GLOBES-DONITZA-NANO2016

לקראת כנס הננו 2016 – אייטם שארגנו בערוץ 2 – בתוכנית הבוקר של אברי גלעד והלה קורח: חוקרים בטכניון פיתחו אריזה מבוססת טכנולוגיית ננו שתאריך את חיי המדף של מוצרי מאפה
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בכנס ננו-ישראל 2016 יציגו חוקרים מהטכניון פיתח חדשני: אריזה למזון – ובעיקר מאפים – המבוססת על פלסטיק המכיל ננו-צינוריות ושמנים טבעיים, השומרת על המאפים המאוחסנים בתוכה ומונעת התפתחות עובש וחיידקים
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דו״ח של האו״ם הראה כי כ-30% מהמזון שמיוצר היום בעולם נזרק לפח מבלי שנפתח ונאכל. מקס קרפקר ורותם שמש, דוקטורנטים במעבדתה של פרופ’ אסתי סגל מהפקולטה להנדסת ביוטכנולוגיה ומזון וממכון ראסל ברי לננו – טכנולוגיה בטכניון, מציעים כעת פתרון לבעיה שיכולה לחסוך כסף רב לצרכנים: אריזת פלסטיק ייחודית המכילה שמנים אתריים טבעיים ומגנה על לחם, גבינות ומזונות אחרים מפני עובש וחיידקים. הפיתוח החדשני יוצג בכנס ננו-ישראל 2016, שייערך בתאריכים 23-22 בפברואר באוניברסיטת תל אביב.

האריזה היא למעשה שקית פלסטיק רגילה למראה, שחלק מרכיביה הוא ננו-צינוריות זעירות המכילות שמנים אתריים, המבוססים על תמציות טבעיות של צמחים, כגון בזיליקום וטימין (קורנית). השמנים הללו ידועים מזה מאות שנים בפעילותם האנטי-מיקרוביאלית, כלומר ביכולתם לקטול חיידקים, עובש ופטריות. האריזה משחררת את השמן הנדיף באופן מבוקר אל המאפים שבתוכה, וכך מונעת התפתחות של מיקרואורגניזמים הגורמים לקילקול המזון. כך אפשר להאריך בצורה בטוחה את חיי המדף של המוצר ולהפחית את השימוש בחומרים משמרים. הטכנולוגיה הייחודית פותחה במסגרת פרויקט מגנ”ט של משרד הכלכלה, תוך שיתוף פעולה הדוק בין הטכניון לחברות תעשייתיות מובילות ובהן חברת כרמל אולפינים. הפיתוח כבר נמצא בשלב מתקדם, והחוקרים באקדמיה ובתעשייה מעריכים שבקרוב יעלו על המדפים מוצרי מזון הארוזים בטכנולוגיה זו.
“באמצעות שילוב בין מיקרוביולוגיה וטכנולוגיית ננו פיתחנו אריזה אנטי-מיקרוביאלית בעלת ערך ממשי לצרכנים ולתעשיית המזון,” אומרת רותם. “מרגש לדעת שהפיתוח שלנו, המבוסס על חומרי גלם זמינים וזולים דוגמת בזיליקום, טימין וגרניום יאפשר לכל משק בית בישראל לחסוך בעלויות ולשמור על איכות הסביבה.”

על כנס הננו
כנס “ננו-ישראל 2016” הוא אירוע בינלאומי העוסק בחידושים ובהזדמנויות עסקיות בתחומי הננו-טכנולוגיה. בכנס ובתערוכה שתתקיים במסגרתו יוצגו כמה מההמצאות הבולטות שפותחו בישראל בתחומי החומרים, הרפואה, המובייל, התעופה והמוליכים למחצה ובתחומי תעשייה חדשניים נוספים. בכנס ישתתפו נציגים מישראל ומחו”ל ובהם אנשי הון סיכון, קרנות פרטיות, משקיעים מוסדיים וארגוניים, אנשי תעשייה, טכנולוגיה ופיתוח, מקבלי החלטות בממשל וכן נציגי אקדמיה, מדענים וחוקרים. יחסי ציבור לכנס: דוניצה תקשורת DONITZA PR

NANO TECHNOLOGIA DONITZA PR

Published on Jan 31, 2016

פרופ׳ עודד שוסיוב, מבכירי חוקרי הננו-טכנולוגיה בישראל, התארח באולפן ערוץ 10 ובשיחה עם פרופ׳ רפי קרסו מסביר מה זו ״ננו-טכנולוגיה״, מה ניתן לעשות איתה וחושף מספר פיתוחים מהמעבדה האישית שלו. המפגש נערך לקראת כנס הננו השנתי שייערך בתל אביב.

כנס הננו-טכנולוגיה הבינלאומי 2016
22-23 בפברואר 2016,
אודיטוריום סמולארש, אוניברסיטת תל אביב, ת״א

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מעל 1200 משתתפים מעשרות מדינות, יגיעו לתל אביב, בפברואר 2016, לקחת חלק בכנס “ננו-ישראל 2016” והתערוכה הנלויית אליו, להתרשם מהטכנולוגיות היותר מתקדמות בתחום, לבחון הישגים מדעיים ולשקול אפשרויות השקעה
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כנס “ננו-ישראל 2016” והתערוכה הנלויית אליו, ייערך בפברואר 2016, זו הפעם החמישית. הכנס הוא אירוע בינלאומי העוסק בחידושים ובהזדמנויות העסקיות החומרים, רפואה, מובייל, תעופה, מוליכים למחצה ותחומי תעשייה חדשניים נוספים. בין המשתתפים מהארץ ומהעולם, ניתן יהיה למצוא במפגש אנשי הון סיכון, קרנות פרטיות, משקיעים מוסדיים וארגוניים, אנשי רגולציה, טכנולוגיה ופיתוח, מקבלי החלטות בממשל, כמו גם גורמי אקדמיה, מדענים וחוקרים.

כנס “ננו-ישראל” הקודם, שנערך בשנת 2014, משך אליו 1000 נציגים מישראל ומהעולם. הכנס הקרוב ייערך בין 22-23 בפברואר 2016, באודיטוריום סמולארש, באוניברסיטת תל אביב, ועל פי ההערכות יגיעו אליו מעל 1200 משתתפים מעשרות מדינות.

ישראל נודעת בשל הישגיה וחדשנותה בתחום הננו. לאורך העשור האחרון ישראל מיצבה עצמה כמובילה ננו-טכנולוגית, המספקת אפשרויות חדשות ומרגשות בתחומי הרפואה, מובייל, ביטחון ועוד תחומים מתעשיית ההיי-טק. בכנס ובתערוכה הנלויית, ניתן יהיה להתרשם מההישגים המדעיים ולשקול אפשרויות השקעה.

מעל 40 חברות ננו ישראליות יציגו את חידושיהן, מאות סטודנטים מרחבי הארץ יציגו את עבודותיהם ב״פוסטרים״ וגם השנה תיערך תחרות “אמנות ננו”, שבסופה יוצגו בתערוכה עבודות אמנות המבוססות על ננו-טכנולוגיה. בביתן מיוחד של מתימו”פ – מרכז התעשיה הישראלית למחקר ופיתוח, ובשיתוף המדען הראשי, אף יוצגו כמה מהיישומים היותר מתקדמים של התחום.

“ננו-ישראל 2016” נערך בארגון חברת “כנס תערוכות” בשיתוף INNI – מיזם הננו-טכנולוגיה הלאומי הישראלי, מרכזי הננו-טכנולוגיה באוניברסיטאות השונות, משרד הכלכלה, המדען הראשי, המנהלת הישראלית למו״פ האירופאיֿ ו-IATI. יור״ים הכנס הם פרופ’ אורי צ׳שנובסקי, מאוניברסיטת תל אביב, מבכירי חוקרי הננו-טכנולוגיה בישראל, וחתן פרס וייצמן למדעים; פרופ׳ יעל חנין, ראש המרכז לננו-מדע וננו-טכנולוגיה באוניברסיטת תל אביב, פיזיקאית המתמקדת בפיתוח ננו-התקנים אלקטרוניים ורפי קוריאט, שותף במיזם הננו-טכנולוגיה הלאומי הישראלי ומבכירי התעשייה.
יחסי ציבור: דוניצה תקשורת Donitza PR

Nano art features nanolandscapes

Nano art features nanolandscapes (molecular and atomic landscapes which are natural structures of matter at molecular and atomic scales) and nanosculptures (structures created by manipulating matter at molecular and atomic scales using chemical and physical processes). These structures are visualized with research tools like scanning electron microscopes and atomic force microscopes and their scientific images are captured and may be further processed by using different artistic techniques to convert them into artworks showcased for large audiences.

art features nanolandscapes Nano_technologiesNano_structures nanosculptures Nano Israel Post Nano-Israel

Venue

 

This year,  NanoIsrael 2016, the fifth bi-annual conference & exhibition, will be held on 22-23 February, 2016 at the Smolarz Auditorium, Tel Aviv University.

 

How to get there:

 

Map of the Campus

 

 

From North Ayalon:

Exit Rokach Boulevard interchange towards Tel Aviv University,

Turn left at the first circle,

Take the first turn right down to Dr. George Wise Street,

The auditorium is located at Gate four.

From South Ayalon:

Exit towards the direction of Sderot Rokach Interchange,

Turn left at the traffic light and immediately right in the direction of the University,

Drive to the first circle and turn left,

Turn Right at the first entrance down to Dr. George Wise street.

Through Namir:

From the North: Turn left to Boulevard Einstein,

Turn right into Haim Levanon Street,

Turn left into Dr. George Wise Street.

From the South: Turn right to Haim Levanon Street,

Turn right at the second light into Dr. George Wise Street,

The auditorium is located at Gate four.

Pedestrian entrance through gate 4 is adjacent to the north side of the Auditorium.

 

Public Transportation:

אגד, דן, רכבת ישראל, מטרופולין

Accommodation & Travel

Book your hotel reservation now!!! You will find a variety of hotels in order to suit your needs and desires..

 

Please contact Anna Farfanyuk directly via email:  afarfanyuk@kenes-exhibitions.com to obtain the best and lowest accommodation rates for your group requiring 10 or more rooms.

CONTACT FOR QUESTIONS/FURTHER INFORMATION                                                

Should you have any questions or require information with regard to registration and or accommodation please contact us directly:

Registration & Accommodation Department
3 Ariel Sharon Ave., Or Yehuda 6037606, Israel
Tel:  +972 (0) 74 745 7487
Fax: +972 (0) 74 745 7487
Email: afarfanyuk@kenes-exhibitions.com

Cancellation Policy
All changes or cancellations should be made in writing to: afarfanyuk@kenes-exhibitions.com
Please do not contact the hotel directly.
Cancellations/changes received between 45 to 30 days prior to arrival – full refund less USD $35 handling fee.
Cancellations/changes received between 29 to 14 days prior to arrival – 1 night cancellation charge.
Cancellations/changes received less than 13 days prior to arrival – no refund.
In the event of non- arrival the hotel will automatically release the reservation and payment will be non-refundable. 
 

Instructions for Poster Board and Digital Poster Preparation

Please note that your Poster Board will be displayed in two formats:

 

Please find below preparation instructions for both formats, note that it is mandatory to prepare both displays.

 

IMPORTANT NOTES FOR POSTER PRESENTATION

 

  1. Posters will be displayed in two formats (Poster Board and E-Poster Digital Display) on both days of the Conference. Poster presenters are requested to be present at their designated poster board(s) during breaks and poster sessions to answer questions.
  2. Poster Presenters are requested to provide one Power Point slide that will advertise their poster and will be presented on a slide show throughout the conference. (E-Poster Digital Display)
  3. The authors of accepted abstract submissions will be required to prepare their Poster in both formats according to the instructions below:

 

REGULAR POSTER BOARD PREPARATION INSTRUCTIONS:

 

In order to efficiently communicate the results of your research to the viewers, you are kindly requested to devote considerable effort in the design of your poster.  Please pay attention to details by carefully following the instructions outlined below:

Sample of Poster:

  
EQUIPMENT FOR POSTER DISPLAY

 

CONTENT      

 

LAYOUT

 

FONT

 

AND FINALLY

 

 

 E-POSTER DIGITAL DISPLAY PREPARATION INSTRUCTIONS:

 

To download the full instructions:

click button

 

 

Instructions for Oral Presentations

Speaker Presentations

 

All Speakers giving an oral presentation are kindly requested to bring their presentations with them to the designated Hall where they will speak. Presentations should be handed over to the assigned Technical Manager at the designated Hall at least one hour before the start of their session.

 

If using a PowerPoint (or any other Software) presentation, please note that you are requested to bring it on a CD, a DVD or on a Memory Stick/Disc-on-Key (using the USB port in the computer) for uploading.

If combining video or audio files with PowerPoint, please inform the Technical Manager at the designated Hall to ensure that all necessary files are saved in the appropriate folder. In addition, make sure to check it in the session hall where your lecture is taking place during a coffee or lunch break prior to your session, at least 30 minutes before the start of the session.

 

All speakers are welcome to place their belongings in room number 100 located on on the right side of Hall A, which is on the 1st Floor of the Smolarz Auditorium, Tel Aviv University.

 

IMPORTANT NOTE FOR MACINTOSH USERS

In order to use MAC presentations on a PC compatible computer please note that you need to prepare it according to the instructions below, before bringing it to the designated Hall: 

  1. Use a common font, such as Arial, Times New Roman, Verdana etc. (special fonts might be changed to a default font on a PowerPoint based PC). 
  2. Insert pictures as JPG files (and not TIF, PNG or PICT – these images will not be visible on a PowerPoint based PC). 
  3. Use a common movie format, such as AVI, MPG and WMV (MOV files from QuickTime will not be visible on a PowerPoint based PC).

 

You may use your own Macintosh laptop computer, however you are required to bring with you a VGA dongle/adapter compatible with your MAC for external video signal and come to check it first in your designated Hall as soon as you arrive and later on in the session hall where your lecture is taking place during the coffee or lunch break prior to your session, at least 1 hour before the start of the session.
IMPORTANT NOTE: Please advise the Conference Organizers ahead of time if you will be using your Macintosh laptop computer.

Nano-Optics

[12] WATER-WALLED MICROFLUIDICS

 

Shai Maayani1

 

 

1 Technion; Technion

 

 

 

Water-Walled Microfluidics

Liquids serve microcavity research ever since Ashkin’s studies on optical resonances in levitating droplets to recent optofluidic resonators. Droplets can provide optical quality factor (Q) in proximity to the limit restricted by water absorption and radiation loss. However, water micro-drops vaporize quickly due to their large area/volume ratio. Here we fabricate a water-air interface that almost entirely surrounds our device, allowing for >1,000,000 recirculations of light (finesse). We sustain the droplets for >16 hours using a nano-water-bridge that extends from the droplet to a practically-unlimited distant-reservoir that compensates for evaporation. Our device exhibits surface tension 8000-times stronger than gravity that self-stabilizes its shape to a degree sufficient to maintain critical coupling  as well as to resolve split modes. Our device has 98% of their surrounding walls made strictly of water-air interfaces with concave, convex or saddle geometries, suggesting an arbitrary-shape microfluidic technology with water-walls almost all-over.

 

 

 

[13] CAVITY OPTOCAPILLARY WITH WATER-WALLED RESONATORS

 

Shai Maayani1

 

 

1 Technion; Technion

 

 

 

Cavity Optocapillary with Water-Walled Resonators

Droplets, particularly water, are abundant in nature and artificial systems. If only we could monitor droplet interfaces at sub-nanometer resolution, we could see that it behaves like a stormy sea. This phenomenon has widely been studied since 1908 and is of key importance in surface science. Here we use the optical mode of a mdroplet to probe its radius fluctuation. Doing so, we record Brownian droplet-vibrations at 100-kHz rates and 1 0.006 ångström amplitude, in agreement with natural-frequency calculation and equipartition theorem. A fall in the fluctuation spectrum is measured below cutoff at the drop’s lowest eigenfrequency. Our resonantly-enhanced measurement technique may impact the study of thermal-capillaries in droplets which are significant to coalescence and rupture processes, particularly with the most-common and important liquid – water.

 

 

 

 

[15] DROPLET’S ACOUSTICS

 

tal carmon1, leopoldo martin1, raphael dahan1

 

 

1 Technion; Technion

 

 

 

Droplets represent a basic liquid structure that is contained by interfacial tension while bounded almost completely by free surfaces. Such droplets can host three types of resonances: optical-, capillary- and acoustical-ones. Contrary to their capillary resonances (Rayleigh, 1879) and to optical resonances (Ashkin, 1977), droplets’ acoustical resonances were rarely considered. The challenge lies in the fact that mdroplets’ acoustics requires modulating forces at MHz rates. Here we rely on optical forces (that can act sufficiently quickly) to experimentally excite acoustical resonances at 37 MHz that starts vibrating at an optical threshold of 68 mW. The optical modes that we are using as a mechanical exciter are circulating in the 40 mm drop with a 10 quality-factor. Our results open an experimental access to the acoustical resonances of droplets, which were rarely considered, neither theoretically nor experimentally.

 

 

 

[47] STIMULATED EMISSION (STED) PULSED MICROSCOPE WITH SUPERCONTINUUM LASER SOURCE.

 

Eugene Brozgol1

 

 

1 Bar Ilan; Bar Ilan

 

 

 

Stimulated Emission (STED) pulsed microscope with supercontinuum laser source.

Eugene Brozgol, Liat Altman, Yuval Garini

 

Abstract

Many biological structures have important characteristics at the nanometer scale. Due to the limitations of electronic and optical microscopy, these structures are poorly understood.

In our present work we focus on building a Stimulated Emission Depletion (STED) microscope, based on a pulsed, super continuum laser source.  Such a setup has unique characteristics, and will be utilized for studying the fine details of the telomere’s structure in eukaryotic nuclei. A telomere is a region of repetitive nucleotide sequences at each end of a chromatid, which protects the end of the chromosome from deterioration or from fusion with neighboring chromosomes. This study is interesting because telomere dysfunction is linked to genomic instability and tumorigenesis

Here we present the basics of the pulsed, continuum laser STED setup.

 

 

 

[49] MOLECULAR VIBRATION POLARITONS IN LOW-LOSS DIELECTRIC MICROCAVITIES IN THE MID-INFRARED

 

Merav Muallem1, Alex Palatnik1, Daniel Nessim1, Yaakov Tischler1

 

 

1 Bar-Ilan Institute of Nanotechnology and Advanced Materials; Bar-Ilan University

 

 

 

Microcavity devices exhibiting strong light-matter coupling in the mid-infrared spectral range offer the potential to explore exciting open physical questions pertaining to energy transfer between heat and light and can lead to a new generation of efficient wavelength tunable mid-infrared sources of coherent light based on polariton Bose-Einstein Condensation. Vibrational transitions of organic molecules, which often have strong absorption peaks in the infrared and considerably narrower linewidths than organic excitonic resonances, can generate polaritonic states in the mid-infrared spectral range using microcavity devices.

Here, narrow linewidth polaritonic resonances are exhibited in the mid-infrared by coupling the carbonyl stretch vibrational transition of a polymethyl methacrylate (PMMA) film to the photonic resonance of a low optical-loss mid-infrared microcavity, which consisted of two Ge/ZnS dielectric Bragg reflectors. Rabi-splitting of 14.3 meV is observed, with a 4.4 meV polariton linewidth at anti-crossing. The large Rabi-splitting relative to linewidth indicates efficient impedance-matching between the bare vibrational and photonic states.

Furthermore, polariton states from coupling a mixture of two vibration modes to the microcavity resonance are revealed using organic film composed from solid PMMA and liquid dimethylformamide (DMF). The solid and liquid components, both possess spectrally narrow carbonyl stretch peaks, resulting in three branches in the polariton dispersion relation. The upper branch (UB) is composed largely of the PMMA phonon and photon. The middle branch (MB) contains all three components, and the lower branch (LB) is mostly the DMF phonon mixed with the photon. Rabi splitting of 9.6 meV and 5.2 meV is found between the UB and the MB, and between the MB and LB, respectively. The sum of the Rabi splitting values, 14.8 meV, is similar to that of the PMMA cavity splitting.

Molecular-vibration polaritons incorporated in dielectric microcavities can be an enabling step towards realizing polariton optical switching, polariton condensation, and new hybrid coupled states of light and matter in both solid and liquid form, in the mid-infrared spectral range.

 

 

 

[57] INKJET PRINTING OF FLUORESCENT SEEDED NANORODS

 

Shira Halivni1

 

 

1 Hebrew University of Jerusale; Physical Chemistry

 

 

 

Inkjet Printing of Fluorescent Seeded Nanorods

 

Shira Halivni, Shay Shemesh, Nir Waiskopf, Yelena Vinetsky, Shlomo Magdassi and Uri Banin

 

Institute of Chemistry and the Center for Nanoscience and Nanotechnology, the Hebrew University of Jerusalem, Jerusalem, 91904, Israel.

The use of fluorescent semiconductor nanocrystals for ink-jet printing applications is gaining momentum in the last few years. Their unique optical features that are characterized by wide absorption spectrum accompanied by a tunable, sharp and narrow emission spectrum, along with their optical and chemical stability, offer interesting advantages for their implementation in various technologies.

Although the use of fluorescent spherical semiconductor nanocrystals (quantum dots) is previously reported, there are no reports for the use of fluorescent nanorods (quantum rods) in ink applications, and especially in ink-jet inks. Fluorescent nanorods are outstanding candidates for fluorescent inks, due to their relatively low particle-particle interactions and self-absorption, the robust synthesis of mono-dispersed nanocrystals, their high quantum yields and their intrinsic emission polarization properties. We report here on the development of new ink formulations containing seeded semiconductor nanorods, which have unique and improved properties compared to the quantum dots. The inks demonstrate highly efficient method for maintaining the optical stability of fluorescent NPs in printing, by replacing the commonly used quantum dots. The advantages of seeded nanorods over quantum dots in inks were examined by comparing the optical properties of both solutions and patterns prepared with the two structures by ink-jet printing and low reabsorption and low interactions were demonstrated by negligible emission shifts upon printing, and maintaining the high fluorescence quantum yield, unlike quantum dots which display quenching effects.

 

 

 

 

[77] EXPERIMENTAL SYSTEM OF THE FULL SCATTERING PROFILE OF CIRCULAR PHANTOMS

 

Idit Feder1, Hamootal  Duadi2, Dror Fixler2

 

 

1 Bar-Ilan University; Institute of Nanotechnology and Advanced Materials

 

 

2 Bar Ilan University; Institute of Nanotechnology and Advanced Materials

 

 

 

Experimental system of the full scattering profile of circular phantoms

 

Idit Feder, Hamootal Duadi, Rinat Ankri and Dror Fixler

Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Israel

 

Abstract

Human tissue is one of the most complex optical media since it is turbid and nonhomogeneous. We suggest a new optical method for sensing physiological tissue state, based on the collection of the ejected light at all exit angles, to receive the full scattering profile. We simulate the light propagation in homogenous and heterogeneous cylindrical tissues and obtain the full scattering profile. In addition we built a unique set-up for noninvasive encircled measurement. We use a laser, a photodetector and tissues-like phantoms presenting different diameters and different reduced scattering coefficients. Our method reveals an isobaric point, which is independent of the optical properties and linearly depends on the exact tissue geometry. Furthermore, while adding nanoparticles to the tissue our new method can detect it due to the change they cause in the reduced scattering coefficient. In our previous work, nanoparticles have been defined as contrast agents for diagnostics and treatment of different physiological conditions, such as cancer and atherosclerosis. In addition, the blood vessels in human tissues are the main cause of light absorbing and also scattering. Therefore, the effect of blood vessels on light-tissue interactions is essential for biomedical applications based on optically sensing, such as oxygen saturation, blood perfusion and blood pressure. We show the vessel diameter influence on the full scattering profile, and found higher reflection intensity for larger vessel diameters accordance to the shielding effect. These findings can be useful for biomedical applications such as non-invasive and simple diagnostic of the fingertip joint, ear lobe and pinched tissues.

 

 

 

[91] MATERIAL DETECTION IN PHYSIOLOGICAL SUBSTANCES BY A NOVEL NONINVASIVE OPTICAL TECHNIQUE

 

Inbar Yariv1, Hamootal  Duadi1, Anat Lipovsky1, Dror Fixler1, Rachel Lubart2

 

 

1 Bar Ilan University; Institute of Nanotechnology and Advanced Materials

 

 

2 Bar Ilan University; Bar Ilan University

 

 

 

Physiological substances pose a challenge for researchers since their optical properties change constantly according to their physiological state. Examination of those substances noninvasively can be achieved by different optical methods with high sensitivity.

Our research suggests a novel noninvasive optical technique for the detection of materials in physiological substances. The optical technique is based on extracting the optical properties of substances, and especially the reduced scattering coefficient (µs‘). By examining the changes of the substance optical properties, detection of materials within it can be possible. The suggested optical technique, which examines the light reflection from and transmission through substances as shown in Figure 1, is based on iterative Gerchberg-Saxton (G-S) algorithm. It uses the multiple G-S algorithm for reconstructing the light phase created by the substance.  Changing the substance composition affects its optical properties which results with changes in the light phase that can be measured by the light phase standard deviation (STD).

The technique is implemented in two applications: the detection and depth determination of nanoparticles (NPs) in tissues and as an en route to the design of a novel milk-content-monitoring tool.

A simulation that calculates the light phase STD for different substances thickness and µs‘ was developed using reflection and transmission measurements. The results of the simulation indicate a linear ratio between the STD and the scattering components.
Applying the technique on detection of NPs within tissues, a linear ratio was also observed in the experiments of tissue-like phantoms and chicken skin with and without different types of NPs. The NPs presence within the tissue was observed by the change in STD which was up to 40% when the NPs were added.  
Appling the technique to design a monitoring tool for milk content, the effect of different milk components (Lactose and milk proteins) was examined. Our results show that we are able to detect the possibility of lactose and milk proteins’ quantitative signature.

 

Figure 1. The experimental setup.

 

 

 

[102] THREE-DIMENSIONAL METALLIC NETWORKS: AN INNOVATIVE SYNTHETIC STRATEGY AND OPTICAL PROPERTIES

 

Racheli Ron1, Adi Salomon1

 

 

1 Bar Ilan; Bar Ilan

 

 

 

Three-Dimensional Metallic Networks: An innovative synthetic strategy and optical properties

Racheli Ron, Adi Salomon

Department of chemistry, institution of nanotechnology, Bar-Ilan University.

Granting a large-scale piece of metal with a nanoscale architecture of a three-dimensional (3D) continues network provides a new material with novel optical properties. The network is made of interconnected metallic nano-sized ligaments of about 50 nm and connective percolating (open-cell) nano-pores. Such 3D metallic networks are colored similar to solution dispersed metallic silver and gold nanoparticles. Moreover, they exhibit high optical transparency and electrical conductivity. In regards with gold, silver and aluminum, these three-dimensional networks were found to support localized surface plasmon resonance (LSPR) and surface plasmon polaritons (SPP). Therefore, allow very high electromagnetic field enhancement in both large-scale and in three-dimensional manners. We characterize the unique opto-electronic properties of such metallic nano-architecture networks. Metal having this form can find potential applications in a great number of fields, such that functioning in photo-electric devices or as IR detectors since such gold networks possess very high transparencies at the near IR range.

 

 

 

[107] “POLARIMETRIC COLOR SORTER AT THE SUB-MICRON SCALE”

 

Elad Segal1, Adam Weissman1, David Gachet2, Adi Salomon3

 

 

1 Bar-Ilan University; Bar-Ilan University

 

 

2 Attolight; Attolight

 

 

3 Bar Ilan; Bar Ilan

 

 

 

“POLARIMETRIC COLOR SORTER AT THE SUB-MICRON SCALE”

Elad Segal a, Adam weissman a, David gachet b, and Adi Salomon a*

a Department of Chemistry, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.

b Physics/Applications, Attolight AG, Lausanne, Switzerland.

 

Abstract: 

In this work we present an active plasmonic sub-micron device (fig. 1), which consists of a pentameric structure. The pentameric components are five identical triangular nano-cavities that are milled in a 200 nm silver opaque film. We use the hybridization between these metallic nano cavities to form new modes of plasmonic coupling, which is induced by a combination of localized and propagating surface plasmons (LSP and SPP). By tuning the polarization or the distance between these triangles, we are able to achieve suppression or enhancement of the field at specific frequencies. Herein, by minimizing the lateral device size to 200 nm (the triangular side-arm length), and less than 2 microns in length, we push the possible resolution to further increase. In addition, besides of transmission collection, we have closely inspected the fundamental behavior of the coupled entities by cathodo-luminescence (CL) measurements combined of spectra extraction and regional mapping.

 

 

 

 

 

 

 

Figure 1. “Rainbow of plasmonics”, the image depicts the simplicity of possible modes which can be obtained by easily changing either the polarization, or the distance between the coupled nano-triangular cavities (transmission image).

 

 

 

[113] DESIGNING PLASMON-MOLECULE INTERACTIONS

 

Lihi Efremushkin1, Adi Salomon2

 

 

1 Institute of Nanotechnology, Bar-Ilan University; Institute of Nanotechnology, Bar-Ilan University

 

 

2 Bar Ilan; Bar Ilan

 

 

 

Designing Plasmon-Molecule Interactions

Lihi Efremushkin and Dr. Adi Salomon

Department of Chemistry, Institute of Nanotechnology, Bar-Ilan University, Ramat-Gan, Israel

 

In this work we show theoretically and experimentally that a molecular system at very low concentration can be strongly coupled to plasmonic modes. Upon coupling new hybrid states are formed, lower and higher polaritons. These modes have the characteristics of both molecular and plasmonic states and also new characteristic different from those of the molecular and plasmonic states. As the coupling strength grows increasing of molecular concentration asymmetric splitting is observed giving rise to enhanced transmission through metallic hole arrays. Moreover, we have also succeeded in reaching a linear dependency of the Rabi splitting value on the square root of the absorbance which is another proof for strong coupling.

We also show that by tuning the plasmonic modes we are able to be on/off resonance with respect to the molecular system and therefore generate new photonic-exciton hybrid states at different energies and as a consequence with unique properties. Moreover, we show that by changing the distance between the plasmons and the molecules we can design the strong interactions between the two systems.

 

 

 

[124] DESIGN OF A 1X2 SILICON-GALLIUM NITRIDE WAVELENGTH DEMULTIPLEXER BASED ON MULTIMODE INTERFERENCE IN SLOT WAVEGUIDE STRUCTURES

 

Dror Malka1

 

 

1 Bar Ilan University; Bar Ilan University

 

 

 

Design of a 1×2 Silicon-Gallium Nitride Wavelength Demultiplexer based on Multimode Interference in Slot Waveguide Structures

Dror Malka* and Zeev Zalevsky

 

Faculty of Engineering Bar-Ilan University, Ramat-Gan 52900, Israel

*Corresponding author: dror.malka@biu.ac.il

Abstract

In this paper we present 1×2 wavelength demultiplexer operating at 1.3µm and 1.55µm wavelengths, based on multimode interference (MMI) coupler in slot waveguide structure. Gallium nitride was used as the slot material. The design is based on 1×2 MMI coupler demultiplexers.

Since the slot waveguide encompasses true guided modes, confined by total internal reflections, there are no noticeable confinement losses. Full vectorial-beam propagation method (FV-BPM) and BPM simulations were used for optimizing the device parameters and assessing its performance. To the best of our knowledge it is the first time that a 1×2 demultiplexer is being implemented by a slot waveguide based MMI.  In slot waveguide there is a strong electric field confinement in the low-index material (slot area) which leads to high power level in that region. This cannot be achieved in conventional waveguides, therefore there is a benefit using a slot-waveguide for realizing a 1×2 wavelength demultiplexer for optics communication.

Through simulation results, it has been shown that two wavelengths 1.3/1.55µm can be separated after propagation length of 150µm (Figs. 1(a)-(b)). The insertion losses of the proposed device are below 0.14dB for all two wavelengths and the cross talk is below -15dB. These low loss values indicate that such device can be used in wavelength division multiplexing (WDM) systems.

         (a)                                        (b)

Fig. 1. Intensity profile of the 1×4 MMI wavelength demultiplexer: (a). λ1=1.55µm. (b). λ2=1.3µm.

 

 

 

[130] ELECTRICAL EXCITATION AND IMAGING OF OPTICAL NANOPLASMONS

 

Moshik Cohen1

 

 

1 Bar Ilan Universiry; Bar-Ilan Institute of Nanotechnology and Advanced Materials

 

 

 

Electrical Excitation and Imaging of Optical Nanoplasmons

Moshik Cohen* 1,2, Yossi Abulafia2 and Zeev Zalevsky1,2

1Faculty of Engineering, Bar-Ilan University, Ramat-Gan 52900, Israel

2Bar-Ilan Institute for Nanotechnology & Advanced Materials, Ramat-Gan 52900, Israel

 

When light interact with metals it may excite collective electronic excitations known as surface plasmon polaritons (SPPs). These electromagnetic waves are of high intensities and nanoscale dimensions, properties that enable horizons for new fundamental research directions alongside exciting applications ranging from energy harvesting to biomedical nano – imaging1,2. It was experimentally observed that SPPs could also be excited using high-energy electron irradiation of nanometallic structures. However, direct imaging and nanomeasurements of SPPs using scanning electron beam is yet to be introduced. Here we experimentally demonstrate simultaneous direct excitation and rapid nano – imaging of optical plasmons, entirely based on scanning electron microscopy (SEM). We tested plasmonic slot waveguides coupled with dipole nanoantennas and quantitatively characterize both SPs and SPPs. Our results are supported by 3D numerical calculation and by an analytical model.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1 | Plasmonic excitation and nanoimaging with Secondary Electrons. a, SEM topography mapping of the analyzed device obtained with low beam energy (5KeV) and current (25pA).b, SEM (SEE) response of the device under excitation via high energy, focused electron beam (50KeV, 2nm). c, 3D numerical simulation showing the electric field magnitude |E| of the device, when excited by a 50KeV, 2nm electron beam.  Scale bar: 100nm.      

 

To our knowledge, this is the first demonstration of all electrical excitation and imaging of optical plasmons, which rapidly generates high-resolution images and enables quantitative analysis. Our findings open new pathways for electrical investigation of optical nanoplasmonic devices; expanding the route towards merging electrons photons and plasmons on a single integrated platform.

 

1.Cohen, M., Zalevsky, Z. & Shavit, R. Towards integrated nanoplasmonic logic circuitry. Nanoscale 5, 5442–5449 (2013).

2.Cohen, M., Shavit, R. & Zalevsky, Z. Observing Optical Plasmons on a Single Nanometer Scale. Sci. Rep. 4, (2014).

 

 

 

 

 

[134] A SIMPLIFIED METHOD FOR GENERATING PERIODIC NANOSTRUCTURES BY INTERFERENCE LITHOGRAPHY WITHOUT THE USE OF AN ANTI-REFLECTION COATING

 

omree kapon1

 

 

1 Bar-Ilan University; Bar-Ilan University

 

 

 

 

Abstract

 

Interference lithography has proven to be a useful technique for generating periodic sub-diffraction limited nanostructures. Interference lithography can be implemented by exposing a photoresist polymer to laser light using a two-beam arrangement or more simply a one beam configuration based on a Lloyd’s Mirror Interferometer. For typical photoresist layers, an anti-reflection coating must be deposited on the substrate to prevent adverse reflections from cancelling the holographic pattern of the interfering beams. For silicon substrates, such coatings are typically multilayered and complex in composition. By thinning the photoresist layer to a thickness well below the quarter wavelength of the exposing beam, we demonstrate that interference gratings can be generated without an anti-reflection coating on the substrate. We used ammonium dichromate doped polyvinyl alcohol as the positive photoresist because it provides excellent pinhole free layers down to thicknesses of 40 nm, and can be cross-linked by a low-cost single mode 457 nm laser, and can be etched in water.  Gratings with a period of 320 nm and depth of 4 nm were realized, as well as a variety of morphologies depending on the photoresist thickness. This simplified interference lithography technique promises to be useful for generating periodic nanostructures with high fidelity and minimal substrate treatments.

 

 

 

[140] TAILORING NANO-STRUCTURES TO ENHANCE THE RAMAN SCATTERING FROM FULLERENE C60

 

Miri Sinwani1, Yaakov Tischler1

 

 

1 Bar-Ilan Institute of Nanotechnology and Advanced Materials; Bar-Ilan University

 

 

 

Tailoring nano-structures to enhance the Raman scattering from fullerene C60

Understanding the mechanism of surface enhanced Raman scattering (SERS) phenomena is essential for advancing SERS devices for developing the next generation of Raman sensors. Conventional studies investigate the excitation wavelength dependence for certain nanostructure morphologies. However, more comprehension of SERS mechanism can be gained when combining the excitation wavelength dependence with the metal morphology dependence. Here, we report a SERS study of Fullerene C60 thermally evaporated on Au thin film (40 nm) with dense nano-island morphology, and on Au ultra-thin film (2 nm) with nanoparticle morphology. Each sample was measured with two excitation wavelengths: 532 nm and 784 nm. Excitation wavelength of 532 nm generated similar SERS spectra from both Au surfaces. In addition, these SERS spectra fully correlated with regular Raman spectra, strongly indicating a resonance Raman mechanism. In contrast, excitation wavelength of 784 nm caused different SERS spectra in which the SERS intensity, measured from the Au ultra-thin film surface, was 10 times higher than the SERS signal from the Au thin film. The spectral diversity implies an electromagnetic mechanism controlled by near field interactions of local surface plasmon resonances (LSPR).  To strengthen our conclusions, we measured the emission spectrum of each Au surface with both 532 nm and 784 nm excitation wavelengths. While the emission spectra with 784 nm excitation revealed LSPR that correlated with the SERS spectra, the emission spectra of 532 nm excitation did not correspond with the obtained SERS spectra. This connection between emission spectra and SERS spectra of the C60 molecule is attributed to the LSPR overlapping with the energy level manifold of the C60.    

 

 

 

[141] MINIMAL INVASIVE MICRO-ENDOSCOPE IMAGING IN SCATTERING MEDIA ENVIRONMENT

 

omer wagner1, Aditya Pandya2, Irina Schelkanova2, Asaf  Shahmoon1, Alexandre  Douplik2, Zeev Zalevsky3

 

 

1 Bar Ilan Uni.; Bar Ilan Uni.

 

 

2 Ryerson University; Ryerson University

 

 

3 Bar Ilan University; Bar Ilan University

 

 

 

 

Minimal invasive micro-endoscope imaging in scattering media environment

 

Omer Wagner1,*, Aditya Pandya2, Irina Schelkanova2, Asaf Shahmoon1, Alexandre Douplik2, and Zeev Zalevsky1

 

1Faculty of Engineering, Bar-Ilan University, Ramat-Gan 52900, Israel

2Physics Department, Ryerson University, Toronto, Canada

 

Abstract –

Imaging through scattering media is a very applicative field, especially for minimal invasive imaging in biomedical research, medicine etc where imaging through tissues pose a big challenge. Common micro endoscope configurations use gradient refractive index (GRIN) microlenses, which allow wide imaging range. However, the GRIN lens is limited by the mechanical rigidity, length and endoscopes diameter, which may prevent it to reach deep internal organs without damaging their functionality. A different micro endoscope configuration is based on multi core fiber. In this case, the imaging device consists of a few thousand and up to a few tens of thousands of step-index single mode cores which are incorporate together to perform the required imaging operation. The fiber is hard contacted to the sample.         
In this work we use a specially fabricated micro endoscope multi core fiber having cores of 0.5 micron in size with 2 micrometer pitch between cores, to image samples that are located inside an environmental scattering media. We have succeeded to image 30 µm in tissue channels (e.g. blood vessels) through a scattering media of up to 360 µm thick with scattering coefficient of μs’=0.993mm-1.

 

 

 

 

[149] SECOND HARMONIC GENERATION FOR ELECTRODE SURFACE IMAGING

 

hannah aharon1, Adi Salomon2

 

 

1 Bar Ilan University ; Max and Anna Webb

 

 

2 Bar Ilan; Bar Ilan

 

 

 

Second Harmonic Generation for Electrode Surface Imaging

Hannah Aharon and Adi Salomon

Understanding the chemistry on the surface of electrochemical electrodes is a major obstacle in the development and understanding of rechargeable batteries and fuel cells. With our lab built Second Harmonic Generation (SHG) setup, we look into these interactions by means of nonlinear optics. SHG generation is blind to any bulk centrosymmetric material and can therefore be focused on the electrode surface without interference from the bulk electrode or the electrolyte. Following the changes the electrode undergoes due to voltage, electrochemical charging and discharging etc. are made feasible due to our custom made battery cell. These measurements are performed in- and ex-  situ. We show that even the slightest bias applied to an electrode effects the SHG signal. This is due to the unique sensitivity of SHG electrostatic properties and polarization of surfaces.

 

 

 

[170] TWEEZERS CONTROLLED RESONATORS

 

Samuel Kaminski1

 

 

1 Technion; 32000

 

 

 

Tweezers Controlled resonators

 

We experimentally demonstrate trapping a  micro-droplet with an optical tweezers and then functionalize it as a micro-resonator by bringing it close to a tapered fiber coupler.  Our tweezers facilitated tuning of the coupling from the under-coupled to the critical coupling regime with an optical Q of 12 million and micro-resonator size at the 85 um scale. We prove the concept of using an optical trap for activating oil droplets as fiber-coupled micro-resonators. We believe that our technique will extend to several resonators and then to an optical circuit where the shape and position of many optical devices will be controlled.

 Our long-term vision includes optical circuits where a multi-minima optical trap shapes and positions multiple resonators. Being practical, we start here with modestly proving this concept by activating one µdrop as a resonator, and using an optical trap to hold and position it next to a tapered-fiber coupler.

 

 

 

[176] REINTERPRETING THE MAGNETOELECTRIC COUPLING OF INFINITECYLINDERS USING SYMMETRY: A SIMPLE TM/TE VIEW

 

Parry Chen1, Jacob Ben-Yakar1, Yonatan  Sivan2

 

 

1 School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences; Tel Aviv University

 

 

2 Unit of Electro-Optical Engineering; Ben Gurion University

 

 

 

Periodic arrays of long circular cylinders, whether metallic or dielectric, are key components of many metamaterial designs. These include all-dielectric optical metamaterials, hyperbolic media, super-resolution endoscopes, drawn metamaterial fibers, and single-molecule bio-sensors. Characterizing the response of individual cylinders is a fundamental step towards the effective electromagnetic response. For optically thin cylinders, scattering is adequately described by dipoles, considerably simplifying subsequent treatment by effective medium theories, ultimately yielding ε and μ.

This proceeds by analogy to the polarizability tensor α of a molecule. When α is diagonal, only electric fields can induce electric dipoles. A general metamaterial element may also have non-zero off-diagonal blocks, representing magnetoelectric coupling whereby magnetic fields induce electric dipole moments. Despite its fundamental importance, the literature retrieving the full polarizability tensor of cylinders is sparse, considered by only one publication to our knowledge. Surprisingly, a magnetoelectric coupling was reported [1], which only arises in non-centrosymmetric scatterers such as split ring resonators.

We delve into the physical origins of this coupling, establishing insight which is critical to the design of metamaterials exhibiting artificial magnetism. We show that a simple decomposition of α into its TM/TE components restores the expected diagonal response through a transformation we derive, supplying an analytically simpler formulation. Our key insight is that off-diagonal magnetoelectric coupling terms account for the difference between TM/TE responses, allowing two dissimilar diagonal responses to be combined onto a single tensor.

This provides ready explanations for the unusual magnetoelectric coupling of infinite cylinders, which for example changes sign when angles of incidence are inverted, and disappears when counterpropagating waves are impinging. Our analysis explains why magnetoelectric coupling exhibits weak k4 scaling for dielectric cylinders at long wavelengths, k2 scaling for perfect electric conductors, but becomes prominent at Mie resonances. Unlike structures without inversion symmetry though, the strengths of magnetoelectric resonances cannot differ from both its corresponding electric and magnetic resonances.

[1] D. Strickland et al., PRB 91 (8), 085104 (2015)

 

 

 

[210] NOVELL XUV SPECTROMETER FOR NANOMATERIAL ANALYSIS IN SCANNING ELECTRON MICROSCOPE

 

Alexei Erko1, Aljosa Hafner1, Alexander Firsov1

 

 

1 Institute for Nanometer Optics and Technology; Helmholtz Zentrum Berlin

 

 

 

Nano- structuring technology: e-beam lithography and reactive ion etching, were used for fabrication of spectrometric X-ray optical elements with minimal structure period down to 80 nm. Here we are reporting on a 17-element, 14-element (both discrete energy) and a 200-element (quasi-continuous) reflection zone plate (RZP) spectrometer, newly designed for XUV fluorescence emission spectra analysis of nanomaterials with scanning electron microscopes. The 14-channel optical element is designed specifically for X-ray emission spectra of ultralight elements such as Mg and Li compounds, Al L- and Si L-lines in the energy range of 45 eV – 100 eV. The 17-channel optical element covers an energy range from 54 eV to 1120 eV. The energy resolution, measured on the Al L-peak to be 0.5 eV eV and the overall resolving power is on the order of E/ΔE ~ 80-160.

 

  1. Hafner et al., Optics Express, 23, (23), (2015), 29476
  2. A Erko et al., Optics Express 22 (14), (2014), 16897-16902

 

 

 

[216] NANO-ANTENNAS FOR SPATIAL ADDRESSING OF SPIN STATES IN DIAMONDS

 

Tzach Jaffe1

 

 

1 Technion; Israel Institute of Technology

 

 

 

 

Nano-antennas for Spatial Addressing of Spin States in Diamonds

Tzach Jaffe, Ofir Sorias and  Meir Orenstein.

 Department of Electrical Engineering, Technion – Israel Institute of Technology, 32000 Haifa, Israel.

tzahifa@tx.technion.ac.il

Abstract: The negatively charged Nitrogen-Vacancy (NV) color center in diamond is an important physical system for emergent quantum technologies and sensing at room temperature. We propose and experimentally demonstrate a selective and spatially localized way to address the spin states of the NV center, by a plasmonic antenna tuned to modify the NV’s emission and absorption spectra.

The NV center is a multi-electron system which allows us to address its spin state with optical light. Different methods for addressing and controlling the spin states of NV centers have been thoroughly investigated in recent years, but currently there is no efficient way to selectively address NV center in regular bulk diamond. In order to achieve that, we have to overcome the inherent mismatch between the wavelength of excitation and the size of the NV center, and at the same time to modify its emission and absorption spectra. For that reason we chose to combine the NV’s properties with localized plasmonics.

We investigated theoretically and experimentally a specific plasmonic antenna, denoted here as the “Templar Cross (TC) Antenna”, in order to enhance the excitation power and to increase the photonic density of states for enhanced emission, in its vicinity. We experimentally demonstrate performance enhancement which highlights its potential for spatial control over initialization and readout of the system’s spin state, with a polarization dependency (Figure 1).

Figure 1 – (a) SEM image of a TC antennas array; (b) Reflection measurement from the array for two polarizations – X and Y; (c,d) NSOM measurement and near field simulation results of the intensity enhancement (up to 3 orders of magnitude) due to two types of resonances in the structure (Logarithmic scale colorbar); (e,f) Measurements of the NV’s NIR and visible emission spectra respectively.

 

 

 

[244] DIRECT 3D NANOPRINTING ON FIBER TIP OF COLLIMATING LENS AND OAM MODE CONVERTER IN ONE COMPOUND ELEMENT

 

Israel Weiss1, Dan Marom1

 

 

1 Hebrew University of Jerusalem; Applied Physics Department

 

 

 

Optical fibers are widely used as an efficient and flexible light transmission medium that is well protected from the environment. The fiber facet is an opportune location for placement of structures and devices for interaction with light.

Here we present 3D nano printing process directly on optical fiber tip using a commercial 3D laser lithography system of “Nanoscribe GmbH” employing immersion technology. We optimized the fabrication process in terms of surface smoothness, volume homogeneity and writing speed in order to reach high optical quality of the fabricated elements. This ability gives us wide leeway for realizing sophisticated optical elements in the nano-scale in order to control the light efficiently and accurately at the fiber tip. In that project we demonstrate the direct nanoprinting of a 3D collimating lens suspended above the fiber with an azimuthal phase for creating an OAM beam.

As a preliminary step, we printed the device on a flat glass substrate. By projecting light on the device through a cleaved fiber, we were able to observe the OAM ring intensity profile (Figure 1 a) as well as the interference pattern with the Gaussian mode (Figure 1 b,c), by adjusting the distance between the fiber and the device.

Next, we designed and fabricated a spherical lens with azimuthal spiral phase plate on top of it. The lens was designed with radius of curvature of 25um, meaning focus length of about 50um (Figure 2, Designed sketch (a) and SEM images (b-d) of the device). The spiral phase plate is encoded on top of the spherical lens with the same radius of curvature, and with a phase step of 2pi along a radius section of the device. The whole structure is printed on top of supporters with height of 50um, designed so that the light will be collimated at the exit of the device.

 

 

 

[331] ULTRAFAST PULSE GENERATION USING TRANSIENT BRAGG GRATINGS IN OPTICAL FIBERS & WAVEGUIDES

 

Aviran Halstuch1

 

 

1 Hagefen 56; Hagefen 56

 

 

 

Ultrafast pulse generation using transient Bragg gratings in optical fibers & waveguides

Aviran Halstuch, Shai Rozenberg, Amiel A. Ishaaya, Yonatan Sivan
Faculty of Engineering Sciences, Ben-Gurion University of the Negev, Israel

Commercial fiber lasers are currently operational only at a limited set of wavelengths (e.g 1µm, 1.5µm, 2µm) or other few operational wavelengths generated by nonlinear conversion based on chi-2 materials or Raman amplification. It is also known that such lasers with pulse durations between several picoseconds to 1 nanosecond are indeed scarce, since this regime is between Q-switching and mode-locking.

In this work we introduce and demonstrate theoretically a flexible yet simple scheme to generate ultrashort pulses at arbitrary wavelength and duration via spectral inheritance, whereby a spectrally-narrow pulse “inherits” the wide spectrum of a pump pulse centered at a different wavelength. Moreover, our scheme provides a new route for spatio-temporal pulse shaping and further practical advantages such as pulse-to-pulse control.

The suggested scheme enables such spectral “inheritance” by introducing a transient Bragg grating (TBG) in an optical waveguide/fiber. The TBG can be induced via Cross-phase modulation in Kerr media, or more efficiently using free-carrier or even thermal nonlinearities. Various parameters such as: spatial profile, temporal profile, intensity and wavelength, of the induced TBG affect the duration and intensity of the reflected pulse generated.

The concept was demonstrated via exact numerical solution of the Maxwell equations by using FDTD methods. A simplified model was derived based on an extension of standard coupled mode theory equations. We show excellent agreement between these various approaches.

Specifically, we demonstrate backward pulse durations of ~150-200ps in silica fibers. Shorter pulses down to ~ 1ps can be generated at lower efficiencies. However, improved efficiency level up to ~50% can be achieved for such short pulses by using a stronger, slower nonlinear process, e.g., free carrier nonlinearity in silicon.

Finally, we review the experimental demonstration of spectral inheritance in both silica fibers and silicon waveguides.

 

 

 

 

 

 

[346] LASER AND PLASMONIC COUPLED MODES

 

shir shahal1, Hamootal  Duadi2, moti Fridman1

 

 

1 Bar Ilan University; Institute for Nanotechnology and Advanced Materials

 

 

2 Bar Ilan University; Institute of Nanotechnology and Advanced Materials

 

 

 

Laser and plasmonic coupled modes

Shir Shahal, Hamootal Duadi and Moti Fridman 

Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan, 52900, Israel

Excitation of free electrons which oscillate in resonance along a metal surface, are called Surface Plasmon Polaritons (SPPs). SPPs have been the subject of intensive research for the past few decades, and play a role in manipulating electromagnetic fields from the visible to the infrared spectra, both in linear and non-linear optics. Periodic hole arrays in a metal film are convenient structures to achieve the coupling of light to SPPs, since their spectral properties can be tuned and scaled by adjusting the size and geometry of the holes. When a light beam is in resonance with the periodic hole array the transmission of light is increased. This effect is called enhanced transparency.

Until now there was a little research about the spatial plasmonic modes in enhanced transparency. We investigate the spatial modes of enhanced transparency in gold and tungsten films, which have a periodic sub-wavelength hole array, by imposing interaction between the SPPs modes and the spatial modes of a laser diode.

Our experiment is based on placing a sub-wavelength hole array written on a metal plate at the focal plane of a degenerate cavity laser and measuring the transmission modes. As a first step we placed a single, variable size slit at the focal plane, and measured the transmission modes through the plate.

We will present our current results, along with our experimental set up and methods.   

 

 

 

[350] NONLINEAR WAVE MIXING IN PLASMONIC STRUCTURES : A TRANSFORMATION OPTICS

 

Nireekshan Reddy Kothakapu1, Antonio Fernandez-Dominguez2, Yonatan  Sivan3

 

 

1 Ben-Gurion University; Ben-Gurion University

 

 

2 Universidad Autonoma de Madrid; Universidad Autonoma de Madrid

 

 

3 Unit of Electro-Optical Engineering; Ben Gurion University

 

 

 

Nonlinear Wave Mixing in Plasmonic Structures : A Transformation Optics

  1. Nireekshan Reddy1, Antonio I. Fernandez-Dominguez2 and Yonatan Sivan1

1) Unit of Electro-Optic Engineering, Ben-Gurion University, Beer-Sheva 8410501,Israel

2) Departamento de Fisica Teorica de la Materia Condensada, Universidad Autonoma de

Madrid, E-28049 Madrid, Spain.

Keywords:  Nano-Optics, Second-Harmonic Generation

 

Singular structures in plasmonics, for example, touching wires, crescent cylinders, etc., are well known for enhancing the field in small volumes by several orders of magnitude. Recent studies revealed that transformation optics can provide a very powerful analytical tool to solve these class of problems. It was also pointed out that these class of structures can also be suitable candidates for energy harvesting and field enhancements were calculated to be as high as 104 close to singular points. We review some of the theoretical and the experimental results of the linear properties of these structures.

Such high field enhancement would definitely invoke the nonlinear phenomenon. Our present study analytically incorporates such nonlinear phenomenon from χ(2) materials initially focusing on second-harmonic generation. We follow the route of conformal transformation optics but now extending it to nonlinear materials. To the best of our knowledge there have been no reports on such analytical techniques describing nonlinear optics at nanoscale. We identify the relations for phase and amplitude matching for the second-harmonic fields. Our approach also connects with the standard coupled-mode theory used in “macro-optics” structures such as waveguide to the Green’s function approach which is extensively used in nano-optics. We identify the optimal conditions for second-harmonic generation efficiency. This approach is the starting point to understand various other nonlinear interactions such as three and four-wave mixing in singular structures.

References:

 [1] J. B. Pendry, A. Aubry, D. R. Smith, S. A. Maier,Transformation Optics and Subwavelength Control of Light,” Science 337, 549 (2012)

 

 

 

[382] EXCITATION OF LP MODES THROUGH LPFG

 

Gilad Masri1, Mordechai Fridman1, Shir Shahal1, Hamootal  Duadi2

 

 

1 Bar-Ilan University; Institute of Nano Technology

 

 

2 Bar Ilan University; Institute of Nanotechnology and Advanced Materials

 

 

 

15.11.2015

Bar-Ilan University

Faculty of Engineering

Excitation of LP modes through LPFG

Gilad Masri, Shir Shahal, Hamutal Duadi, Moti Fridman

Faculty of Engineering and the BINA center for nanotechnology, Bar Ilan University

            We present a method for exciting linearly polarized (LP) Electromagnetic Field modes with a Long-Period Fiber Grating (LPFG). We wrote the LPFG by tailoring the mechanical oscillations of a fiber while tapering it. We investigated the output mode as a function of the input wavelength, and found that the LPFG causes energy transfer from the LP01 Gaussian-profile mode to higher LPlm modes for specific input wavelengths. The results are compared to a calculated model. In this model we relate the modal dynamic of the light to variations in the spatial direction of the light’s photon momentum imposed by the LPFG. This research can lead to a new method of real-time spectral detection of light sources and the ability to decompose the EM Field into several LPlm modes. Potential applications are wavelength-sensitive sensors for temperature, chemical and mechanical stress analysis. The experimental scheme and results together with the calculated results will be presented.

 

 

 

[402] “NOVEL SILICON NANOWIRES COLOR DETECTORS FOR THE USE IN OPTOELECTRIC APPLICATIONS”

 

Sharon Lefler1

 

 

1 Group of Prof” Patolsky, School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences,; Center for Nanoscience and Nanotechnology

 

 

 

The absorbance spectrum of silicon lays under ~1,1000nm which enables silicon to detect visible light. However silicon-based photo detectors cannot distinguish between different wavelengths. Therefore, these detectors relay on color-specific pre-filters to achieve color separation. These color filters add complexity to color sensitive device fabrication and hinder the miniaturization of such devices. Only recently, the first color-specific non-silicon based detectors were reported, utilizing complex thick, and thin, film photodiodes based on perovskite crystals. Nevertheless, these perovskite-based photodetectors are at a millimeter-scale, and cannot be incorporated into present silicon-based integrated circuits. Here, we present the use of novel molecularly-embedded silicon nanowires (SiNWs) which can detect different and specific wavelengths, without the use of filters or waveguides. These Nano Color-Specific Field Effect Transistors (NCS-FETs) can detect at least 4 distinct colors, red- green-blue-UV (RGB+UV). Upon wavelength specific excitation, the NCS-FETs can retain significant part of their current for long periods of time, post excitation, serving as memory elements. We can also control the ‘on’-‘off’ state of the NCS-FETs all-optically, without the use of electric gate. These NCS-FETs devices operate well under ambient conditions, and were found to be stable for months from their fabrication date. All together, these NCS-FETs can be utilized in many experimental and commercial applications, ranging from small pixel-size photodetectors, nonvolatile optoelectric memory devices and bio-sensing related applications.

 

 

 

 

[406] TAILORING LIGHT BY 3D DIRECT LASER-WRITING FABRICATED MICROSTRUCTURES

 

shlomi lightman1

 

 

1 Tel Aviv University; Tel Aviv University

 

 

 

Tailoring light by 3D direct laser-writing fabricated microstructures

Shlomi Lightman1,3, Raz Gvishi1, Ehud Galun2, and Ady Arie3

1Electro-optics Division, Soreq NRC, Yavne 81800, Israel

2DDR & D IMOD, Hakirya, Tel Aviv, Isarel

3Department of Physical Electronics, School of Electrical Engineering, Tel Aviv University, Tel Aviv 69978, Israel

 

The ability to manipulate light beams has become a key factor in many areas of science, as it is possible to generate beams of complex structures. Hence, an astonishingly wide range of prospective applications have emerged because of this capability: noncontact optical manipulation of matter (optical tweezers), subwavelength resolution microscopy, nanofabrication, laser cooling (atom trapping) and so on. Many of these methods exploit the distinctive properties of each generated beam, such as phase properties, spatial intensity distributions and (orbital\spin) angular momentum. These new light beams can be generated in several ways, as the key element is the change of phase or amplitude of the original beam. In principle, phase modulation is a better approach than amplitude modulation, mainly since the latter is lossy and splits the incoming beam into multiple diffraction orders. The conventional ways of generating phase modulation have several drawbacks, as custom-made optical devices are usually manufactured by a long, multiple-step, fabrication process; and electrically driven liquid-crystal mediums, i.e. spatial light modulators, are expensive, planar and cannot be integrated. Here we demonstrate phase modulation of light beams, by harnessing a 3D-Direct laser writing lithography process. With this fabrication capability, arbitrary micron-scale structures can be written directly onto optical elements (e.g. nonlinear crystals, lenses and various substrates), as they modify the phase of the incoming light, by corresponding to a desired phase modulation. This enables structuring complicated beams, acquire mode sorting capability of orbital angular momentum beams, and reduce lens aberrations by correcting elements, in a compact, stable and cost effective routine.

 

 

 

 

 

[416] EXPERIMENTAL SYSTEM OF THE FULL SCATTERING PROFILE OF CIRCULAR PHANTOMS

 

Idit Feder1, Hamootal  Duadi2, Dror Fixler2

 

 

1 Bar-Ilan University; Institute of Nanotechnology and Advanced Materials

 

 

2 Bar Ilan University; Institute of Nanotechnology and Advanced Materials

 

 

 

Experimental system of the full scattering profile of circular phantoms

Idit Feder, Hamootal Duadi, Rinat Ankri and Dror Fixler

Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Israel

Human tissue is one of the most complex optical media since it is turbid and nonhomogeneous. We suggest a new optical method for sensing physiological tissue state, based on the collection of the ejected light at all exit angles, to receive the full scattering profile. We simulate the light propagation in homogenous and heterogeneous cylindrical tissues and obtain the full scattering profile. In addition we built a unique set-up for noninvasive encircled measurement. We use a laser, a photodetector and tissues-like phantoms presenting different diameters and different reduced scattering coefficients. Our method reveals an isobaric point, which is independent of the optical properties and linearly depends on the exact tissue geometry. Furthermore, while adding nanoparticles to the tissue our new method can detect it due to the change they cause in the reduced scattering coefficient. In our previous work, nanoparticles have been defined as contrast agents for diagnostics and treatment of different physiological conditions, such as cancer and atherosclerosis. In addition, the blood vessels in human tissues are the main cause of light absorbing and also scattering. Therefore, the effect of blood vessels on light-tissue interactions is essential for biomedical applications based on optically sensing, such as oxygen saturation, blood perfusion and blood pressure. We show the vessel diameter influence on the full scattering profile, and found higher reflection intensity for larger vessel diameters accordance to the shielding effect. These findings can be useful for biomedical applications such as non-invasive and simple diagnostic of the fingertip joint, ear lobe and pinched tissues.

 

 

 

[420] FEMTOSECOND-SCALE SWITCHING BASED ON EXCITED FREE-CARRIERS

 

marat spector1, Yonatan  Sivan2

 

 

1 Ben Gurion University of the Negev; Ben Gurion University of the Negev

 

 

2 Unit of Electro-Optical Engineering; Ben Gurion University

 

 

 

Femtosecond-scale switching based on excited free-carriers

 

 

Ultrafast switching is one of the oldest and most important applications of nonlinear optics. Traditionally, it is based either on Kerr nonlinearity, which is instantaneous, but weak, or on free carrier nonlinearity, which could be much stronger, but comes at the cost of a substantially slower turn-off time.

 

Here, we demonstrate simple schemes that enable us to enjoy the best of the two worlds – to have an ultrafast and strong switching, based on free-carrier generation. Specifically, we describe novel switching schemes operating on femtosecond time scales, which are based on a periodic pattern of free-carriers (FCs) which serves as a transient Bragg grating. Such gratings can be generated by a resonant pumping of a semiconductor or metallic waveguide.

 

In the first realization, we rely on diffusion to erase the initial FC pattern, hence, to remove the reflectivity of the system. We show that the grating erasure time is quadratically proportional to the effective wavelength, so that the high refractive index of semiconductors or the effective index of plasmonic waveguides makes this time scale sub-picosecond under realistic conditions. In the second realization, we erase the FC pattern by launching a second, delayed pump pulse which is shifted by half a period compared with the first one.

 

We discuss the advantages and limitations of the proposed approach and demonstrate it for switching ultrashort pulses propagating in silicon waveguides and plasmonic waveguides. We show reflection efficiencies of up to 50% for 100fs pump pulses, which is an unusually high level of efficiency for such a short interaction time, a result of the use of the strong FC nonlinearity.

 

Due to limitations of saturation and pattern effects, the scheme can be employed for switching applications requiring femtosecond features but standard repetition rates. Such applications include switching and modulations of ultrashort pulses, femtosecond spectroscopy (gating) and time-reversal of short pulses for aberration compensation.

 

 

 

[441] BROADBAND NEAR-INFRARED TO VISIBLE UPCONVERSION IN QUANTUM DOT-QUANTUM WELL HETEROSTRUCTURES

 

Ayelet Teitelboim1, Dan Oron2

 

 

1 Dept. of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel; Weizmann Institute

 

 

2 Department of Physics of Complex Systems; Weizmann Institute of Science

 

 

 

Broadband near-infrared to visible upconversion in quantum dot-quantum well heterostructures

 

Ayelet Teitelboim, Dan Oron.

  1. Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel, 7610001

Abstract:

Upconversion is a nonlinear process in which two, or more, long wavelength photons are converted to a shorter wavelength photon. It holds great promise for bioimaging, enabling spatially resolved imaging in a scattering specimen and for photovoltaic devices as a mean to surpass the Shockley-Queisser efficiency limit. Here, we present dual near-infrared and visible emitting PbSe/CdSe/CdS nanocrystals able to upconvert a broad range of NIR wavelengths to visible emission at room temperature. The synthesis is a three-step process, which enables versatility and tunability of both the visible emission color and the NIR absorption edge. Using this method one can achieve a range of desired upconverted emission peak positions with a suitable NIR band gap.

 

 

 

[469] PHOTONIC AND PLASMONIC NANO-SCALE LIGHT VAPOR INTERACTIONS

 

Liron Stern1, Boris Desiatov1, Meir Grajower1, Noa Mazurski1, Uriel Levy1

 

 

1 Hebrew University of Jerusalem; Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology

 

 

 

Photonic and Plasmonic Nano-Scale Light Vapor Interactions

Liron Stern, Boris Desiatov, Meir Grajower,  Noa Mazurski and Uriel Levy*

Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel

 

Alkali vapors, such as rubidium, are being used extensively in several important fields of research such as slow and stored light non-linear optics quantum computation, atomic clocks and magentometers. Lately, there is a growing effort towards miniaturizing traditional centimeter-size vapor cells. Owing to the significant reduction in device dimensions, light matter interactions are greatly enhanced, enabling new functionalities due to the low power threshold needed for non-linear interactions. Here, we demonstrate the evanescent interaction of both photonic and plasmonic optical modes with Rubidium atoms. First, we demonstrate light-matter interactions in a new generation of atomic cladding wave guide, namely an atomic cladding serpentine waveguide, consisting of a 17mm long silicon nitride nano-waveguide core with a rubidium vapor cladding. We observe the efficient interaction of the electromagnetic guided mode with the rubidium cladding and demonstrate all optical control on a probe signal in the microwatt power regime. Next, we present a novel hybrid plasmonic-atomic system, consisting of a prism coated with a 40nm gold layer integrated with an atomic cell. Using this platform, we demonstrate  the resonance coupling of a surface Plasmon resonance and Rubidium atomic vapor. By introducing a magnetic field, we are able to control the Fano line shapes, and observe the unique selection rules subject to the existence of an evanescent longitudinal electric field component. Both the plasmonic and photonic integrated platforms, are expected to serve as an important building blocks in future applications such as magnetometry, chip scale frequency standards and pulse shaping.  

 

 

 

 

 

 

[472] SPECTROSCOPIC INSIGHT INTO THE INFLUENCE OF CATION EXCHANGE ON THE ANIONIC FRAMEWORK OF QUANTUM DOTS

 

Noga Meir1, Beatriz Martin-Garcia2, Iwan Moreels2, Dan Oron1

 

 

1 Department of Physics of Complex Systems; Weizmann Institute of Science

 

 

2 Department of Nanochemistry; Istituto Italiano DI Technologia

 

 

 

 

 

Spectroscopic Insight into the Influence of Cation Exchange on the Anionic Framework of Quantum Dots

Noga Meir, Beatriz Martin-Garcia, Iwan Moreels, Dan Oron

 

The process of cation exchange in semiconducting nanocrystals has been in use for many years as an important synthetic tool. However, not much attention was given to the possible effect such process can have on the anionic framework of the crystal.

In this study, we used CdSe quantum dots that are doped by only one or a few atoms of Te. These quantum dots exhibit large blue-shift of the biexciton energy due to the presence of the Te dopant. This energy shift is strongly dependent on the size of the CdSe host and the location of the Te dopant. By using simple spectroscopic methods we were able to measure the biexciton energy before and after a back-and-forth cation exchange process (from Cd2+ to Zn2+ and back to Cd2+), and use these measurements in order to assess the effect of the cation exchange process on the crystal structure of the dots.  

 

 

 

[477] SYNTHESIS AND OPTICAL PROPERTIES OF THIN FILMS COMPOSED FROM WS2 NANOTUBES DECORATED WITH GOLD NANOPARTICLES

 

Alexander Polyakov1, Varvara Zubyuk2, Tatiana Dolgova2, Lena Yadgarov3, Bojana Visic4, Andrey Fedyanin2, Reshef Tenne5, Eugene Goodilin1

 

 

1 Lomonosov Moscow State University; Faculty of Materials Science

 

 

2 Lomonosov Moscow State University; Faculty of Physics

 

 

3 Weizmann Institute of Science; Department of Materials and Interfaces

 

 

4 Weizmann Institute of Science ; Department of Materials and Interfaces

 

 

5 Department of Materials and Interfaces; Weizmann Institute of Science

 

 

 

Synthesis and Optical Properties of Thin Films Composed from WS2 Nanotubes Decorated with Gold Nanoparticles

Alexander Polyakov,1 Varvara Zubyuk,2 Tatiana Dolgova2, Lena Yadgarov,3 Bojana Visic,3 Andrey Fedyanin,2  Reshef Tenne,3 Eugene Goodilin1

1 Lomonosov Moscow State University; Faculty of Materials Science, Moscow, Russian Federation

2 Lomonosov Moscow State University; Faculty of Physics, Moscow, Russian Federation

3 Weizmann Institute of Science; Department of Materials and Interfaces, Rehovot, Israel

Thin films of WS2 nanotubes (INT-WS2) decorated with gold nanoparticles are prepared using nanocomposite assemblage on the water-heptane interface and film transition onto optically transparent or semiconducting surfaces. Almost all nanotubes were found to be aligned horizontally within the 1-2 layered films. The film morphology resembles a mosaic structure of 10-25 square micron areas with in-plane textured nanotubes. Within these areas, composite particles change the reflected light polarization identically, as visualized optical microscopy in a near-crossed analyzer configuration. Optical extinction spectra of the films demonstrate several features around 490, 545, and 675 nm similar to the ones in suspension spectra, but with altered intensity ratio, possibly due to high anisotropy of the nanotubes and their texturing peculiarities in the films. At the same time, decoration with gold nanoparticles did not result in appearance of any additional peaks in both suspension and film spectra of the nanocomposites relative to the ones of pristine nanotubes. The same was observed previously for Au-INT-WS2 suspensions and described by low-barrier contact between gold nanoparticles and nanotubes. Reflectance spectra of the INT-WS2 and Au-INT-WS2 films measured using a p-polarized beam revealed an angular dependence of both films reflectance spectra, thus evidencing for the possibility of new optical applications of WS2-based materials in the future.

AYP and EAG thank The Russian Scientific Foundation for financial support (grant 14-13-00871). AYP thanks the Personal Studentship of RF President for young scientists and Ph.D. students (agreement SP-4789.2015.1).

 

 

 

[485] DIRECT OBSERVATION OF ELECTROMAGNETIC NEAR FIELD IN SILICON NANOPHOTONICS DEVICES USING SCANNING THERMAL MICROSCOPY (STHM) TECHNIQUE

 

Meir Grajower1, Liron Stern1, Boris Desiatov1

 

 

1 Hebrew University of Jerusalem; Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology

 

 

 

Direct observation of electromagnetic near field in nanophotonics devices using Scanning Thermal Microscopy (SThM) technique

 

Meir Grajower, Liron Stern, Boris Desiatov, Ilya Goykhman and Uriel Levy

Department of Applied Physics, The Benin School of Engineering and Computer Science, The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel

In recent years, following the miniaturization and integration of passive and active nanophotonic devices, thermal characterization of such devices at the nanoscale is becoming a task of crucial importance. The Scanning Thermal Microscopy (SThM) is a natural candidate for performing this task. However, it turns out that the SThM capability to precisely map the temperature of a photonic sample in the presence of light interacting with the sample is limited. This is because of the significant absorption of light by the SThM probe. As a result, the temperature of the SThM probe increases and a significant electrical signal which is directly proportional to the light intensity is obtained. As such, instead of measuring the temperature of the sample, one may measure the light intensity profile. While this is certainly a limitation in the context of thermal characterization of nanophotonic devices, this very property provides a new opportunity for optical near field characterization. Here we demonstrate numerically and experimentally the optical near field measurements of nanophotonic devices using a SThM probe. The system is characterized using several sets of samples with different properties and various wavelengths of operation. Our measurements indicate that the light absorption by the probe is far more significant than the light induced heat generation in the sample. The simplicity of the SThM system which eliminates the need for complex optical measurement setups together with its broadband wavelength of operation makes this approach an attractive alternative to the more conventional aperture and apertureless NSOM approaches.

 

 

 

[513] SUPER-RESOLUTION MICROSCOPY BY ANTIBUNCHING ASSISTED LOCALIZATION

 

Ron Tenne1, Yonatan Israel1, Yaron Silberberg1, Dan Oron2

 

 

1 Weizmann Institute of Science; Herzl 234

 

 

2 Department of Physics of Complex Systems; Weizmann Institute of Science

 

 

 

Super-Resolution Microscopy by Antibunching Assisted Localization

 

Ron Tenne1, Yonatan Israel1, Yaron Silberberg1 and Dan Oron1

 

1 Department of Physics of Complex Systems, Weizmann Institute of Science, 76100 Rehovot, Israel

 

Super resolution microscopy, the ability to resolve objects smaller than the wavelength of visible light, has developed from a research concept into applicable methods regularly used in biology nowadays. While a variety of methods have been well developed none produces a general route to acquire a super-resolved image. In particular only a handful of methods can incorporate photo-stable quantum dots (QDs) as contrast agents. Here we present ongoing work towards implementing a method relying on the quantum nature of a single quantum dot fluorescence in order to localize them in space and generate a super-resolved image.

 

A Hanbury-Brown and Twiss setup is employed to locate periods in which only a one out of a few blinking QDs is fluorescing. These episodes are then used to localize the position of the emitter with an accuracy of a tenth of the wavelength. Preliminary results showing the localization of two QDs as well as future outlook and obstacles will be presented.

 

 

NANOSCUPTURED THIN FILMS BASED SERS BIOSENSOR: HIGHLY SENSITIVE & SPECIFIC DETECTION OF E. COLI

 

Sachin K. Srivastava *,1a,1b,2,#, Hilla Ben Hamo 1c, Ariel Kushmaro 1b,1c,2, Robert S. Marks 1b,1c,2   Christoph Grüner 3, Bernd Rauschenbach 3,4 and Ibrahim Abdulhalim 1a,1b,2

 

1a.Department of Electro optic Engineering, –

1 b. Ilse Katz Institute for Nanoscale Sciences and Technology, –

1c. The Avram and Stella Goldstein-Goren Department of Biotechnology Engineering,-

– Ben Gurion University of the Negev, Beer Sheva-84105, Israel

  1. NTU-HUJ-BGU CREATE Programme, School of Materials Science and Engineering, Nanyang Technological University, 637722, Singapore,
  2. Leibniz Institute of Surface Modification, Permoserstrasse 15, 04318 Leipzig
  3. University Leipzig, Institute for Experimental Physics II, Linnéstr.5, 04307 Leipzig, Germany

* E-mail:sksrivastava@ntu.edu.sg,   #Present affiliation

 

Nanosculptured thin films (nSTFs) of silver (300 nm height and 30 % porosity over Si substrates) were used to develop a surface enhanced Raman spectroscopy (SERS) based nanobiosensor for very specific detection of E. coli up to the concentration levels of single bacterium [1]. These are columnar films of metal. The sensor chip was fabricated by immobilizing T4- bacteriophages. The sensor was tested for two strains of E. coli (RFM443 (E. coli B) and XLMRF (E. coli μX)] and 3 other gram negative bacteria C. violaceum (CV026), P. dentrificans and P. aeruginosa as negative control experiments.

 

(c)

 

Fig. 1 Sensor Response at1077cm-1 Raman shift of the sensor chip for all the bacteria

 

Fig. 1 shows the difference of the SERS enhancement of the sample on the sensor to that from the bare sensor chip, (Isample – Isensor) for varying bacterial concentrations. It is observed that the sensor response does not change with any increase in concentrations for other kinds of bacteria, while that shows an increase sample solutions of both kinds of E. coli. The sensor utilizes only 10 μl from a solution of 150 cfu/ml concentration, which means detection up to single bacterium.  

 

 

References

  1. Srivastava et al., Analyst 140, 3201-3209 (2015).

 

 

 

STRONG COUPLING OF PHOSPHORESCENT PTOEP MOLECULES IN METALLIC MICROCAVITIES

Roli Verma, Tal Schwartz*
School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv,
6997801, Israel
*talschwartz@post.tau.ac.il
Strong coupling of organic molecules with optical microcavities can result in the formation of hybrid
light matter state, named polaritons, which may modify the molecular photophysical properties, as was
recently demonstrated [1,2]. Herein, we present strong coupling of triplet emitter platinum
octaethylporphyrines (PtOEP), where strong coupling may provide a novel mechanism for controlling
intersystem crossing. To realize these states, PtOEP molecules (doped into a PMMA host matrix,
~120nm thick layer) has been sandwiched nm between two silver mirrors which form an optical cavity.
Three absorption band of PtOEP molecule is shown in fig. 1(a) (black curve). The photoluminescence
properties of PtOEP molecules are also shown in fig. 1(a) where green curve and blue curve corresponds
to phosphorescence and fluorescence band respectively [3]. When the molecular Q-band excitation
(around 535nm) is coupled to the cavity, the formation of three polariton states is clearly seen in the
transmission (fig. 1b, black curve). Moreover, the photoluminescence in cavity (red curve in fig.1b)
matches with transmission of cavity. Moreover, the coupled system shows a typical polariton angleresolved
dispersion (inset in fig. 1b), proving that our system indeed operates in the strong coupling
regime, with a Rabi splitting energy of 104 meV between the upper and middle polariton branches, and
172meV between the middle and lower polariton branches. We expect that time-resolved spectroscopic
studies, which are currently underway, will reveal a modified intersystem crossing rate and modified
triplet occupation, with important applications in organic electronics and photochemical reactions.
Figure 1 (a) absorption (black solid), emission (green solid and blue solid) and Excitation (red solid) of bare molecule (b) cavity
transmission (black solid) and emission (red solid) and inset is the dispersion diagram of coupled system
1. J. A. Hutchison et al., Angew. Chem. Int. Ed. 51, 1592 (2012).
2. T. Schwartz et. al., ChemPhyChem 14, 125 (2013).
3. S. Kena-Cohen et. at., Phy. Rev. B, 075202 (2007).

 

 

 

Nano-Medicine

[24] THERMAL THERAPY WITH MAGNETIC NANO PARTICLES FOR CELL DESTRUCTION

 

Adi Vegerhof1, Menachem Motiei2, Arkady Rudintzky1, Rachela  Popovtzer3, Zeev Zalevsky1

 

 

1 Bar Ilan University; Bar Ilan University

 

 

2 Faculty of Engineering, Bar-Ilan University, Ramat-Gan, Israel; Institutes of Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan, Israel

 

 

3 Faculty of Engineering, Bar-Ilan University; The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University

 

 

 

Thermal therapy with magnetic Nano Particles for cell destruction

Adi Vegerhof 1, Menachem Motei1, Arkady Rudinzky1, Zeev Zalevsky1 and Rachela Popovtzer1

 

1Faculty of Engineering & the Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, Israel

 

Abstract

The main goal of this study involves developing a new concept for cell destruction based upon manipulating magnetic nano-particles (MNPs) along with illuminating a focused laser beam on the sample for its heating. Photo-thermal therapy (PTT) is a minimally-invasive therapy in which photon energy is converted into heat to destruct cells of malignant tissue. The manipulated MNPs technique that we present in this paper is realized by applying external magnetic excitation fields that oscillate the particles while the laser beam causes their temperature rising.  Laser heating combined with the additional MNPs motion causes to the heating of the cell culture to be more efficient and quicker, thereby it is making the manipulated MNPs technique as a superior agent for PTT.

Our method can specifically target cells or other live tissue, while herein we used head and neck cancer cells and formed a concentrated assembly yielding the improved cell destruction capabilities that our concept can offer.

Keywords: Magnetic nanoparticles (MNPs), thermotherapy, Photo-thermal therapy, head and neck cancer, cell destruction.

 

 

 

[29] TARGETED DRUG DELIVERY OF NEAR IR FLUORESCENT AND DOXORUBICIN-CONJUGATED POLY(ETHYLENE GLYCOL) BISPHOSPHONATE NANOPARTICLES FOR DIAGNOSIS AND THERAPY OF BONE TUMOR IN A MOUSE MODEL

 

Safra Rudnick-Glick1, Enav Corem Salkmon2, Igor Grinberg3, shlomo Margel4

 

 

1 Department of Chemistry ; The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University,

 

 

2 Department of Chemistry, Bar-Ilan Institute of Nanotechnology and Advanced Materials, Ramat-Gan, Israel; Institue of Nanotechnology and Advanced Matireals

 

 

3 Department of Chemistry; The Institute of Nanotechnology and Advanced Materials

 

 

4 Biu; Department of Chemistry & The Institute of Nanotechnology and Advanced Materials

 

 

 

Abstract

Osteosarcoma is a commonly diagnosed bone tumor. Current treatment based on a combination of surgery and chemotherapy is associated with severe side effects due to high dosages and nonspecific uptake. Bisphosphonates have a strong affinity to Ca+2 ions and are widely used in the treatment of bone disorders. We have engineered a unique biodegradable bisphosphonate nanoparticles baring two functional surface groups: 1) primary amine groups for covalent attachment of a dye/drug (e.g. NIR dye Cy 7 or doxorubicin); 2) bisphosphonates groups for targeting and chelation to bone hydroxyapatite. In vitro experiments on Saos-2 human osteosarcoma cell line, demonstrated that at a tenth of the concentration doxorubicin-conjugated bisphosphonate nanoparticles achieved a similar uptake to free doxorubicin. In vivo Soas-2 human osteosarcoma xenograft mouse models experiments confirmed specific targeting by the NIR fluorescence bisphosphonate nanoparticles, and 40% greater inhibition of tumor growth by doxorubicin-conjugated bisphosphonate nanoparticle over free doxorubicin.

 

 

 

[30] ENGINEERING OF BASIC PROTEINOIDS & PROTEINOIDS-PLLA POLYMERS AND HOLLOW NANOPARTICLES FOR BIOMEDICAL APPLICATIONS

 

Stella Kiel1, Enav Corem Salkmon2, Igor Grinberg3, Michal Kolitz Domb4, shlomo Margel5

 

 

1 Bar Ilan University; Bar Ilan University

 

 

2 Department of Chemistry, Bar-Ilan Institute of Nanotechnology and Advanced Materials, Ramat-Gan, Israel; Institue of Nanotechnology and Advanced Matireals

 

 

3 Chemestry Department; Institute for Nanotechnology and Advanced Materials (Bina)

 

 

4 Chemistry Department; Institute for Nanotechnology and Advanced Materials (Bina)

 

 

5 Biu; Department of Chemistry & The Institute of Nanotechnology and Advanced Materials

 

 

 

This research deals with the unique class of protein-like polymers, called “proteinoids”. Proteinoids are thermal polymers synthesized by the method of condensation polymerization of α-amino acids. Most of the reported proteinoids are composed of a various selected amino acids, so that the final product resembles natural proteins, thus providing non-immunogenic and non-toxic characteristics. It was also observed that proteinoids are far more resistant to cleavage by digestive enzymes than natural proteins. The proteinoids may be acidic, basic or neutral, depending on the composition of polymerized α-amino acids. The synthetic proteinoids may have an enormous number of applications and could be a source for preparing proteinoid hollow microspheres via a self-assembly process, for use in encapsulation and controlled release, drug delivery, etc.

Here we present a new set of basic proteinoids and proteinoid nano/micro-hollow particles containing a fluorescent dye and/or a cancer drug for biomedical applications. We prepared and characterized a new set of basic proteinoids by thermal random condensation polymerization of lysine with phenylalanine, histidine and arginine in the presence or absence of poly-L-lactic acid (PLLA 2 kDa). The PLLA was inserted into the main backbone polymeric chains and provided additional way for biodegradation of the proteinoid polymers. In our study we have demonstrated that Doxorubicin (DOX)-encapsulated proteinoid particles penetrated different types of cancer cells and were found to be toxic to cancer cells in 24 h post-treatment.

Our next goal is to produce nano-sized proteinoid reactors, which may combine drugs, imaging reagents with a covalently bonded therapeutic delivery system. Furthermore, since the particles possess functional groups, they may be conjugated to targeting moieties. The obtained bioactive nanosystems can serve in various biomedical applications.

 

 

 

 

[32] BIODEGRADABLE BISPHOSPHONATE NANOPARTICLES FOR IMAGING AND THERAPEUTIC APPLICATIONS IN OSTEOSARCOMA

 

Enav Corem Salkmon1, Safra Rudnick-Glick2, Igor Grinberg3, shlomo Margel4

 

 

1 Department of Chemistry, Bar-Ilan Institute of Nanotechnology and Advanced Materials, Ramat-Gan, Israel; Institue of Nanotechnology and Advanced Matireals

 

 

2 Department of Chemistry ; The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University,

 

 

3 Chemestry Department; Institute for Nanotechnology and Advanced Materials (Bina)

 

 

4 Biu; Department of Chemistry & The Institute of Nanotechnology and Advanced Materials

 

 

 

Abstract

Osteosarcoma (OS) is amongst the most commonly diagnosed bone tumors occurring in adolescence, young adults and adults over the age of 65. Current treatment is based on a combination of surgery and chemotherapy. Chemotherapy has improved the survival rate, however it is associated with severe side effects due to the use of high dosages, nonspecific uptake and poor bone blood supply. At present bisphosphonates (BP) are widely used in the treatment of bone disorders including OS. We have engineered a unique biodegradable BP nanoparticle that possesses a dual functionality: 1) covalent attachment of a dye (e.g., NIR dye) or drug to the nanoparticles through the primary amine groups on the surface of the nanoparticle; 2) chelation to the bone mineral hydroxyapatite through the BP on the surface of the nanoparticle. Due to a high concentration of PEG in the BP nanoparticles they possess a relatively long plasma half-life time. Therefore, the nanoparticle has potential for use both in diagnosis and therapy of OS. Doxorubicin was conjugated to the free amine on the surface of the BP nanoparticles. In vitro experiments on osteosarcoma cells demonstrated that the doxorubicin-conjugated BP nanoparticles possess a higher efficacy than the free doxorubicin. Further investigation in vivo in a chicken embryo model confirmed that the doxorubicin-conjugated nanoparticle was significantly more effective in inhibiting tumor growth compared to free doxorubicin at a similar concentration. Additionally, we have shown that these BP nanoparticles preferentially target OS tumor tissue, thus increasing anti-cancer drug bioavailability at targeted site.

 

 

 

[33] NEAR IR FLUORESCENT CONJUGATED POLY(ETHYLENE GLYCOL)BISPHOSPHONATE NANOPARTICLES FOR IN VIVO BONE TARGETING IN A CHICKEN EMBRYO AND A YOUNG MOUSE MODELS

 

Igor Grinberg1, Enav Corem Salkmon2, Safra Rudnick-Glick3, Eran Gluz4, shlomo Margel5

 

 

1 Chemestry Department; Institute for Nanotechnology and Advanced Materials (Bina)

 

 

2 Department of Chemistry, Bar-Ilan Institute of Nanotechnology and Advanced Materials, Ramat-Gan, Israel; Institue of Nanotechnology and Advanced Matireals

 

 

3 Department of Chemistry ; The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University,

 

 

4 Department of Chemistry, The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel.; The Institute of Nanotechnology and Advanced Materials

 

 

5 Biu; Department of Chemistry & The Institute of Nanotechnology and Advanced Materials

 

 

 

Abstract

Bisphosphonate (BP) compounds are widely used in the treatment of bone disorders. This group of drugs with a high affinity to Ca+2 ions is rapidly attracted to bone mineral, especially in areas of high resorption. We have engineered unique biodegradable BP nanoparticles (NPs) by dispersion co-polymerization of the monomers methacrylate-PEG-BP) and (3-Aminopropyl)mathacrylamide) with the crosslinker monomer tetra ethylene glycol diacrylate.  These NPs possess a dual functionality: 1) covalent attachment of a dye (e.g., near IR dye) or a drug to the nanoparticles through the primary amine groups on the surface of the NPs; 2) chelation to the bone mineral hydroxyapatite through the BP on the surface of the NPs. This study describes the uptake of the unique near IR fluorescent Cy 7-conjugated BP NPs in bone of a chicken embryo model as well as in a young mouse model. Blood half-life studies revealed a relatively long half-life, due to a high concentration of PEG in the BP NPs as well as a relatively long whole body clearance. Body distribution studies showed a specific uptake of the BP NPs in bone. These unique engineered BP NPs are planned to be utilized in future work for diagnostic and drug delivery systems that are targeted to bone disorders.

 

 

 

[40] ENGINEERING OF NOVEL PROTEINOIDS AND PLLA-PROTEINOID POLYMERS OF NARROW SIZE DISTRIBUTION AND UNIFORM NANO/MICRO-HOLLOW PARTICLES FOR BIOMEDICAL APPLICATIONS

 

Michal Kolitz Domb1, Enav Corem Salkmon2, Igor Grinberg3, shlomo Margel4

 

 

1 Chemistry Department; Institute for Nanotechnology and Advanced Materials (Bina)

 

 

2 Department of Chemistry, Bar-Ilan Institute of Nanotechnology and Advanced Materials, Ramat-Gan, Israel; Institue of Nanotechnology and Advanced Matireals

 

 

3 Chemestry Department; Institute for Nanotechnology and Advanced Materials (Bina)

 

 

4 Biu; Department of Chemistry & The Institute of Nanotechnology and Advanced Materials

 

 

 

The use of near-infrared (NIR) fluorescence imaging has gained great interest in the field of cancer detection due to the low autofluorescence that water and intrinsic biomolecules display in this region. The study describes the synthesis of new protein-like thermal polymers, proteinoids. Several types of proteinoids made of one to three different amino acids, in absence or presence, of low molecular weight PLLA, were synthesized. The ability to obtain several high-MW durable proteinoids, by using different amino acids, along with incorporating PLLA in their structure, yields a new perspective of biodegradable polymers and polymer nano/microparticles. The proteinoids reported are of unusual high molecular weights, along with a low polydispersity index. Under suitable gentle conditions, the proteinoids can self-assemble to form nano- and micron-sized hollow particles of relatively narrow size distribution. The proteinoid particles are non-toxic and stable; hence, they may be excellent candidates for various biomedical applications, e.g., cell labeling and separation, encapsulation, controlled release, drug targeting, etc. In this study, the proteinoid poly(glutamic acid-phenylalanine)-PLLA (P(EF)-PLLA) was used to form NIR fluorescent nanoparticles by encapsulation of the dye indocyanine green (ICG). The encapsulation process increases significantly the photostability of the dye. These NIR fluorescent nanoparticles were found to be stable and non-toxic. Leakage of the NIR dye from these nanoparticles into PBS containing 4% HSA was not detected. The NIR fluorescent nanoparticles were injected into a mouse and the biodistribution was monitored and quantified. Interestingly, the particles injected through the tail vein were found in various parts of the body, including the bones and brain, and were evacuated within 24 h completely. Tumor-targeting ligands such as peanut agglutinin (PNA) and anti-carcinoembryonic antigen antibodies (anti-CEA) were covalently conjugated to the NIR fluorescent P(EF-PLLA) nanoparticles’ surface, increasing thereby the fluorescent signal of tumors with upregulated corresponding receptors. Specific colon tumor detection by the NIR fluorescent P(EF-PLLA) nanoparticles was demonstrated in a chicken embryo model and a mouse model.

 

 

 

[62] SIZE CONTROLLED LAYER-BY-LAYER TECHNIQUE FOR DRUG DELIVERY

 

Lior Minkowicz1, Karen  Adler1, Ofra Benny1

 

 

1 The Hebrew University of Jerusalem; Institute for Drug Research

 

 

 

 

The ability of drugs to efficiently treat cancer is dependent on their stability and ability to penetrate tumor tissue. Drug delivery systems are designed to improve drugs’ properties such as stability and specificity, and provide a means for slow release. One of the main challenges in drug delivery in cancer is the ability to control the exact properties of drug vehicle. It was demonstrated that particle/carrier size, charge, and stiffness all have a substantial effect on the bio-distribution of drug carriers and on their tumor uptake.

Layer-by-layer (LbL) deposition on template beads represents an appealing method for controlling drug carrier properties. The majority of studies in this field use silica beads as template, requiring harsh conditions for melt-down that can damage drug loading. An alternative template material is calcium carbonate (CaCO3), but it has some significant drawbacks such as large heterogeneity due to polymorphism and difficulty in controlling size.

We hypothesize that controlling CaCO3 particle size and morphology can improve properties of LbL drug carriers and provide a versatile platform for preparing a drug loaded particle library with different charges, sizes, and flexibility. 

The crystallization of CaCO3 particles was performed by reacting sodium carbonate (Na₂CO₃) and calcium nitrate (Ca(NO₃)₂) in the presence of additives and under sonication. The particles were used as template for LbL deposition of oppositely charged fluorescently labeled polysaccharides, alginate and chitosan. The particles were visualized using fluorescent and confocal microscope. We demonstrated that the size of CaCO3 templates ranging from sub-micron to a few microns can be controlled by modifying preparation conditions. Moreover, by changing the number of layers, we can vary the multi-layering width affecting the overall diameter of the particles.

On-going research is being done to optimize properties of particles with anti-cancer drugs to investigate the potential increase in tumor selectivity by adjusting the carrier to optimize affinity and cellular uptake.

 

 

 

[63] NANOPARTICLE-BASED CT IMAGING FOR STEM CELLS TRACKING WITHIN THE BRAIN: APPLICATION IN NEUROPSYCHIATRIC DISORDERS

 

Oshra Betzer1, Amit Shwartz2, Menachem Motiei3, Gal Yadid4, Rachela  Popovtzer5

 

 

1 The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University; Gonda Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel

 

 

2 Everard and Mina Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel; Gonda Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel

 

 

3 Faculty of Engineering, Bar-Ilan University, Ramat-Gan, Israel; Institutes of Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan, Israel

 

 

4 Gonda Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel; Everard and Mina Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel

 

 

5 Faculty of Engineering, Bar-Ilan University; The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University

 

 

 

Nanoparticle-based CT imaging for stem cells tracking within the brain: application in neuropsychiatric disorders

 

A critical problem in the development and implementation of stem cell-based therapy is the lack of reliable, non-invasive means to image and trace the cells post-transplantation and evaluate their bio-distribution, final fate and functionality. In this study, we developed a gold nanoparticle-based CT imaging technique for longitudinal mesenchymal stem cell (MSC) tracking within the brain. We applied this technique for non-invasive monitoring of MSCs transplanted in a rat models for depression and drug addiction. Our research reveals that cell therapy is a potential approach for treating neuropsychiatric disorders. Our results, which demonstrate that cell migration could be detected as early as 24 hours and up to one month post-transplantation, revealed that MSCs specifically navigated and homed to distinct depression-or addiction related brain regions. We further developed a non-invasive quantitative CT ruler, which can be used to determine the number of cells residing in a specific brain region, without tissue destruction or animal scarification. This technique may have a transformative effect on cellular therapy, both for basic research and clinical applications.

 

 

 

[72] TUMOR NECROSIS FACTOR RELATED APOPTOSIS INDUCING LIGAND-CONJUGATED NEAR IR FLUORESCENT IRON OXIDE/HUMAN SERUM ALBUMIN CORE-SHELL NANOPARTICLES OF NARROW SIZE DISTRIBUTION FOR CANCER TARGETING AND THERAPY

 

Itay Levy1

 

 

1 Bar Ilan University; Biu

 

 

 

Tumor Necrosis Factor Related Apoptosis Inducing Ligand-Conjugated Near IR Fluorescent Iron Oxide/Human Serum Albumin Core-Shell Nanoparticles of Narrow Size Distribution for Cancer Targeting and Therapy

Itay Levy, Igor Grinberg, Benny Perlstein, Enav Corem-Salkmon and Shlomo Margel*.

Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel

*Corresponding author. E-mail: shlomo.margel@mail.biu.ac.il

 

Abstract

Although much progress has been made in the field of cancer therapy, cancer remains one of the leading causes of death in the western world. Here we have designed and studied a unique type of composite multi-functional near IR (NIR) fluorescent iron oxide (IO) nanoparticles (NPs) of narrow size distribution for tumor targeting and therapy. These NPs were prepared by nucleation followed by controlled growth of thin films of IO onto Cy7-conjugated gelatin nuclei, coated then with human serum albumin (HSA) by a thermal precipitation process.  The hydrodynamic diameter of these core-shell NPs could be easily controlled by varying the precipitation reaction temperature.

For targeting and an anti-cancer effect, we conjugated the Tumor Necrosis Factor Related Apoptosis Inducing Ligand (TRAIL) cytokine to the surface of the NIR fluorescent IO/HSA NPs via a polyethylene glycol (3 kDa) linker.  The conjugated TRAIL exhibited enhanced and prolonged anti-cancer activity in both human glioblastoma multiforme and colon cancer cell lines. Further, the combination of these IO/HSA-TRAIL NPs with the commonly used chemotherapeutic drug doxorubicin resulted in a synergistic anti-cancer effect on these cancer cell lines. In addition, we also clearly demonstrated by topically and IV administrations the specific targeting effect and the synergistic therapy effect of these NIR fluorescent NPs in-ovo, by using a chicken embryo model of tumors derived from the various human cancer cell lines.

 

Keywords:   Iron oxide nanoparticles, Near IR fluorescent iron oxide nanoparticles, Cancer targeting, Cancer therapy.

 

 

 

[117] NIR FLUORESCENT CORE AND CORE-SHELL ALBUMIN NANOPARTICLES FOR IN VIVO DETECTION OF COLONIC NEOPLASMS

 

Sarit Cohen1, shlomo Margel1

 

 

1 Biu; Department of Chemistry & The Institute of Nanotechnology and Advanced Materials

 

 

 

 

NIR Fluorescent Core and Core-Shell Albumin Nanoparticles for In vivo Detection of Colonic Neoplasms

 

According to scientific literature, near IR (NIR) dyes such as Indocyanine Green (ICG) and other structurally related cyanine dyes have been shown to have high affinity to albumin (HSA, BSA). We have exploited this fact for the preparation of albumin nanoparticles containing cyanine NIR dyes, entrapped by strong non-covalent interactions. This study demonstrates that the encapsulation of NIR fluorescent dye within the albumin nanoparticles significantly reduces the photobleaching of the dye. Leakage of the NIR dye from these nanoparticles into PBS containing 4% albumin and into human bowel juice was not detected. The particles may also be of core-shell structure, e.g., a core such as iron oxide with the NIR-dyed albumin coating thus forming the shell. The work presented here is a feasibility study to test the suitability of NIR fluorescent HSA nanoparticles for optical detection of colonic cancer. The tumor-targeting ligands, peanut agglutinin

(PNA), anti-carcinoembryonic antigen antibodies (anti-CEA) and tumor associated glycoprotein-72 monoclonal antibodies (anti-TAG-72) were covalently conjugated to the NIR fluorescent HSA nanoparticles. Specific colon tumor detection was demonstrated in chicken-embryo and mouse models for both the non-conjugated and the biomolecule-conjugated NIR fluorescent albumin nanoparticles. The conjugation of the PNA, or anti- CEA or anti-TAG-72 to the nanoparticles significantly increased the fluorescence intensity of the tagged colon tumor tissues relative to the non-conjugated nanoparticles. The main advantage of these particles is their fluorescence in the NIR region of the electromagnetic spectrum, allowing in vivo imaging with low tissue absorbance, increased tissue penetration and low auto fluorescence of bodily tissues. This allows for early specific detection of neoplasms in the gastrointestinal tract. In future work we also plan to encapsulate cancer drugs, e.g., doxorubicin, within these NIR fluorescent nanoparticles for both colon cancer imaging and therapy

 

 

 

[121] NANOMEDICINE FOR CANCER IMMUNOTHERAPY:

 TRACKING CANCER-SPECIFIC T CELLS IN VIVO

 

Rinat Meir1

 

 

1 Bar Ilan University; The Institute for Nanotechnology Biu

 

 

 

NANOMEDICINE FOR CANCER IMMUNOTHERAPY: TRACKING CANCER-SPECIFIC T CELLS IN VIVO

Rinat Meir1, Katerina Shamalov2, Oshra Betzer1, Menachem Motiei1, Cyrille Cohen2, Rachela Popovtzer1

1 Faculty of Engineering, Bar-Ilan University, Ramat-Gan, Israel
2 Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel

 

Application of immune cell-based therapy in routine clinical practice is challenging, due to the poorly-understood mechanisms underlying success or failure of treatment. Development of accurate and quantitative imaging techniques for non-invasive cell tracking can provide essential knowledge for elucidating these mechanisms. We designed a novel method for longitudinal and quantitative in vivo cell tracking, based on the superior visualization abilities of classical X-ray computed tomography (CT), combined with state-of-the-art nanotechnology. Herein, T-cells were transduced to express a melanoma-specific T-cell receptor and then labeled with gold nanoparticles (GNPs) as a CT contrast agent. The GNP-labeled T-cells were injected intravenously to mice bearing human melanoma xenografts, and whole-body CT imaging allowed examination of the distribution, migration and kinetics of T-cells. Using CT, we found that transduced T-cells accumulated at the tumor site, as opposed to non-transduced cells. Labeling with gold nanoparticles did not affect T-cell function, as demonstrated both in vitro, by cytokine release and proliferation assays, and in vivo, as tumor regression was observed. Moreover, to validate the accuracy and reliability of the proposed cell tracking technique, T-cells were labeled both with green fluorescent protein for fluorescence imaging, and with GNPs for CT imaging. A remarkable correlation in signal intensity at the tumor site was observed between the two imaging modalities, at all time points examined, providing evidence for the accuracy of our CT cell tracking abilities. This new method for cell tracking with CT offers a valuable tool for research, and more importantly for clinical applications, to study the fate of immune cells in cancer immunotherapy.

 

 

 

[122] RED BLOOD CELLS AS A TOOL FOR TESTING OF NANOPARTICLES BIOACTIVITY

 

Gregory Barshtein1, Saul Yedgar1, Leonid D Shvartsman2

 

 

1 The Faculty of Medicine; Campus Een Cerem

 

 

2 The Racah Institution of Physics; Campus Givat Ram

 

 

 

 

 

 

Engineered man-made NPs have various applications in biomedical fields for improving diagnostic tools, drug delivery and cancer treatment. Independently from their use, source and exposure, NPs eventually enter the bloodstream. The entrance of NPs to bloodstream leads to their interaction with red blood cells (RBC), a central object in the blood circulation. This interaction of NPs with RBC may cause impairment of RBCs functionality, specifically, their hemolysis.

Hemolysis may occur if the integrity of RBCs membrane is broken and hemoglobin is released, which may lead to an adverse health effects (e.g., anemia, hypertension, renal toxicity). Thus, hemolytic activity of NPs have been suggested as key tests in determining the safety of NPs. Although hemolysis tests have been conducted with various NPs, comparing results across studies are difficult due to variability in the protocols for performing particle characterization and hemolysis testing. It is necessary to emphasize that according to all previously used protocols, the interaction between NPs and RBC was examined in static conditions. 

In the presented research, we tested the role of shear stress application on hemolytic activity of NPs.

For examination of presented hypothesis we studied interaction between polystyrene NPs (PS-NPs) and RBCs under flow-induced shear stress. We examined the role of following two factors on the level NPs-induced hemolysis: protein-corona formation and application of high shear stress. We demonstrated that shear stress application accelerated NPs-induced hemolysis.

The research characterize, for the first time, the role of the shear stress application in NPs-induced hemolysis. This knowledge will aid our understanding of the NPs toxicity. Finally, the fruits of this research could lead to novel applications in the field of nanomedicine – development of a new methodology for the assessment of potential toxicity of nanoparticles.

 

 

 

[127] IMPROVED ORAL ABSORPTION OF EXENATIDE USING AN ORIGINAL NANOENCAPSULATION AND MICROENCAPSULATION APPROACH

 

Liat Soudry-kochavi1, Natalya  Naraykin1, Taher Nassar1, Simon Benita1

 

 

1 The Institute of Drug Research ; The Hebrew University of Jerusalem, Ein Karem

 

 

 

Oral delivery is the most convenient and favorable route for chronic administration of peptides and proteins to patients. However, many obstacles are faced when developing such a delivery route. Nanoparticles (NPs) are among the leading innovative solutions for delivery of these drugs. Exenatide is a peptidic drug administered subcutaneously twice a day chronically as an add-on therapy for the world wide pandemic disease, diabetes. Many attempts to develop oral nanocarriers for this drug have been unsuccessful due to the inability to retain this hydrophilic macromolecule under sink conditions or to find a suitable cross-linker which does not harm the chemical integrity of the peptide. In this study, we report about an original oral delivery solution based on a mixture of albumin and dextran NPs cross-linked using sodium trimetaphosphate. Moreover, we suggest a second defense line of gastro-resistant microparticles composed of an appropriate ratio of Eudragit® L100-55 and hydroxypropylmethylcellulose, for additional protection to these NPs presumably allowing them to be absorbed in the intestine intact. Our results demonstrate that such a system indeed improves the relative oral bioavailability of exenatide to a level of about 77% compared to subcutaneous injection due to the presence of dextran in the coating wall of the NPs which apparently promotes the lymphatic uptake in the enterocytes. This technology may be a milestone on the way to deliver other peptides and proteins orally.

 

 

 

[156] THERAPEUTIC EFFICACY OF COMBINING PEGYLATED LIPOSOMALDOXORUBICIN AND RADIOFREQUENCY (RF) ABLATION:COMPARISON BETWEEN SLOW-DRUG-RELEASING,NON-THERMOSENSITIVE AND FAST-DRUG-RELEASING,THERMOSENSITIVE NANO-LIPOSOMES

 

Alexander  V. Andriyanov1

 

 

1 Laboratory of Liposome and Membrane Research; Imric

 

 

 

Aims: To determine how the accumulation of drug in mice bearing an extra-hepatic tumor and its therapeutic efficacy areaffected by the type of PEGylated liposomal doxorubicin used, treatment modality, and rate of drug release from the

liposomes, when combined with radiofrequency (RF) ablation.

Materials and Methods: Two nano-drugs, both long-circulating PEGylated doxorubicin liposomes, were formulated: (1) PEGylated doxorubicin in thermosensitive liposomes (PLDTS), having a burst-type fast drug release above the liposomes’ solid ordered to liquid disordered phase transition (at 42uC), and (2) non-thermosensitive PEGylated doxorubicin liposomes (PLDs), having a slow and continuous drug release. Both were administered intravenously at 8 mg/kg doxorubicin dose to tumor-bearing mice. Animals were divided into 6 groups: no treatment, PLD, RF, RF+PLD, PLDTS, and PLDTS+RF, for intratumor doxorubicin deposition at 1, 24, and 72 h post-injection (in total 41, mice), and 31 mice were used for randomized survival studies.

Results: Non-thermosensitive PLD combined with RF had the least tumor growth and the best end-point survival, better than PLDTS+RF (p,0.005) or all individual therapies (p,0.001). Although at 1 h post-treatment the greatest amount of intra-tumoral doxorubicin was seen following PLDTS+RF (p,0.05), by 24 and 72 h the greatest doxorubicin amount was seen for PLD+RF (p,0.05); in this group the tumor also has the longest exposure to doxorubicin.

Conclusion: Optimizing therapeutic efficacy of PLD requires a better understanding of the relationship between the effect of RF on tumor microenvironment and liposome drug release profile. If drug release is too fast, the benefit of changing the microenvironment by RF on tumor drug localization and therapeutic efficacy may be much smaller than for PLDs having slow and temperature-independent drug release. Thus the much longer circulation time of doxorubicin from PLD than from PLDTS may be beneficial in many therapeutic instances, especially in extra-hepatic tumors.

 

 

 

[184] MICROFLUIDIC BASED FABRICATING OF  NANOPARTICLES

 

Ben-Zion Amoyav1, Ofra Benny2

 

 

1 Hebrew University; Idr- Institute Drug Reserch

 

 

2 The Hebrew University of Jerusalem; Institute for Drug Research

 

 

 

Microfluidic based Fabricating of  nanoparticles:

Microfluidics is the science of fluid flows at the microscopic scale. Small volumes of solvent, sample, and reagents flowing through micro-channels embedded in the chip, providing a whole new world of improved powerful platform for physical and biological assays.

Miniaturizing into a microfluidic device offer many advantages, among others small requirements for solvents and reagents, low cost and faster parallel analysis.

 

One of the projects we are focusing at the lab is trying to develop new techniques with these useful microdevices templates and overcome a central challenge in the development of new modern anti-cancer drugs nowadays – synthesis of monodisperse nanoparticles.

PLGA poly(lactic-co-glycolic acid) has attracted considerable attention due to its attractive biodegradability property and its one of the most successfully developed nano-particles.

To synthesize particles with this process, we used two different types of microfluidic chips (T Junction and Focused flow) that able to create PLGA emulsions with a highly controlled structure and uniform droplets, which are then solidified to produce particles. 

By varying flow rates, polymer concentration and polymer type we are able to optimize the size, decrease polydispersity index, and as a result to improve the PK and PD characteristics.

The Microfluidics may find applications for modern development and optimization of polymeric nanoparticles in the newly emerging field of nanomedicine

 

 

 

[185] ORAL ABSORPTION OF SOLIDIFIED POLYMER NANOMICELLES

 

Adi Karsch-Bluman1, Eva Abramov2, Ouri Schwob1, Mara Shapiro1, Ofra Benny3

 

 

1 School of Pharmacy; Hebrew University

 

 

2 The Hebrew University of Jerusalem; School of Pharmacy

 

 

3 The Hebrew University of Jerusalem; Institute for Drug Research

 

 

 

Oral absorption of solidified polymer nanomicelles

Oral delivery of poorly soluble drugs represents a significant challenge in drug development. Oral administration is the preferable route of drug delivery, especially in chronic disease,that requires prolonged treatments. However, the gastrointestinal track presents a significant physiological barrier for drugs with its wide range of pH and enzymatic activity. Encapsulation of drugs may help this problem by increasing drug absorption, protecting drugs from the external milieu, and providing a controlled release.

Our previous studies demonstrated that conjugation of lipophilic drugs to short polymer monomethoxy poly lactic acid polyethylene glycol (mPEG-PLA) improved drug solubility, stability and oral availability. Here we present our recent results characterizing mPEG-PLA nanomicelles (~20nm) as a vehicle for oral delivery of encapsulated compounds (without chemical conjugation).

To study the intestinal absorption of solid nanomicelles, we used the Caco-2 permeability assay. Caco-2 are human epithelial colorectal adenocarcinoma cells which are used as a standard cellular model for studying oral availability of drugs. In order to elucidate the molecular mechanism of mPEG-PLA nanomicelle endocytosis in Caco-2 cells, specific inhibitors of clathrin, caveolae and lipid raft mediated endocytosis were used. mPEG-PLA nanomicelles were found to internalize rapidly, in a 30 min initial kinetics, with an Apical to Basolateral apparent permeability coefficient (Papp) of 3.8 x10-6 cm/s (2 hr) and 5×10-6 cm/s (4 hr). Moreover, endocytosis was found to be mediated by clathrin in an energy-dependent manner. Finally, we found that the low-density lipoprotein (LDL) receptor is directly involved in the endocytosis of mPEG-PLA, as indicated by interruption in internalization after blockage of the receptor by anti-LDLR antibody and by siRNA knockdown of LDLR gene. Our results introduce mPEG-PLA nanomicelles as a platform for oral delivery of poorly absorbed drugs.

 

 

 

 

[219] MODIFIED STARCH BASED NANOPARTICLES AS PIP3 DELIVERY SYSTEM FOR WOUND HEALING

 

ETILI HOLLANDER1, ramesh Chintakunta2, Riki Goldbart3, Tamar  Traitel3, Assaf Rudich4, Joseph Kost3

 

 

1 Ben Gurion University OF THE Negev; Ben Gurion University OF THE Negev

 

 

2 Ben Gurion University OF THE Negev; –

 

 

3 Ben Gurion University of the Negev; Department of Chemical Engineering

 

 

4 Faculty of Health Sciences; Department of Clinical Biochemistry

 

 

 

Modified Starch Based Nanoparticles as PIP3 Delivery System for Wound Healing

Etili Hollander1, Ramesh Chintakunta1, Riki Goldbart1, Tamar Traitel1, Assaf Rudich2, Joseph Kost1

1Department of Chemical Engineering; 2Department of Clinical Biochemistry, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel

Wound healing is a natural restorative response to tissue injury. The primary function of the skin is to serve as a protective barrier against the environment. Once the protective barrier is broken, as a result of an injury, the normal process of wound healing is immediately set in motion. 1

Phosphatidylinositol-3,4,5-trisphosphate (PIP3), is a phosphorylated phospha- tidylinositol with phosphate moiety on positions 3,4 and 5 of the inositol ring. PIP3 is a negatively charged, required lipid messenger that plays an important role in the regulation of many cellular processes, including proliferation, survival, migration and wound healing. 2

To heal a wound, cells surrounding the wound must survive, proliferate, migrate and directionally grow to close the wound.

One of the main challenges is creating an effective path for delivering negatively charged PIP3 into keratinocytes. Starch is a natural polysaccharide that is considered advantageous for drug delivery due to its biodegradability, biocompatibility, low immunogenicity and minimal cytotoxicity. 3 In this study, we use modified cationic starch (Q-Starch) as a PIP3 carrier.

The positively charged Q-starch and the negatively charged PIP3 interact electrostatically, to form a complex. PIP3/Q-Starch complexes’ surface charge, radius and morphology were evaluated by zeta potential, Dynamic Light Scattering (DLS) and cryo-TEM in the range of 1.5-3 molar ratio of Q-Starch nitrogen groups and PIP3 phosphate groups (N/P ratio). Results show that average surface charge increases with the increase of N/P ratio. The complexes were successfully obtained above 1.5 N/P ratio.

 

1 Martin, et al. 1997, Science, 276, 75-81.

2 Leslie, et al. 2007, Curr Biol. 17, 115–125.

3 Amar-Lewis, Eliz, et al. 2014, Journal of Controlled Release 185, 109-120.

 

 

 

[238] EXPLORING THE TRANSPORT MECHANISM OF RNAI AND QUATERNIZED-STARCH BASED NANOPARTICLES FOR REDUCING MULTIDRUG RESISTANCE IN OVARIAN CANCER CELLS

 

Eliz Lewis1, Limor Cohen2, Riki Goldbart3, Tamar  Traitel3, Levi A. Gheber2, Joseph Kost3

 

 

1 Ilse Katz Institute for Nanoscale Science and Technology; Department of Chemical Engineering

 

 

2 Ilse Katz Institute for Nanoscale Science and Technology; Department of Biotechnology Engineering

 

 

3 Ben Gurion University of the Negev; Department of Chemical Engineering

 

 

 

Drug resistance in ovarian cancer cells is inherited due to over expression of the multi drug efflux pump, P-glycoprotein (P-gp), which effectively reduces the concentration of anti-cancer drugs in the cells. We propose RNA interference (RNAi) approach to silence P-gp expression and induce sensitivity to chemotherapeutic drugs; however a major challenge is a successful siRNA delivery into the cancer cells and its release in the cytoplasm. Therefore, our goal is to develop a delivery platform that will allow overcoming siRNA delivery barriers. We have presented before a safe (biodegradable and biocompatible) and efficient carrier for siRNA based on modified potato starch with quaternary amine groups (Q-starch). Q-starch in the presence of siRNA undergoes self-assembly formation of Q-starch/siRNA nanoparticles and ovarian cancer cells transfected with Q-starch/siP-gp (downregulate P-gp) showed reduced expression of P-gp (50% reduction).

This study examines the nanoparticle’s cellular transport mechanism and its main barriers, cellular uptake and endosomal escape, using light-microscopy and biophysical approaches.

We demonstrated that the nanoparticles rapidly adhere to the cell surface and already following 15min of application accumulate in the cells. Using live-cell microscopy, by tracking nanoparticles’ mean square displacement, we showed significant changes in the dynamics of the nanoparticles in time. The uptake stage is presented by a kinetic study qualitatively and quantitatively showing that Q-starch is necessary for the internalization of siRNA. We elucidated the mechanism by which the nanoparticles enter the cells and revealed a dynamine-dependent endocytosis and partial dependency on clathrin-mediated mechanism. In correspondence, we have shown the following intracellular transport of the complexes through early endosomes (rab5a) up to 4hr, late endosomes (rab7a) and lysosomes following 24hr. Finally, we suggest that a fraction of the complexes are rendered by the endosomal escape barrier in delivering RNAi to the cell cytoplasm. Thus, we suggest in our future study to increase endosomal escape by additional chemical modifications of Q-starch that will promote efficiency of gene silencing.

 

 

 

[251] QUATERNIZED STARCH NANOPARTICLES FOR EXOGENOUS PI3P DELIVERY

 

Nitzan Marelly1, Tali Vodonos2, ramesh chintakunta1, Riki Goldbart1, Tamar  Traitel1, Assaf Rudich2, Joseph Kost3

 

 

1 Ben Gurion University of the Negev; Department of Chemical Engineering

 

 

2 Faculty of Health Sciences; Department of Clinical Biochemistry

 

 

3 Ben-Gurion University; Department of Chemical Engineering

 

 

 

Quaternized starch nanoparticles for exogenous PI3P delivery

Nitzan Marelly1, Tali Vodonos2, Ramesh Chintakunta1, Riki Goldbart1, Tamar Traitel1, Assaf Rudich2, Joseph Kost1

1Department of Chemical Engineering; 2Department of Clinical Biochemistry, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel

 

Autophagy, an intra-cellular process in eukaryotic cells, allows for the digestion and recycling of cytoplasmic contents. This is achieved through the formation of double-membrane vesicles (autophagosomes) that undergo degradation through fusion with lysosomes. Basal autophagy plays an important role in cellular homeostasis. Autophagy can also be induced as a cellular reaction to various situations, such as nutrient starvation or pathogen infection. Thus, dysfunction in autophagy has been implicated in the pathogenesis of various diseases, like cancer, infectious diseases and neurodegenerative disorders. For example, a decrease in autophagy flux is correlated with insulin resistance of hepatocytes in obesity. This may be solved by up-regulating autophagy flux.

Since PI3P mediates autophagosome biogenesis through membrane deformation and elongation, and therefore acts as an activator of autophagy, we decided to evaluate its exogenous delivery to the cells using modified starch as a carrier. A major obstacle in delivering exogenous PI3P into cells is overcoming its negative charge (derived from the phosphate groups on the inositol ring).

Starch, a natural polysaccharide, is considered advantageous for drug/gene delivery due to its biodegradability and biocompatibility. In this research potato starch was modified into cationic starch and was used as PI3P carrier. The positively charged quaternized ammonium groups on the modified starch and the negatively charged PI3P interact electrostatically, allowing for self-assembly complexation.

        Q-starch/PI3P complexes were characterized (size, surface charge and geometry) at different N/P ratios (molar ratio between positive nitrogen groups on Q-starch (N) and negative phosphate groups on PI3P (P)). Complexes uptake and effect on autophagy was assessed on HEK-293 cells. Up-regulation of autophagy was shown, suggesting a potential approach for overcoming insulin resistance.

 

 

 

 

[260] TOPICAL TREATMENT OF PSORIASIS BY MIRNA DELIVERY BASED ON ULTRASOUND AND MODIFIED STARCH

 

Rinat Lifshiz1, Gali Lerman2, Einat Elharrar2, Tal Segman2, Riki Goldbart1, Tamar  Traitel3, Dror Avni2, Yehezkel Sidi2, Joseph Kost1

 

 

1 Ben-Gurion University; Department of Chemical Engineering

 

 

2 Laboratory of Molecular Cell Biology, Center for Cancer Research and Department of Internal Medicine; Tel Hashomer

 

 

3 Ben Gurion University of the Negev; Department of Chemical Engineering

 

 

 

 

     Psoriasis is a chronic inflammatory skin disease that affects 3% of the population, yet it is still without a cure. The most advanced drugs developed in recent years for psoriasis are systemic interventions aimed to inhibit one of the major cytokines which play important roles in the pathogenesis of the psoriatic inflammation. All of these agents are immunosuppressive and indicated only in patients with severe psoriasis or psoriatic arthritis, while safe and effective topical therapy, needed in most of the psoriatic patients, is still lacking. Lerman et al discovered specific micro-RNAs (miRNAs), which are silenced in the psoriatic epidermis and can down-regulate the expression of IL-22RA1 and IL-17RA two subunits of the receptors  to IL-22 and IL-17A respectively. Although miRNA offers new therapeutic potential for treating psoriasis, its topical delivery to the depth of the epidermis is challenging. There are several barriers to topical delivery of miRNAs: 1. The barrier properties of the top layer of the epidermis (stratum corneum): 2. Naked miRNA is unstable in vivo due to enzymatic degradation and immunological responses. 3. The efficacy of RNAi that penetrates the epidermis, is further limited by poor cellular uptake. To overcome these obstacles and allow topical delivery of miRNA to skin cells, we suggested the use of ultrasound (US) as a mean to enhance biological membrane and skin permeability, and quaternized starch (Q-starch) as an miRNA delivery carrier. In vivo experiments on humanized psoriatic mouse model verified the ability of US and modified starch carrier to enhance miRNA transdermal delivery, as well as subsequent decrease in the expression of the IL-22RA1 and IL-17RA, the miRNA target proteins. Moreover, a significant decrease in the psoriatic inflammatory markers has been visualized.

Our results suggest that ultrasound and the Q-starch carrier assisted topical delivery of miRNA could pave the way for future miRNA-based therapy.

 

 

 

[304] 3-D MULTI-CELLULAR MODEL FOR DRUG DELIVERY

 

Hila Shoval1, Ouri Schwob2, Ofra Benny3

 

 

1 The Hebrew University; Institue for Drug Research

 

 

2 School of Pharmacy; Hebrew University

 

 

3 The Hebrew University of Jerusalem; Institute for Drug Research

 

 

 

3-D multi-cellular model for Drug Delivery

Hila Shoval,Ouri Schwob,Ofra Benny

Studying nanoparticle uptake in cells is being predominantly performed in monolayer cultured cells. However, the monolayer lack the presentation of complex cell-cell interactions and extra-cellular matrix. As a result, while the two-dimensional cellular models may be good for determine mechanism of nanoparticle uptake and kinetics of cellular interactions at the single cell level, they cannot provide information about transport of nanoparticles in tissues.

Our goalis to develop a tissue-like 3-D cellular models, which contain more components of the tumor microenvironment, to provide a prediction for the potential of drug nano-carriers to access into tissues.

            Cancer multicellular spheroids were grown from different tumor cell types and characterized to be used as a model for nanoparticle penetration in 3- dimension. Fluorescent-labeled Polyethylene glycol-Poly lactic acid (mPEG-PLA) polymer nanoparticles (~20 nm) were fabricated and characterized. The micelles were incubated with tumor spheroids and the kinetics of their “tissue” diffusion was determined by detecting the fluorescence inside spheroids. Our results indicated a time-dependent penetration of PEG-PLA nanoparticles into the spheroids cell layers. Moreover, we found that this model can differentiate between different tumor types according to the kinetic of nanoparticle transport. We concluded that multicellular spheroid can be used as an efficient model for nanoparticle interaction in tissues and our follow-up studies will compare our results to in-vivo.

 

Kay words: spheroids, tumor, micelles, PEG-PLA

 

 

 

 

 

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[308] ANIONIC NANOPARTICLES OF ALGS–CA2+-SIRNA ARE EFFICIENT CARRIERS OF SIRNA TO HUMAN HEPATOCYTE CELL LINE

 

Efrat Korin1, Olga  Kryukov1, Smadar  Cohen2

 

 

1 Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev; Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev

 

 

2 Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev; Regenerative Medicine and Stem Cell (Rmsc) Research Center and 2the Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel

 

 

 

Anionic nanoparticles of AlgS–Ca2+-siRNA are efficient carriers of siRNA to human hepatocyte cell line.

 

Efrat Korin1, Olga Kryukov1, Smadar Cohen1,2, 3

 

1Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, 2Regenerative Medicine and Stem Cell (RMSC) Research Center and 3The Ilse Katz Institute for Nanoscale Science and Technology,  Ben-Gurion University of the Negev, Beer-Sheva, Israel.

 

Over the past decade, small interfering RNA (siRNA) has intensively been explored owing to its potential in disease therapy. Yet, siRNA delivery in vivo is still a major challenge due to its rapid degradation by nucleases, poor cellular uptake and rapid renal clearance following systemic administration. Thus, it is critical to develop an appropriate delivery system that will overcome these limitations and to improve the safety of potential RNAi-based therapeutics. We developed a novel siRNA delivery platform, based on the complexation of Alginate sulfate (AlgS) with siRNA, mediated by calcium ions bridges. Realizing the potential toxicity of cationic carriers, the AlgS–Ca2+-siRNA nanoparticles (AlgS-NPs) have a net negative surface charge of ~-8 mV. The chemical interaction between the three components constituting the AlgS-NPs was confirmed by XPS and TEM. Assessing the cellular uptake of AlgS-NPs in human hepatocyte cell line (HEPG2) by imaging flow cytometry analysis revealed a highly efficient uptake, resulting in siRNA internalization in 89% of cells. Furthermore, results obtained by quantitative Real-Time PCR (qPCR) showed the silencing of the STAT3 gene to an extent of 90% without being cytotoxic to cells. In summary, the results obtained so far, indicate that AlgS-NPs may offer a promising platform for efficient delivery of therapeutic siRNA.

 

 

 

 

 

[320] MODIFIED PECTIC GALACTAN CARRIER FOR GENE THERAPY DEMONSTRATED SIGNIFICANT CELLULAR UPTAKE IN VITRO

 

Nitsa Buaron1, ramesh chintakunta1, Tamar  Traitel1, Riki Goldbart1, Henry Brem2, Joseph Kost1

 

 

1 Ben Gurion University of the Negev; Department of Chemical Engineering

 

 

2 Johns Hopkins Medical Institutions ; Neurosurgery

 

 

 

 

                Brain tumors represent one of the most malignant forms of human cancers, where the most common and aggressive is the glioma. We explored a novel gene therapy approach based on natural polysaccharides for targeted delivery to cancerous cells. Galectin-3 is a cell protein that carries an active carbohydrate recognition domain (CRD) for β-galactoside sugars that is highly expressed in a variety of cancer cells, such as glioma. Since the natural polysaccharide pectin has galactose-rich side chains (galactans), it can be utilized as a carrier for delivering genes to glioma cells in a targeted manner, based on the highly specific carbohydrate interaction between galactan and galectin-3 receptors on the cell membrane. Moreover, pectin has been proven to be effective in inhibiting or blocking cancer cell aggregation, adhesion, and metastasis. Since pectin is a natural polysaccharide, it carries further advantages as a gene delivery carrier over the currently available synthetic ones, such as biodegradability, biocompatibility, low immunogenicity, and minimal cytotoxicity.     

                Modified pectin-based carrier was synthesized and explored. Q-galactan was prepared by modifying quaternary ammonium groups (Q=N+(CH3)3) on pectic galactan. Q-galactan was successfully synthesized and characterized. A globular condensed complexation with plasmid DNA was clearly observed. Q-galactan was found to form complexes with size ranging from 80 nm to 120 nm, which is suitable for internalization to the cell through endocytosis. The complexes were successfully proven to be non-toxic to C6 rat glioma cells line. Investigation of cellular uptake and cellular path indicated the complexes were able to penetrate the cell membrane and approach the nucleus within 24 hours. Cellular uptake of ~75% was observed at the best conditions. This investigation demonstrates that Q-galactan is a potential carrier for gene therapy. Further studies are required in order to investigate the intracellular barriers for establishing an efficient gene delivery system.  

 

 

 

[330] CALCIUM-SIRNA NANOCOMPLEXES: MECHANISM OF CELLULAR UPTAKE AND ENDOSOMAL RELEASE

 

Matan Goldshtein1

 

 

1 Ben Gurion University of the Negev; N/A

 

 

 

Small interfering RNA (siRNA) represents a promising type of therapeutics exploiting the mechanism of RNA interference for silencing target genes. Yet, the clinical translation of siRNA has been limited due to delivery challenges. We recently described a novel Ca2+– siRNA nanocomplex capable of strong but reversible complexation, siRNA protection, cellular uptake, and cytoplasmatic unloading of its cargo. Here, we investigated the importance of Ca2+compared to other bi- or tri-valent cations in creating these nanocomplexes, and the cytocompatibility of the various nanocomplexes. Further, we elucidated cellular entry and endosome release mechanisms of Ca2+-siRNA nanocomplexes. The nanocomplexes were prepared by incubating siRNA (50 nM final) with either Ca2+, Mg2+, Zn2+, Ba2+, Mn2+,  Fe2+ or Fe3+ ions (5 mM for divalent and 3.33mM for Fe3+) Of these nanocomplexes, only those prepared with  Ca2+, Mg2+, Ba2+ andFe3+ were cytocompatible as judged by PrestoBlue® for cell viability. Effective eGFP silencing (~80%) in GFP expressing mouse colon carcinoma CT26 cells was achieved only with Ca2+– siRNA nanocomplexes. Cell uptake studies (using confocal microscopy) and silencing experiments (using flow-cytometry), were performed using different inhibitors of several possible entry mechanisms: Dynasore, Pitstop2®, EIPA, Nifedipine, Cadmium and Genistein. We revealed that the major endocytic pathways involved in the entry of Ca2+-siRNA nanocomplexes are clathrin and dynamin-dependent. Treatment with Bafilomycin, which inhibits endosome acidification after Ca2+ entry to endosomes, completely abolished siRNA-mediated silencing indicating that Ca2+ is critical for the endosomal unloading through a “proton sponge” effect. In conclusion, Ca2+ is a critical component for particle assembly, particle uptake and endosomal escape.

 

 

 

[338] SPECIFICITY IN CANCER THERAPY BASED ON CELL MECHANICS

 

Yifat Brill-Karniely1, Nethanel Friedmann2, Ben-Zion Amoyav3, Ofra Benny4

 

 

1 Institute of Drug Research; The Hebrew University

 

 

2 Institute of Drug Research; Institute of Drug Research

 

 

3 Hebrew University; Idr- Institute Drug Reserch

 

 

4 The Hebrew University of Jerusalem; Institute for Drug Research

 

 

 

Specificity in Cancer Therapy Based on Cell Mechanics

Yifat Brill-Karniely, Nethanel Friedman, Benzion Amoyav and Ofra Benny

School of Pharmacy, Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel

The presented work is composed of a tight cross-talk between computational modelling and advanced experimental methods, aiming to optimize the design of drug carriers for cancer treatment. Our prime aim is to investigate the mechanical mechanism of micro-particle engulfment and uptake by cells. We hypothesize that physical properties of cells control the engulfment process in a manner that can enhance the specificity of cancer therapy. Our work includes a cooperative combination of in vitro experiments, advanced particle fabrication methods and physical modelling. In agreement with our model predictions, we found a binary behavior in particle uptake: cells internalize either many particles or none. Furthermore, according to our theoretical modelling, the rigidity of cells determines their engulfment abilities. Therefore, our findings can potentially lead to significant enhancement of treatment specificity that is based on differences in the physical rigidities between normal and malignant cells, rather than on the expression of specific molecules.

 

 

 

[340] SELF-ASSEMBLED COMPLEXES OF PLASMID DNA AND MODIFIED STARCH FOR ACTIVE DELIVERY INTO THE NUCLEUS

 

Shachar Gat1, Ramesh Chintakunta1, Dina Aronovich1, Tamar  Traitel2, Riki Goldbart2, Anne Bernheim-Groswasser3, Joseph Kost2

 

 

1 Department of Chemical Engineering ; Ben Gurion University

 

 

2 Ben Gurion University of the Negev; Department of Chemical Engineering

 

 

3 Department of Chemical Engineering ; Ilse Kats Institute for Nanoscale Science and Technology

 

 

 

Gene therapy is a novel clinical strategy whereby exogenous genetic material is introduced into human cells for the treatment of hereditary or acquired disorders. The main objective of gene therapy is the development of efficient, non-toxic gene carriers that can condense and deliver foreign genetic materials into specific cell types, such as cancerous cells. Non-viral carriers have advantages over viral carriers, since they have low toxicity and induce low immune response; however, their major disadvantage is their relatively low gene expression. This low productivity relates largely to the poor efficiency of transport the nanoparticle from the plasma membrane to the nucleus and their subsequent import into the nucleus. All trafficking across the nuclear membrane occurs through the nuclear membrane embedded nuclear pore complex (NPC). The import of molecules larger than 45 kDa into the nucleus is mediated by nuclear localization signals (NLS) which recruit import proteins (importins) to their surface as well as motor proteins, thereby mediating their active movement from the plasma membrane toward the nucleus and subsequent docking and import through the NPC.

The objective of this work is to design a carrier that can overcome this limitations; starch, a natural polysaccharide was modified into cationic starch (Q-starch) and was used as a pDNA carrier. Covalent coupling of polyethylene glycol (PEG)-thiol to the Q-starch was carried out in order to attach NLS peptides. Complexation of Q-starch-PEG-thiol with pDNA in different N/P ratios (molar ratio of Q-starch nitrogen groups to nucleic acid phosphate groups) was evaluated by gel electrophoresis. Results showed spherical nanoparticles that are more condensed and their average surface charge increases with the increase of N/P. NLS peptides attachment to the complexes was done by coupling the free end of the polymer (PEG-thiol) to a NLS peptide. Specific binding of the complexes to motor proteins was confirmed by western blot using anti-dynein antibodies and by cryogenic transmission electron microscopy.

 

 

 

[343] FEASIBILITY OF LEADLESS CARDIAC PACING USING INJECTABLE MAGNETIC MICROPARTICLES

 

Hemi Rotenberg1, Hovav Gabay2, Smadar  Cohen3, Yoram Etzion4

 

 

1 Bgu ; Beer Sheva

 

 

2 Regenerative Medicine & Stem Cell Research Center; Ben-Gurion University of the Negev

 

 

3 Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev; Regenerative Medicine and Stem Cell (Rmsc) Research Center and 2the Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel

 

 

4 Regenerative Medicine & Stem Cell Research Center, ; Ben-Gurion University of the Negev, Beer-Sheva, Israel.

 

 

 

An approach for immediate, painless and non-invasive heart pacing may have invaluable implications in several clinical scenarios. We hypothesized that mechano-­electric feedback (MEF) can be utilized to evoke cardiac pacing using injectable magnetic micro or nano-particles. Such particles can be trapped in the right ventricle (RV) by an external electromagnetic force. Thereafter, magnetic pulses banging the particles over the RV wall can initiate leadless electrical pacing. We used ex­-vivo isolated rat heart model to demonstrate the ability to provoke MEF-induced pacing by iron microparticles (IMPs) inserted directly to the RV cavity. In vivo rat model was used to demonstrate the ability to localize IMPs and magnetite nanoparticles (MNPs) in the RV and provoking MEF induced pacing using external electromagnet. Thereafter, this modality was tested in a pig model, by inserting IMPs or MNPs directly to the RV cavity of a blood perfused isolated pig heart.

Isolated rat heart studies showed that MEF-induced overdrive pacing was consistently applied in 5 consecutive hearts by IMPs, subjected to magnetic pulses. The in-­vivo studies demonstrated that the electromagnet effectively captured IMPs and MNPs in the RV. Cryosections of the frozen heart show large aggregates of IMPs and MNPs when the electromagnet was used, while sham hearts were vacant (n=2 for each group). After we showed successful localization, we demonstrated that MEF induced overdrive pacing could temporarily revert bradycardia by applying magnetic pulses on localized IMPs. After appropriate optimizations, overdrive pacing of at least 5s was obtained in 13 out of 15 tested rats. Finally, we demonstrated the efficacy of this modality in a relevant large mammalian pig model; we induced overdrive pacing of an isolated pig heart by applying magnetic pulses on both IMPs and MNPs.

Our results demonstrate an effective modality for selective cardiac pacing in a completely non­invasive fashion. Additional optimization is needed to prolong pacing using this novel approach and to further evaluate its applicability in the intact large mammalian model.

 

 

 

 

 

[493] BI-FUNCTIONAL MAGNETO-FLUORESCENT NANOPARTICLES FOR MULTIMODAL IMAGING

 

Sandip Pahari1, Shunit  Olszakier2, Itamar Kahn3, Lilac Amirav4

 

 

1 Israel Institute of Technology, Technion; Schulich Faculty of Chemistry

 

 

2 The Ruth and Bruce Rappaport Faculty of Medicine ; Technion – Israel Institute of Technology

 

 

3 The Ruth and Bruce Rappaport Faculty of Medicine; Technion – Israel Institute of Technology

 

 

4 Schulich Faculty of Chemistry; Technion – Israel Institute of Technology

 

 

 

Bi-functional Magneto-Fluorescent Nanoparticles for Multimodal Imaging

Sandip Kumar Pahari1, Shunit Olszakier2, Itamar Kahn2, and Lilac Amirav1

1Schulich Faculty of Chemistry,

2Department of Physiology and Biophysics, The Ruth and Bruce Rappaport Faculty of Medicine,

Russell Berrie Nanotechnology Institute, Technion – Israel Institute of Technology, Haifa, Israel.

Tel: +972-4-829-3715. E-mail: lilac@technion.ac.il

Abstract:

Designing effective nanoparticles that can passively or actively label fine biological structures in various functional states is a central goal of medicine-oriented nanotechnology development. Since each established imaging modality has its own drawbacks, integration of different techniques into multimodal imaging can provide complimentary information. Hybrid nanostructures can exhibit several features synergistically and deliver more than one function simultaneously.

In particularly, multifunctional magnetic nanoparticles can have unique advantages in biomedical applications. Here we present our strategy to fabricate magnetic nanoparticle-based multifunctional nanostructures, which are integrated with quantum dots. These hybrid nanostructures exhibit paramagnetism alongside fluorescence. Direct contact between the semiconductor and magnetic domains, typical of traditional core-shell or heterodimer structures, can lead to strong electronic coupling, diminishing the desired optical fluorescence. Hence, our structure comprises an optically active nanoparticle quantum dot core encapsulated in a hollow shell providing the MRI contrast agent. Such encapsulation of the quantum dot might also prove to be essential for biocompatibility and toxicity aspects. We expect that the combination of unique structural characteristics and integrated functions of multicomponent magnetic nanoparticles will lead to new opportunities in biological and medical imaging.

 

 

 

 

 

 

[494] SIRNA DELIVERY PLATFORM BASED ON CO-ASSEMBLING ANIONIC NANOPARTICLES OF SIRNA AND HYALURONAN SULFATE VIA CALCIUM BRIDGES

 

Efrat Forti1

 

 

1 Ben-Gurion University of the Negev; Ben-Gurion University of the Negev

 

 

 

siRNA delivery platform based on co-assembling anionic nanoparticles of siRNA and hyaluronan sulfate via calcium bridges

 

Efrat Forti1, Olga Kryukov1, Edan Elovic1, Matan Goldstein1, Efrat Korin1, Gal Margolis1, Felder Shani 1, Emil Ruvinov1, Smadar Cohen1-3

1Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, 2Regenerative Medicine and Stem Cell (RMSC) Research Center, 3The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel

Therapeutic implementation of gene silencing using small interfering RNA (siRNA) relies on the critical need for a safe and effective carrier for siRNA protection, capable of strong but reversible complexation, cellular uptake, and cytoplasmatic unloading of its cargo. We developed anionic siRNA nanoparticles (NPs) co-assembled by the electrostatic interactions of the semi-synthetic polysaccharide hyaluronan-sulfate (HAS), with siRNA, mediated by calcium ion bridges. Physical characterization of the HAS-Ca2+-siRNA NPs, using high resolution microscopy and dynamic light scattering (DLS), showed the formation of stable nanosized complexes ~130 nm in diameter, bearing mild (~−10 mV) negative surface charge. X-ray photoelectron spectroscopy (XPS) demonstrated the spatial organization of siRNA molecules in the particle core, surrounded by a layer of HAS. The anionic NPs efficiently encapsulated siRNA, were extremely stable in physiological-relevant environments and were cytocompatible, not affecting cell viability or homeostasis. The anionic siRNA NPs, successfully induced potent gene silencing (>80%) across multiple cell types, including murine primary peritoneal macrophages, human hepatocellular carcinoma cells, and human breast cancer cells. The potential toxic effects of anionic NP formulation were tested in mice, following single intravenous injection (IV) of HAS-Ca2+-siRNA. Results showed that acute administration of the HAS-Ca2+-siRNA NPs at a dose of 3.3 mg/kg siRNA via the intravenous (IV) route was not associated with toxic risk. Collectively, the developed anionic NPs were shown to be an efficient and cytocompatible platform for enhancing the therapeutic efficiency of siRNA.

 

 

 

 

 

 

[497] BIO-INSPIRED ANIONIC NANOPARTICLES FOR THE DELIVERY OF PLASMID DNA

 

Stav Shamir1, Efrat Forti2, Matan Goldstein1, Smadar  Cohen3

 

 

1 Ben Gurion University of the Negev; Ben Gurion University of the Negev

 

 

2 Ben-Gurion University of the Negev; Ben-Gurion University of the Negev

 

 

3 Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev; Regenerative Medicine and Stem Cell (Rmsc) Research Center and 2the Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel

 

 

 

Bio-inspired anionic nanoparticles for the delivery of plasmid DNA

Stav Shamir1, Efrat Forti1, Matan Goldstein1, Smadar Cohen1-3

1Avram and Stella Goldstein-Goren Department of Biotechnology Engineering,

2Regenerative Medicine and Stem Cell (RMSC) Research Center,

3The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel

Gene therapy is a promising strategy for the treatment of many diseases including cancer and various genetic disorders by target-specific delivery of therapeutic genes. We are developing a novel anionic nanoparticle (NP) for targeted delivery of plasmid DNA (pDNA). The NPs are assembled by the electrostatic interactions of a modified natural polysaccharide, alginate sulfate (AlgS), with pDNA, mediated by interactions with calcium ion. Characterization of the NPs by dynamic light scattering (DLS) and zeta potential measurements showed an average size of 103±2.8 nm (SEM, n=5) and a mild negative surface charge of -5.8±0.3 (SEM, n=9). Encapsulation efficiently was estimated by ethidium bromide exclusion assay and found to be 62.2% ± 0.8% (SEM, n=9). The pDNA NPs did not affect cell viability, and efficient cellular uptake of fluorescently-labeled anionic pDNA NPs was observed (95%) in the human breast cancer cell line MDA-MB 231 by imaging flow cytometry. Collectively, anionic pDNA NPs show a promise to be an efficient and cytocompatible delivery system for pDNA.

 

 

 

 

 

[506] PHARMACOLOGIC STUDIES OF A PRO-DRUG OF MITONYCIN C IN PEGYLATED LIPOSOMES (PROMITIL)

 

Patricia Ohana1, Hilary Shmeeda2, Yogita Patil3, Yasmine Amitay4, Alberto Gabizon3

 

 

1 Lipomedix Pharmaceuticals Ltd. ; Shaare Zedek Medical Center

 

 

2 Shaare Zedek Medical Center; Shaare Zede Medical Center

 

 

3 Shaare Zedek Medical Center; Shaare Zedek Medical Center

 

 

4 Lipomedix Pharmaceuticals Ltd.; Shaare Zedek Medical Center

 

 

 

Pharmacologic studies of a prodrug of mitomycin C in pegylated liposomes (Promitil®)

Purpose: Pegylated liposomal (PL) mitomycin C lipid-based prodrug (MLP) has recently entered clinical testing. We studied the preclinical and clinical pharmacology of PL-MLP.

Methods: The stability, pharmacokinetics, biodistribution, and other pharmacologic parameters of PL-MLP were examined. Thiolytic cleavage of MLP and release of active mitomycin C (MMC) were studied using dithiothreitol (DTT), and by incubation with tissue homogenates. Pharmacokinetic data were collected from a dose escalation phase 1 study in cancer patients.

Results: MLP was incorporated in the bilayer at 10% molar ratio with nearly 100% entrapment efficiency, resulting in a formulation with high plasma stability. In vitro, DTT induced cleavage of MLP with predictable kinetics, generating MMC and enhancing pharmacological activity. A long half-life of MLP (10-15 hours) was observed in rodents and minipigs. PL-MLP was less toxic in vivo than equivalent doses of MMC. Studies in mice with H3-cholesterol radiolabeled PL-MLP demonstrated relatively greater tissue levels of H3 than MLP. MLP levels were highest in tumor and spleen, and very low or undetectable in liver and lung. Rapid cleavage of MLP in various tissues, particularly in liver, was shown in ex-vivo experiments of PL-MLP with tissue homogenates. Urine from PL-MLP injected rats revealed delayed but significant excretion of MMC indicating in vivo activation of MLP. Therapeutic studies in C26 mouse tumor models demonstrated improved dose-dependent efficacy of PL-MLP over MMC.

The pharmacokinetics of PL-MLP in a first-in-man study showed a median t1/2 of 23 hours, with no trend by dose or cycle, while Cmax and AUC0-∞ increased linearly over the dose range 0.5-2.0 mg/kg, and greater than linearly from 2.5-3.5 mg/kg. No free MMC was detected. The results were consistent with preclinical observations.

Conclusions: Thiolytic activation of PL-MLP occurs in tissues but not in plasma. Liposomal delivery of MLP confers a favorable pharmacological profile and greater therapeutic index than MMC. Further clinical testing is ongoing.

 

 

 

[508] NANOPARTICULATE DELIVERY OF SIRNA/MIRNA TO MODULATE CARDIAC MACROPHAGES TOWARDS HEART REPAIR

 

tzlil bejerano1, Sharon etzion2, Sigal Elyagon 2, Yoram etzion2, Smadar Cohen3

 

 

1 Avram and Stella Goldstein-Goren Department of Biotechnology Engineering; Ben Gurion University

 

 

2 Regenerative Medicine and Stem Cell (Rmsc) Research Center; Ben-Gurion University of the Negev

 

 

3 Avram and Stella Goldstein-Goren Department of Biotechnology Engineering; Regenerative Medicine and Stem Cell (Rmsc) Research Center

 

 

 

The wound healing process after myocardial infarction (MI) is tightly controlled by different macrophage sub-populations: inflammatory macrophages (M1 type) and reparatory macrophages (M2 type). An excessive activity of M1 macrophages resulting from a delay in the transition from M1 to M2 macrophage often leads to heart failure. We hypothesized that modulation of cardiac macrophages from M1 to M2 phenotype, at the proper time-point after MI, using miRNA delivery, may attenuate infarct expansion and adverse left-ventricular remodeling. For this purpose, we developed siRNA/miRNA carrying nanoparticles (NPs) formed by the co-assembly of siRNA/miRNA with the semi-synthetic glycosaminoglycan, hyaluronan-sulfate, mediated by calcium ion bridges. The NPs were characterized, and exhibited efficient siRNA entrapment, protection from enzymatic degradation, enhanced cellular uptake, and effective gene silencing across multiple cell types. The NPs have an average diameter of 125 nm, and a mild negative surface charge (-11.3mV). In vivo uptake studies of NPs containing fluorescently labeled Cy3-siRNA were conducted initially in mice stimulated with peritoneal sterile infection. One hour after intraperitoneal (IP) injection, FACS analysis showed NP uptake in 40% of the peritoneal macrophages. In a model of acute MI in mice, intravenous  (IV) injection of NPs 3 days after MI, resulted in accumulation of Cy3-siRNA in CD11b (monocyte/macrophage marker)-positive cells at the infarct area. An in vivo imaging system (IVIS) analysis showed ~30% higher signal of cy5-siRNA NPs in infarcted hearts, relative to healthy hearts. These results indicate the feasibility of our NPs to target macrophages at the infarct and efficiently deliver siRNA/miRNA to enable their immunomodulation.  The multidisciplinary approach presented in this research combines engineering of miRNA delivery system and cardiac macrophage biology. Ultimately we foresee this approach to lead to a novel bio-inspired therapeutic modality for heart repair after acute MI.

 

 

 

[537] LIPOSOME-BASED NANO-DRUGS FOR THE TREATMENT OF CANCER AND INFLAMMATION

 

Keren Turjeman1, Ahuva Cern2, Xiaohui Wei3, Yaelle Bavli4, Tal Berman5, Alexander  V. Andriyanov6, Moria Barlev-Gross7, Lisa Silverman8, Alexander Lyskin8, Yechezkel (Chezy)  Barenholz9

 

 

1 Laboratory of Liposome and Membrane Research, Imric, The Hebrew University-Hadassah Medical School, Jerusalem, Israel; Hebrew University

 

 

2 Biochemistry Department; Hebrew University

 

 

3 Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada (Imric); The Hebrew University-Hadassah Medical School,

 

 

4 Laboratory for Membrane and Liposome Research, Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada (Imric), The Hebrew University of Jerusalem, Hadassah Medical School; Hebrew University

 

 

5 Department of Biochemistry and Molecular Biology, Institute of Medical Research Israel-Canada (Imric) The Hebrew University of Jerusalem, Hadassah Medical School ; The Hebrew University – Hadassah Medical School

 

 

6 Laboratory of Liposome and Membrane Research; Imric

 

 

7 Laboratory of Liposome and Membrane Research; The Hebrew University of Jerusalem

 

 

8 Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada (Imric); The Hebrew University – Hadassah Medical School

 

 

9 Institute of Medical Research Israel-Canada (Imric), ; The Hebrew University of Jerusalem

 

 

 

Liposome-based nano-drugs for the treatment of cancer and inflammation

 

Keren Turjeman, Ahuva Cern, Xiaohui Wei, Yaelle Bavli, Tal Berman, Alexander Andriyanov, Moria Barlev-Gross, Liza Silverman, Alexander Lyskin, Prof. Yechezkel Barenholz

 

Laboratory of Membrane and Liposome Research, Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University-Hadassah Medical School

 

Abstract

The Barenholz lab focuses on the development and application of liposome-based nano-drugs, ranging from basic aspects of drug-carrier design, through preclinical and clinical trials, all the way to FDA-approved drugs.

We have developed injectable nano-drug delivery systems based on pegylated, long-circulating, nano sterically stabilized liposomes (nSSL) remotely loaded with either amphipathic weak acid, anti-inflammatory steroid pro-drugs, or with doxorubicin; an amphipathic weak base, anti-cancer agent. We applied the bio-energetic strategy of transmembrane ion-gradient-driven remote loading, by which, liposomes encapsulate a salt containing either a weak base (e.g. ammonium) or a weak acid (e.g. acetate). This remote drug loading method has three main advantages over passive drug loading: high drug loading efficiency, a high drug-to-lipid mole ratio, and controlled drug release both in vitro and in vivo.  These nano-drugs are specifically designed to use the unique micro-anatomical vascular abnormality of inflamed and cancerous tissues: this phenomenon is called the “enhanced permeability and retention” (EPR) effect. The pegylation of the nano-liposomes by the lipopolymer PEG-DSPE provides steric stabilization, which results in prolonged circulation time, size-dependent passive targeting, and drug accumulation in the diseased tissue.

All lead to reduced toxicity and improved efficacy.

 

 

 

[539] ELECTRICALLY-CONTROLLED REDOX STATE MOIETY POPULATION ON NANOWIRE SURFACE AS A TOOL FOR MULTIPLEX, REAL-TIME AND CONTINUOUS MONITORING OF METABOLITES

 

Marina Zverzhinetsky1, Vadim Krivitsky2, Vladimir Naddaka3, Fernando Patolsky3

 

 

1 Tel-Aviv University; School of Chemistry, the Raymond and Beverly Sackler Faculty of Exact Sciences

 

 

2 Tel Aviv University; School of Chemistry, the Raymond and Beverly Sackler Faculty of Exact Sciences

 

 

3 School of Chemistry; School of Chemistry

 

 

 

Electrically-Controlled Redox State Moiety Population on Nanowire Surface as a Tool for Multiplex, Real-Time and Continuous Monitoring of Metabolites

Marina Zverzhinetsky†, Vadim Krivitsky†, Vladimir Naddaka† and Fernando Patolsky

 

†School of Chemistry, the Raymond and Beverly Sackler Faculty of Exact Sciences,

 Tel-Aviv University, Israel

 

Abstract

The development of efficient sensors for the continuous monitoring of metabolic activity is of a critical importance in modern medicine and bio-sample analysis, primarily due to the fact that most bio-samples are mixtures of high diversity and complexity. We designed a redox-reactive nanowire biosensor for multiplex, real-time and continuous monitoring of metabolic activity in physiological environment. The surface of the nanowire sensor was covalently modified with redox-reversible moiety, while the reversible transformation can happen either by applying chemicals or voltage. In order to make continuous measurements of metabolic activity, the reversible redox properties of the modified moiety were used. Importantly, this represents the direct analysis of bio-samples on a single nanowire device, which is able to selectively detect specific metabolites, without the requirement of time-consuming steps, such as labeling and purification. Remarkably, first nanowire continuous sensing of metabolites in physiological solutions without preprocessing was realized. Typically, concentration-dependent sensing of metabolites covers physiological concentration ranges.

 

Extension of the Generic Amyloid Hypothesis to Non-Proteinaceous Metabolite Nano-Assemblies

 

Shira Shaham-Niv1, Lihi Adler-Abramovich1,2, Lee Schnaider1 and Ehud Gazit1,3

1Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel. 2Department of Oral Biology, The Goldschleger School of Dental Medicine, Tel Aviv Univeristy, Tel Aviv 69978, Israel.

3Department of Materials Science and Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel.

 

Keywords: Amyloid fibril formation, metabolic disorders, supramolecular nano-assemblies, drug development, self-assembly.

 

The formation of ordered amyloid fibrils is associated with several notable human disorders. These nano-scale assemblies are predominantly rich in β-sheet secondary structure and specifically bind dyes, such as ThT and Congo-red. The formation of the amyloid fibrils or earlier pre-fibrillar forms correlates to an apoptotic effect in various tissues. While the formation of these cytotoxic supramolecular entities has previously been linked to proteins and peptides, it was later demonstrated that phenylalanine, as a single amino-acid, can also self-assemble to form amyloid-like fibrils possessing typical ultrastructural, biophysical and biochemical properties. Moreover, it was demonstrated that these phenylalanine assemblies are cytotoxic and antibodies raised against these species deplete fibril toxicity. The generation of antibodies in a phenylketonuria (PKU) mice model and identification of aggregate deposits post mortem in patients’ brains suggested a pathological role for these assemblies. To study whether these observations represent a general amyloid-like mechanism prevalent in other metabolic disorders, we have screened metabolites that accumulate in inborn error of metabolism disorders. Here, we reveal that several other metabolites can self-assemble to form ordered amyloid-like ultrastructure in solution with the molecular dimensions and dye-binding specificity similar to canonical amyloid fibrils. In addition, we show that these fibrillar self-assemblies are cytotoxic by the induction of apoptotic programmed cell death, as observed for many amyloid disorders. These results suggest that the formation of nano-scale amyloid-like self-assemblies by metabolites indicate to a general phenomenon of amyloid formation beyond proteins and peptides and offer a new paradigm for metabolic diseases. This may lead to new therapeutic directions of treatments for these disorders beyond a highly-restrictive diet.

Nano-Mechanics

 

 

[169] ELECTRICAL AND ELECTROMECHANICAL PROPERTIES OF WS2 NANOTUBES

 

Roi Levi1, Jonathan Garel1, David Teich2, Gotthard Seifert2, Reshef Tenne1, Ernesto Joselevich1

1 Department of Materials and Interfaces; Weizmann Institute of Science
2 Technische Universität Dresden; Theoretische Chemie

Electrical and electromechanical properties of WS2 nanotubes
Roi Levi, Materials and Interfaces Department, Weizmann Institute of Science, Israel
roi.levi@weizmann.ac.il
Jonathan Garel, Materials and Interfaces Department, Weizmann Institute of Science, Israel
David Teich, Theoretische Chemie, Technische Universität Dresden, Germany
Gotthard Seifert, Theoretische Chemie, Technische Universität Dresden, Germany
Reshef Tenne, Materials and Interfaces Department, Weizmann Institute of Science, Israel
Ernesto Joselevich, Materials and Interfaces Department, Weizmann Institute of Science, Israel

The use of nanostructures such as nanotubes and 2D sheets in electrical and electromechanical devices is the subject of intensive research in recent years. In particular, the electronic properties of inorganic compounds such as the dichlcogenides sparked the research of their incorporation into nano-electro-mechanical systems (NEMS). WS2 nanotubes (INT-WS2) have been shown to exhibit superior mechanical properties and interesting stick-slip mechanical phenomena1 and thus are a natural candidate for electro-mechanical devices.
We show here that INT-WS2 possess significant field-effect mobility and surprisingly high current carrying capacity2. We further present the first demonstration of a significant electro-mechanical response in pure inorganic nanotubes3. The INT-WS2 exhibited a highly repeatable increase of the conductivity in response to strain and/or torsion. These results are in qualitative agreement with the theoretical calculations presented here for torsion and strain. The large sensitivity to torsion and tension suggests INT-WS2 as promising in NEMS such as nano-gyroscopes and accelerometers.

Figure 1. a. Schematics of a WS2 nanotube-based torsional nano-electro-mechanical system (NEMS) and the atomic force microscope (AFM) tip used to perform the torsion. b. INT-WS2-NEMS electrical response to torsion – change in conductivity with the torsion angle. Inset – AFM image of the INT-WS2-NEMS.
References
(1) Nagapriya, K. S.; Goldbart, O.; Kaplan-Ashiri, I.; Seifert, G.; Tenne, R.; Joselevich, E. Physical Review Letters 2008, 101, 195501.
(2) Levi, R.; Bitton, O.; Leitus, G.; Tenne, R.; Joselevich, E. Nano Letters 2013, 13, 3736-3741.
(3) Levi, R.; Garel, J.;Teich, D.; Seifert, G.; Tenne, R.; Joselevich, E. ACS Nano 2015, Article ASAP.

 

[394] MULTI-LEGGED DNA-BASED MOLECULAR MOTORS

 

Yaron Berger1, Toma Tomov2, Roman Tsukanov3, Miran Liber2, Eyal Nir2

1 Ben-Gurion University; Ilse Katz Institute for Nanoscale Science & Technology
2 Ben-Gurion University of the Negev; Ilse Katz Institute for Nanoscale Science & Technology
3 Ben Gurion University; Ilse Katz Institute for Nanoscale Science & Technology

Multi-Legged DNA-Based Molecular Motors

Yaron Berger, Toma E. Tomov, Roman Tsukanov, Miran Liber and Eyal Nir
Department of Chemistry, Ben-Gurion University of the Negev, Be’er-Sheva, Israel

Abstract
Natural molecular machines, made of proteins, play a major role in many important biological processes, often with impressive operational yields and speeds. Inspired by biological bipedal motors such as kinesin and with the assistance of single-molecule fluorescence and computer controlled microfluidic device we designed and operated a DNA-based bipedal motor that can stride on a DNA origami track with high operational yield. The reaction yield was 98% per step, which results in overall operational yield of 50% for 36 steps. To the best of our knowledge, this is the highest operational yield achieved by artificial molecular motors so far; however, it is not sufficient for repeatable operation of molecular machines for technological usage, for example, such as molecular assembly line and efficient maneuvering and manipulation of guest molecules.
This work focuses on the effort to understand the reasons for the 5-10% walker dissociation, and to increase walker processivity, operational yield and speed. To achieve a basic understanding of the motor’s limiting factors, kinetic measurements were made for the different reactions that make up a step, resulting with empiric reaction rates. We later built a kinetic numeric simulation to describe the correlation between each reaction rate and the final stepping yield. One possible solution for the walker dissociation is the multi-leg and multi-foothold approach, in which the walker consists of two pairs of legs and the track consist two rows of footholds. Preliminary results show an increase in yield per reaction of about two times, when operated 10uM fuel concentration. The walker, which consists of four legs, was prepared using “click” chemistry, and the motor, operated by microfluidics, was evaluated using single-molecule fluorescence

 

[538] NANO-SUBMARINES

 

Jonathan Jeffet1, Victor Garcia-Lopez2, James M. Tour3, Yuval Ebenstein4

1 Raymond and Beverly Sackler Faculty of Exact Sciences; Tel Aviv University
2 Angel Marti Research Group; Dept. of Chemistry, Rice University
3 Rice University; Smalley Institute for Nanoscale Science & Technology
4 School of Chemistry; Tel Aviv University

Nano-submarines
Jonathan Jeffet1, Víctor García-López 2, James M. Tour2 & Yuval Ebenstein1
1Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv
2Department of Chemistry, Rice University, Texas

Molecular motors in the single nano meter scale have not yet been observed to generate propulsion. We utilize single molecule imaging of fluorescent submersible nano machines, in order to assess whether or not sufficient amount of work could be exerted by the motor to propel the nano machine and overcome the dominant viscosity forces in this extremely low Reynolds number regime.
In order to accomplish this goal, the nano machines are imaged inside silicon nano channels with a 45 nm cross section, that serve as “nano-tracks” confining the diffusion of the machines in one dimension. The nano machines contain conjugated fluorescent molecules that allow tracking their position when excited with a 637nm laser. The nano machines’ motors are activated by a UV laser generating rotation of a molecular rotor. The trajectories of the machines inside the nano channels are then analyzed and via the measurement of mean squared displacement we aim to assess the diffusion differences between activated and non-activated molecules. Thus, we wish to estimate the work done by the motor and confirm its effectiveness.

 

AN INNOVATIVE APPROACH TO MULTI GAS DETECTION AND PRESSURE MEASUREMENTS:NANO TECHNOLOGIES AND MECHANICS FOR A NOVEL GENERATION OF MINIATURE, MECHATRONIC ANALYTICAL INSTRUMENTS AND WIDE RANGE, ON CHIP PRESSURE DEVICE

 

Raffaele Correale, Gianpiero Mensa, Valter Maccantelli

NanoTech Analysis s.r.l.s

Corso Re Umberto, 65

10121 Torino, Italy

 

NanoTech Analysis strategic intent is to realize a new generation of proprietary, universal and ultra-simplified instruments to perform pressure and chemical measurements offering at the same time enormous state of art analytical systems simplification.

In fact, the combination of recent developments in the field of micro- and nanotechnologies (MEMS and NEMS) with technologies for chemical analysis and fluid dynamic measurements[1] changes fundamentally the manner in which these measurements could be performed.

With that respect, creating specific synergies and leveraging on these smart combinations, NTA gives origin to an innovative new generation of instruments employing MEMS and NEMS developments to bring the measurements to the level of miniaturization.

NTA future portfolio of products and proprietary technology have been protected via a series of eight patents[2]. Our instruments derive from two technological and completely innovative platforms. The first one relies on a universal, miniaturized (even on-chip) single pressure sensor device covering more than 18 orders of magnitude in pressure[3] and able to identify any gas in its operating range.

The second platform gives origin to a new generation of miniature, mechatronic analytical instruments able to measure any volatile compounds in any environment processing at molecular level the minimum possible number of molecules.

Therefore, main purposes are to present NTA feasibility studies as well as original and innovative instruments layouts. In addition, same experimental set up and measurements will be presented as well. Moreover, extremely relevant appears to be the impact of our technology and products (above all in the domain of miniature and portable multi gas analyzer) when applied in domains as Defense and homeland security, Aerospace, automotive fields, environmental applications and some bio medical applications.

In fact, the baseline idea is to challenge in the smartest way the MEMS and NEMS Semiconductors Industry to realize complex Electro Mechanical Analogical devices and instrumentation (Mechatronic).

Therefore, smart miniaturization becomes for NTA an enabling factor to definitively allow unmet devices’ performances, simplify potential OEM systems, optimize operations, allow unpredictable integration potential into several different domain and applications.

 

[1] E.g. pressure measurements and standard gas analyzers.

[2] WIPO – PCT filings.

[3] E.g. from 10-13 mbar to >104 mbar.

Nano-Materials

[21] GUIDED GROWTH OF CDS NANOWALLS WITH CONTROLLED ORIENTATIONS FOR HIGH-PERFORMANCE NANO-MISFET AND PHOTODETECTOR ARRAYS

 

Jinyou Xu1, Ernesto Joselevich1

1 Department of Materials and Interfaces; Weizmann Institute of Science

Guided Growth of CdS Nanowalls with Controlled Orientations for High-Performance nano-MISFET and Photodetector Arrays.
Jinyou Xu†, Ronit Popovitz-Biro‡, Katya Rechav‡, Lothar Houben‡, Ernesto Joselevich*†.
†Department of Materials and Interfaces, ‡Chemical Research Support, Weizmann Institute of Science, Rehovot 76100, Israel

Controlled alignment of semiconductor nanostructures plays key roles for large-scale integration of them into functional nanodevices. Here we report the horizontally guided growth of CdS nanowalls with controlled crystallo-graphic orientations on both flat and faceted sapphires by a simple thermal evaporation route. HRTEM, GPA and micro-PL analyses confirmed the high single-crystal quality of these nanowalls. On the basis of these horizontally self-aligned nanowalls arrays, nano-MISFETs and photodetectors arrays were conveniently fabricated in a wafer scale (cm2) and high-performances were achieved. Most of the nano-MISFETs work in a E-mode (normally off) with on/off current ratio of 108 and a highest transconductance of 1.1 µS. The on/off ratio is four orders of magnitude higher than the best reported results for E-mode CdS nano-FETs. The best rise and decay time of the photodetectors is ~1 µs and the 3-dB bandwidth is ~350 kHz, which is one order of magnitude faster than the best results reported so far. Therefore, the present route holds promising to develop large-scale fabrication of high-performance semiconductor nanodevices.

 

[25] ULTRA HIGH-YIELD SYNTHESIS OF SELF-ASSEMBLED, CONDUCTIVE, AND SUPERHYDROPHOBIC THREE-DIMENSIONAL MATS OF CARBON NANOFIBERS VIA FULL CATALYSIS OF UNCONSTRAINED THIN FILM

 

Efrat Shawat Avraham1, Ilana Perelshtein1, Andrew westover2, Cary L. pint2, Daniel Nessim3

1 Bar-Ilan University; Bar-Ilan University
2 Vanderbilt University, Nashville, Tn ; Vanderbilt University, Nashville, Tn
3 Bar-Ilan Institute of Nanotechnology and Advanced Materials; Bar-Ilan University

Ultra high-yield synthesis of self-assembled, conductive, and superhydrophobic three-dimensional mats of carbon nanofibers via full catalysis of unconstrained thin film
Efrat Shawat1, Ilana Perelshtein1, Andrew Westover2, Cary L. Pint2, and Gilbert D. Nessim1*

Abstract:
Carbon nanofibers (CNFs) are ideal candidates for a range of important applications; However, to realize industrial application of these materials, processes must be developed to produce CNfs with desired structural characteristics, and with high yields.
Using a specific weak adhesion layer between the CNf catalyst and the substrate, we produced a catalytic thin film that delaminates inside our CVD reactor during synthesis. Following delamination, removal of the mechanical constraint of the catalyst layer to the substrate led to mats of carbon nanofibers that were 3X to 5X larger than the substrate they originated from. The mass of these three-dimensional (3-D) CNF mats made of cm-long Following an extensive characterization of the morphology and structure of the CNF mats in concert with a parametric study of the effect of temperature, pre-anneal conditions, growth duration, and substrate materials, we found evidence of a correlation between growth conditions and the 3-D mat morphological properties. This work gives insight into a new growth process whereby high yields of 3-D carbon nanostructures can be directly obtained with from an unconstrained catalytic thin film, utilizing a rational choice of catalyst/underlayer combinations and growth conditions. This yield is over an order of magnitude higher compared to the “standard” substrate-constrained catalytic growth. Based on the extensive characterizations done to date, we can explain specific aspects of the new growth mechanisms based on thin film evolution, simultaneous delamination, and carbon nucleation of the catalytic thin film. Such materials have significant promise as conductive material scaffolds for a wide-range of next-generation materials that can take advantage of the high surface area and good mechanical robustness of such CNF structures.

 

[26] CATALYST RESERVOIR FOR SYNTHESIS OF TALLER CARPETS OF CRYSTALLINE AND VERTICALLY ALIGNED CARBON NANOTUBES

 

Efrat Shawat Avraham1

1 Bar-Ilan University; Bar-Ilan University

Catalyst reservoir for synthesis of taller carpets of crystalline and vertically aligned carbon nanotubes
Efrat Shawat, Dr. Yafit Fleger, Dr. Cary L. Pint , Dr. Gilbert Daniel Nessim
The Department of Chemistry and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan , 52900, Israel

Abstract:
Overcoming growth termination remains a challenge for the synthesis of long CNTs. As it has been proposed that the termination of growth is correlated with catalyst morphology evolution and subsurface diffusion of catalyst, we propose here the design of a catalyst stack composed of a thin oxide support under which resides a catalyst reservoir to replenish the catalyst during CNT synthesis, and hence enhance the lifetime and activity of the catalyst. Specifically, we compared samples with e-beam evaporated Fe thin film catalyst on Al2O3 underlayer and samples with an additional thin Fe reservoir beneath the alumina underlayer. With the inclusion of the Fe sublayer, we synthesized CNT carpets that were up to 100% taller compared to those samples without the Fe sublayer. The effectiveness of the Fe sublayer was observed for wide variations of process parameters such as growth duration and temperature. High-resolution imaging confirms the presence of carpets composed of crystalline and vertically aligned CNTs with lengths up to almost 2mm.AFM carried out on samples using comparable process conditions showed a bimodal formation of Fe catalysts for the samples with the Fe sublayer, and subsequent etching experiments emphasize the presence of pinholes in the alumina support which enables the redistribution of Fe catalyst from the sublayer to the overlayer. A study of samples with varying thicknesses of the alumina underlayer further confirmed this hypothesis as thicker alumina layers exhibited shorter CNT growth due to the presence of fewer pinholes. This result is significant as it elucidates further mechanistic aspects of CNT growth and provides a new technique to extend the active lifetime of CNT growth catalyst, and thus enhance the CNT length.

 

[31] 3X TALLER CARPETS OF VERTICALLY ALIGNED CARBON NANOTUBES THROUGH DIFFERENTIAL PREHEATING OF HYDROCARBON DECOMPOSITION AND WATER FORMATION

 

Eti Teblum1, Reut Yemini1, Mijael Chababo1, Efrat Shawat Avraham1, Merav Muallem2, Daniel Nessim2

1 Bar-Ilan University; Bar-Ilan University
2 Bar-Ilan Institute of Nanotechnology and Advanced Materials; Bar-Ilan University

It has been shown that preheating the incoming hydrocarbon precursors and of forming water vapor from oxygen and hydrogen can significantly affect the growth of vertically aligned carpets of carbon nanotubes (CNTs). In this study, we performed differential preheating of the incoming gases to decouple the water formation and the hydrocarbon decomposition processes. We identified different process parameter sweet spots for water vapor formation (formed by reacting H2 and O2) and for hydrocarbon decomposition as well as significantly increasing the height of our CNT carpets. Specifically, we revealed that the optimal preheating temperature for hydrocarbon formation is quite lower compared to the optimal preheating temperature required water decomposition.
We used a sophisticated system of multi-zone thermal chemical vapor deposition (CVD) furnaces in parallel and in series to study the effects of thermal preheating of these precursors prior to their reaching the growth zone. We analyzed a dozen of possible preheating combinations and showed how an appropriate combination of gas residence times for both hydrocarbons and water formation can significantly increase CNT growth to exceed 3 mm in height. Extensive AFM, HRTEM and SEM characterizations of the CNTs indicate how preheating affects the CNT height, diameter, and crystallinity. This analysis helps to better understand the mechanisms at play for the precursor gases prior to reaching the sample and helps to design more efficient synthesis systems for CNT growth. Moreover, this insight may open the door to the development of more sophisticated thermal CVD system where different incoming precursors are heating differently to optimize the growth of CNTs and possibly of other nanostuctures.

 

[39] ENGINEERING OF IRON-BASED MAGNETIC NANOPARTICLES FOR ENVIRONMENTAL REMEDIATION APPLICATIONS

 

Hai Haham1, shlomo Margel2

1 Department of Chemistry; The Institute of Nanotechnology and Advanced Materials
2 Biu; Department of Chemistry & The Institute of Nanotechnology and Advanced Materials

Engineering of Iron-Based Magnetic Nanoparticles for Environmental Remediation Applications
Hai Haham and Shlomo Margel

Magnetic nanoparticles represent a new generation of environmental remediation technologies that could provide cost-effective solutions to some of the most challenging environmental contamination problems. This study presents two methods for engineering iron-containing water treatment utilities based on: (a) magnetic nanoparticles; (b) magnetic carbon fabrics. Magnetic Fe nanoparticles coated with carbon layers were obtained by thermal decomposition of ferrocene mixed with polyvinylprrolydone (PVP) at 350 ˚C, followed by thermal annealing at 600 ˚C in inert atmosphere. Magnetic activated carbon fabrics (ACF) were produced by thermal decomposition of iron acetylacetanoate impregnated within the ACF at different temperatures in inert atmosphere. The influence of the annealing temperature on the chemical composition, shape, crystallinity, surface area, pore volume and magnetic properties was elucidated for both cases. The Fe nanoparticles obtained in these two methods were doped with tinier Pd nanoparticles for catalysis applications. The engineered utilities were tested on two classes of pollutants (haloganted and azo dyes) and illustrated the enhanced decomposition of the dyes from an aqueous solution according to the following order: Fe/Pd > Fe > Fe3O4.

 

[43] SUBSTRATE STRAIN, IT’S DETERIORATING EFFECT ON THE TRANSPORT PROPERTIES OF THE VO2 METAL-INSULATOR TRANSITION AND HOW TO OVERCOME IT

 

Tony Yamin1, Amos Sharoni2

1 Biu; Bar-Ilan Institute of Nanotechnology & Advanced Materials
2 Biu; Department of Physics & The Institute of Nanotechnology and Advanced Materials

Substrate strain, it’s deteriorating effect on the transport properties of the VO2 metal-insulator transition and how to overcome it

When growing functional oxide thin films the substrate matching and induced strain play crucial roles on the resulting film’s electronic and structural properties. In VO2 this often results in a minimum deposition thickness necessary for the appearance of the metal insulator transition (MIT), where increasing thickness further changes the properties of the transition until full relaxation.
We developed a delicate wet etching process for thinning epitaxial films of VO2 grown on R-cut sapphire, which can open a new path for fabrication of ultra-thin devices based on VO2.
Our initial 60 nm thick film showed a sharp MIT of ~ 4 orders of magnitude. The film was etched, in a number of steps, to below 10 nm. We find that the transport properties of the etched film did not change substantially till the film was thinned below 15 nm, and also film below 10 nm showed MIT. This is in contradiction to films that were deposited to 20nm or below and had no phase transition. We report the transport, XRD and TEM properties of the thinned films and the films deposited at different thickness, and discuss the correlation between structure and transport properties, and the different routes to control the substrate strain.

 

[51] CITRAL ENCAPSULATION TO CHITOSAN-BASED EDIBLE FILMS AND COATINGS UTILIZING NANO-EMULSION APPROACH

 

Hadar Arnon1, Elena Poverenov2, Ron Porat2

1 Agriculture Research Organization (Aro); Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem
2 Agricultural Research Organzation (Aro); Postharvest and Food Sciences, Food Quality and Safety

Citral encapsulation to chitosan-based edible films and coatings utilizing
nano-emulsion approach
Active edible coatings may provide a natural safe and biodegradable alternative to synthetic preserving agent for prolonging shelf life of fruits and vegetables. In this study citral, a natural aroma and antimicrobial agent, was encapsulated to a chitosan-based coating formulation utilizing nano-emulsion approach. The properties and functionality of the nano-emulsions containing formulation were compared to those of the conventional coarse emulsions containing formulations. DLS analysis showed that nano-emulsion had higher monodispersity than the coarse emulsion. The surface structure, seen from E-SEM studies was found to be more organized in edible films based on nano-emulsions. Encapsulation of citral generally impaired the mechanical properties of the films; however the negative effect of nano-emulsions is significantly smaller than that of the coarse emulsions. Moreover, nano-emulsions even increased the ‘elongation at break’ value. The water vapor permeability (WVP) of chitosan edible films was not significantly impaired by citral encapsulation. The effect of the active edible coatings was examined on fresh-cut melons model. The nano-emulsions based coatings demonstrated advanced performance. The antimicrobial effect of the coatings was studied utilizing different concentrations of citral (0.8, 1.6, 2.4 % v/v). It was found that 1.6% (v/v) and especially 2.4% (v/v) citral significantly inhibited the microbial growth during all examination period (13 days).

 

[53] FABRICITION OF N-HALAMINE NANOPARTICLES FOR ANTIMICROBIAL AND ANTIFOULING APPLICATIONS

 

Michal Natan1, Ori Gutman1, Shlomo Margel1, Ehud Banin2

1 The Institute for Advanced Materials and Nanotechnology; Bar Ilan University
2 The Mina and Everard Goodman Faculty of Life Sciences; The Institute for Advanced Materials and Nanotechnology

Increased resistance of bacteria to antimicrobials and their ability to form biofilms, many of them are essentially untreatable, pose a serious public health threat worldwide. This has prompted the search for agents that can inhibit both bacterial growth and withstand harsh conditions (e.g., high organic loads). In the current study, N-halamine-derivatized cross-linked polymethacrylamide nanoparticles (NPs) were synthesized by co-polymerization of the monomer methacrylamide (MAA) and the cross-linker monomer N,N-methylenebisacrylamide (MBAA), and were subsequently loaded with oxidative chlorine, using sodium hypochlorite (NaOCl). The chlorinated NPs demonstrated remarkable stability and durability to organic reagents and to repetitive bacterial loading cycles as compared with the common disinfectant NaOCl (bleach), which was extremely labile under these conditions. The antibacterial mechanism of the cross-linked P(MAA-MBAA)-Cl NPs was found to involve generation of reactive oxygen species (ROS) only upon exposure to organic media. Importantly, ROS were not generated upon suspension in water, revealing that the mode of action is target-specific. Further, a unique and specific interaction of the chlorinated NPs with Staphylococcus aureus was discovered, whereby these microorganisms were all specifically targeted and marked for destruction. This bacterial encircling was achieved without using a targeting module (e.g., an antibody or a ligand) and represents a highly beneficial, natural property of the P(MAA-MBAA)-Cl nano-structures. Finally, P(MAA-MBAA)-Cl NPs embedded within irrigation drippers were shown to prevent fouling on them compared with the control, hence providing the drippers with ‘self-cleaning’ and ‘self-sterilizing’ properties. In summary, our findings underscore the potential of developing sustainable P(MAA-MBAA)-Cl NPs-based devices for inhibiting bacterial colonization and growth.

 

[60] SIZE DEPENDENT LIGAND LAYER DYNAMICS IN SEMICONDUCTOR NANOCRYSTALS PROBED BY ANISOTROPY MEASUREMENTS

 

Ido Hadar1, Tasfrir Abir1, Shira Halivni2, Adam Faust3, Uri Banin4

1 Institute of Chemistry and the Center for Nanoscience and Nanotechnology; The Hebrew University of Jerusalem
2 Hebrew University of Jerusale; Physical Chemistry
3 Institute of Chemistry and the Center for Nanoscience and Nanotechnology ; The Hebrew University of Jerusalem
4 Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University, Jerusalem ; The Hebrew University of Jerusalem

Colloidal semiconductor nanocrystals (NCs) are promising building blocks for various applications. This is mainly due to the ability to modify the physical and chemical properties of the semiconductor material via bottom-up approaches by controlling the particles size and shape in the nanometer scale. The inorganic NC surface is usually covered by an organic ligands layer, making NCs a unique inorganic-organic hybrid chemical system. The ligand shell has a crucial role in the colloidal synthesis as it allows controlling the size and shape of the NCs. Modifying the properties of the ligand shell allows controlling the NCs dispersibility in various solvents and matrices to control their physical and chemical properties and to adapt them for specific applications. Although the major importance of the ligand shell its exact properties and specifically the effect of the NC size and shape on these properties are still not well understood. This is mainly due to the lack of experimental tools that will enable to study the organic ligands shell in situ. In our current research we have uniquely studied the physical properties of the ligand shell on the surface of spherical quantum-dots (QDs), of various sizes. We have utilized organic dye molecules that are embedded within the ligands layer and adopt its properties to optically study the effective viscosity of the ligand shell. By tracing the reorientation times of the dye molecules we were able to calculate the effective viscosity of the ligand layer. We have found that as the size of the QD decreases (and hence the curvature increases), the effective viscosity of the ligands shell is decreasing. The ability to control the physical properties of the ligand shell simply by changing the shape of the surface is a unique property of NCs. Further investigation of the ligand shell will allow rational design of the surface to achieve desired properties, providing an additional important knob for tuning their functionality.

 

[61] SYNTHESIS AND CHARACTERIZATION OF SPIROPYRAN PHOTOCHROMIC FLUORESCENT POLYMERIC NANOPARTICLES BY EMULSION POLYMERIZATION

 

Sharon Bretler1, Uriel Bretler2, shlomo Margel3

1 Department of Chemistry; The Institute of Nanotechnology and Advanced Materials
2 Bar Ilan Institute of Nanotechnology and Advanced Materials; The Institute of Nanotechnology and Advanced Materials
3 Biu; Department of Chemistry & The Institute of Nanotechnology and Advanced Materials

Abstract:
Photochromic fluorescent nanoparticles were prepared by emulsion polymerization of styrene (S), butylmethacrylate (BMA), and monomer spiropyran dye (MSP) to obtain Poly(S/BMA/MSP) uniform nanoparticles.
The influence of various polymerization parameters (e.g., concentration of the monomers, initiator, and the surfactant) on the properties of the particles size, and size distribution has been elucidated.
Spiropyran is colorless and non-fluorescent at the spiro conformation. Moreover, spiropyran at the merocyanine conformation is non-fluorescent in water or in non-polar organic solvents. Once the merocyanine conformation spiropyran is entrapped within polymer particles, the particles exhibit blue color and strong red fluorescence.
Absorbance and fluorescence measurements reveal that higher BMA concentration at the polymerization reaction leads to a higher absorbance and fluorescence intensity of the Poly(S/BMA/MSP) nanoparticles.
The photoisomerization of the Poly(S/BMA/MSP) nanoparticles studied by exposing the nanoparticles dispersion to alternate UV and visible light cycles, the fluorescence intensity measurements reveal a reversible photochromism.

 

[65] CONTROLLING FORMATION OF NANOSTRUCTURES AND MICROSTRUCTURES WITH ACOUSTIC WAVES

 

Haim Sazan1, Michael Layani2, Silvia Piperno3, Shlomo Magdassi4, Hagay Shpaisman5

1 Bar-Ilan University; Nano Technology Institute
2 Casali Institute for Applied Chemistry; Institute of Chemistry
3 Chemistry Department.; Bar Ilan University
4 Casali Center of Applied Chemistry; The Hebrew University of Jerusalem
5 Bar Ilan University; Nanotechnology Institute

Abstract – Controlling Formation of Nanostructures and Microstructures with Acoustic Waves

Haim Sazan1, Michael Layani2, Silvia Piperno1, Shlomo Magdassi2, Hagay Shpaisman1
1The Nanotechnology Institute, Chemistry Department, Bar-Ilan University, Ramat-Gan, Israel
2Casali Institute for Applied Chemistry, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel

In this research, I study how standing surface acoustic waves (SSAWs) affect the formation of structures from suspended nanoparticle solutions and control chemical reactions. Recently, SSAWs were used to selectively promote coalescence and to create ordered colloidal crystals and metamaterials. SSAWs could be used to create new microstructures – metallic, polymeric and hybrid (organic-inorganic) materials and to control surface reactions. Under the exposure of SSAWs, nanoparticles in a microfluidic channel would be forced towards pressure nodes (for particles with a positive acoustic contrast factor in the medium). If the acoustic force pushing them together is stronger than the electrostatic forces arising from their charges, coalescence and partial fusion could occur. When the system partly fuses, we predict that microstructures will be formed following the contour of the nodes.
I investigate the formation of microstructures by silver nanoparticles sintering. These nanoparticles can be sintered at room temperature with exposure to chloride ions. Streaming the silver suspended nanoparticles with chloride ions solution under the SSAWs field could sinter the particles in a micro-fiber shape.
Another project is controlling chemical reaction, such as crystallization growth of titanium oxide, by SSAWs exposure. As opposed to the silver nanoparticles sintering where the nanoparticles are being arranged instantly by the acoustic waves and then the stabilizer is removed to form nano/microstructures, here crystals grow along the pressure nodes lines.

Illustration (not to scale) of pattern formation due to the effect of SSAW on particles inside a microfluidic channel

 

[83] VISCOELASTIC PROPERTIES OF FROZEN INTERFACIAL NANO-LAYERS: DIRECT OPTICAL MICROSCOPY

 

Moshe Caspi1, Alexander V. Butenko1, Eli Sloutskin1

1 Physics Department and Bar-Ilan Institute for Nanotechnology and Advanced Materials, Bar-Ilan University; Institute for Nanotechnology and Advanced Materials

Viscoelastic properties of frozen interfacial nano-layers:
Direct optical microscopy
M. Caspi, A. V. Butenko, and E. Sloutskin
Physics Department and Institute of Nanotechnology and Advanced Materials,
Bar-Ilan University, Ramat-Gan 5290002, Israel
The classical theory of elasticity is a continuum approximation. In nano-scale systems, where the relevant length scale approaches the dimensions of atoms and molecules, this continuum approximation is doomed to fail. However, even the most fundamental concepts of nanoelasticity, beyond the limits of the continuum approximation, are yet not established.
We employ passive microrheology to study the viscoelastic properties of a quasi-two-dimensional crystalline nano-layer, which spontaneously self-assembles at the interface between oil and water. The properties of oil-water interfaces play a dominant role in a wide range of systems in science and technology. It has been recently discovered[L. Tamam et al. PNAS (2011)], that tiny concentrations of certain surfactants make the interface between oil and water undergo a freezing transition at T=Ts. At a high temperature (T>Ts), the ~2nm thick monomolecular interfacial layer, composed of a mixture of oil (linear alkane) molecules and surfactants, is molten. At a lower temperature (T<Ts), the monolayer crystallizes, about 10-20oC above the freezing temperature of the bulk oil. The elastic properties of this crystalline interfacial monolayer play a dramatic role for oil in water droplets: the droplets, down to sub-femtolitre sizes, become faceted and, under certain conditions, mix spontaneously with water, overcoming the hydrophobic repulsion[S. Guttman et al. PNAS (under revision, 2015)]. Yet the viscoelasticity of the interfacially-frozen monolayers has never been measured before.
We follow, by direct confocal microscopy, the Brownian motion of simple colloidal spheres, embedded in a monolayer between bulk hexadecane (C16-alkane) and an aqueous sub-mM solution of linear ionic surfactants (C18TAB). The viscoelastic properties of the interfacial monolayer are probed for a range of different temperatures, both below and above Ts, potentially allowing the future paradigm of nanoscale elasticity to be established based on direct experiments.

 

[90] SONOCHEMICAL SYNTHESIS OF ZNO-PVA NANOFLUID AS POTENTIAL BIOCIDAL AGENT

 

Anjani Nagvenkar1

1 Bar- Ilan University, ; Institute for Nanotechnology and Advanced Materials

Sonochemical synthesis of ZnO-PVA nanofluid as a potential biocidal agent
Anjani Nagvenkar, † Archana Deokar, † Ilana Perelshtein, † Aharon Gedanken†§
†Department of Chemistry, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
§Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan
Abstract
The study aimed at synthesizing ZnO in colloidal form with greater stability and higher antibacterial activity. From practical application point of view, for the incorporation of ZnO into liquid products the use of a stabilizer becomes necessary but synthesizing nanoparticles with high dispersity in solution still remains a challenge. So herein we attempt the synthesis of ZnO in colloidal form by employing a biocompatible polymer, PVA (poly(vinyl alcohol)) as a stabilizing agent to achieve stability on the one hand and minimum particle size of ZnO on the other hand. Both ZnO (without PVA) and ZnO-PVA are synthesized using ultrasonic irradiation and the difference in their particle size, stability and antibacterial activity was correlated. Furthermore, ESR measurements reveal that ZnO with reduced particle size produced increased levels of reactive-oxygen species (ROS). The biocidal effect of the colloidal solution was performed on two bacterial species: Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) revealed an enhancement in the antibacterial activity for the ZnO-PVA nanofluid.

 

[98] CONTROLLING WIRE FORMATIONS WITH LASER INDUCED MICROBUBBLES

 

Nina Armon1, Hagay Shpaisman2, Michael Layani3, Shlomo Magdassi4, Udi Greenberg2

1 Bar Ilan University; Nanotechnology Institure
2 Bar Ilan University; Nanotechnology Institute
3 Casali Institute for Applied Chemistry; Institute of Chemistry
4 Casali Center of Applied Chemistry; The Hebrew University of Jerusalem

Controlling wire formations with laser induced microbubbles
Nina Armon1, Michael Layani2, Udi Greenberg1, Shlomo Magdassi2, Hagay Shpaisman1
1The Nanotechnology Institute, Chemistry Department, Bar-Ilan University, Ramat-Gan, Israel
2Casali Institute for Applied Chemistry, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
In my research I focus on directing nano-particles to form microstructures by induced laser light. My sample is composed of an aqueous solution of the micro/nano particles that are dispersed between two glass slides. As the focused laser beam heats the micro/nano particles solution vapor pressure rises and can result in the formation of a microbubble. This causes a temperature gradient in the vicinity of the bubble that gives rise to strong Gibbs−Marangoni convection currents. As a result of the flow, the micro/nano particles are pushed towards the edge of the bubble/glass contact area and can be pinned there. Moving the focused beam relative to the sample results in the migration of the microbubble, thus continuously depositing fresh material at the bubble/glass contact area.
Since previous work has shown fragmented lines, our goal was to learn how to get better control over the microbubble in order to produce continuous lines with minimum width. As a model system we used solutions of Ag nano particles with a polyacrylic acid coating in different solvents. We have found that modulating (altering the frequency and duty cycle) the exposure time of the laser beam can significantly improve the quality of the forming lines. Additionally, we found a strong dependence on the boiling point of the solvent, intensity of the laser, microscope’s stage velocity, microscope’s magnification and material concentration in the solution.

 

[99] EFFECT OF OVERLAYERS ON THE GROWTH OF CARBON NANOTUBE FOREST

 

Reut Yemini1, Daniel Nessim2

1 Bar-Ilan University; Bar-Ilan University
2 Bar-Ilan Institute of Nanotechnology and Advanced Materials; Bar-Ilan University

Effect of overlayers on the growth of carbon nanotube forest
Reur Yemini and Gilbert D. Nessim

Since the discovery of carbon nanotubes and the fundamental understanding of their growth mechanism, most researchers focused on the influence of different growth parameters and variety of substrates on vertically aligned carbon nanotubes (VACNTs) growth. Most research has focused on understanding the role of catalysts, underlayers, gases, and most recently thin film reservoirs position below the alumina underlayer. In this study, we demonstrate the effect of different metallic bridges positioned above the catalytic layer on the growth of VACNTs using thermal chemical vapor deposition (CVD). We show that the growth of CNTs can be enhanced or inhibited by using different materials. Using patterned metal foils or wires we were able to pattern regions with CNTs of varying height with regions without CNTs. For instance, we show how copper inhibited CNT growth while titanium bridges led to taller CNTs beneath. Using HRTEM and HRSEM we will show the effect of these metallic bridges on the catalyst morphology and on the CNT structure. We will discuss mechanisms of how the bridges affect the precursor gases in proximity of the catalytic layer. This research shows how we can control CNT growth on different regions of the same sample, without the need to pattern the catalyst.

 

 

 

 

[110] PLATINUM FREE CATALYSTS FOR HYDROGEN OXIDATION REACTION (HOR) IN ALKALINE FUEL CELLS

 

Masha Alesker1

1 Bar Ilan University; Bina Institute

Platinum Free catalysts for Hydrogen Oxidation Reaction (HOR) in Alkaline Fuel Cells
Maria Alesker, Meital Shviro, David Zitoun

Department of Chemistry, Nanomaterials Research Center, Bar Ilan Institute of Technology and Advanced Materials (BINA), Bar Ilan University, Ramat-Gan, 52900, Israel

Investigation of the hydrogen oxidation reaction (HOR) in alkaline media has been pursued in the past few years side by side with the development of alkaline membrane fuel cells (AMFCs), also called anion exchange membrane fuel cells (AEM-FCs). We present the synthesis, electrochemistry and AMFC test of a platinum-free HOR catalyst. The anode catalyst is prepared by the synthesis of a tri-component nano-composite of carbon, palladium and an oxophilic metal (nickel), resulting in nano-dispersed, interconnected crystalline phases of Ni and Pd. When used in the anode of a hydrogen/air AMFC, such Pd/Ni catalyst exhibits high HOR activity, resulting in record high performance for a platinum-free AMFC. The enhancement of HOR catalytic activity vs. that observed at Pd (or Ni) alone is revealed directly in rotating disc electrode tests of this Pd/Ni catalyst that shows a significant negative shift (200 mV) of the onset potential for the HOR current vs. the case of Pd.

 

[114] IN SITU FORMATION OF CARBON DOTS AIDS AMPICILLIN SENSING

 

Rahul Mishra1, Indra Neel Pulidindi1, Eihab Kabha1, Aharon Gedanken2

1 Bar Ilan University; Department of Chemistry
2 Bar-Ilan University; Department of Chemistry

In situ formation of carbon dots aids ampicillin sensing
Rahul Kumar Mishraa, Indra Neel Pulidindia, Eihab Kabhaa, Aharon Gedankena, b*
aDepartment of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel
bNational Cheng Kung University, Department of Materials Science and Engineering, Tainan 70101, Taiwan
Tel: +972-3-5318315; Fax: +972-3-7384053;
*E-mail: gedanken@mail.biu.ac.il
Abstract:
A simple analytical method is designed for the detection of micro molar concentrations of antibiotics with β- lactam subunit. The sensor for the ampicillin has a limit of detection, LOD value of 0.165 x 10-4 M and exhibited linearity over a wide range of ampicillin concentration 6.6 – 200 ppm. The detection of antibiotic is based on the in situ generation of carbon nano dots (CND’s) via a hydrothermal reaction between glucose and the antibiotic moiety. The CND’s exhibited characteristic absorption at 340 nm whose intensity is a measure of the initial ampicillin concentration. The CND’s possess peculiar blue emission which is excitation dependent. The particle size of CND’s is in the range of 8-40 nm (Fig. 1) and are hydrophilic. NMR spectral analysis revealed insights into the carbon nano structure comprising of aromatic core with carbonyl type functionalities on the surface.

Fig. 1 . TEM image of carbon dots aided the sensing of ampicillin

 

[120] A NOVEL METHOD OF FUNCTIONALIZATION OF INORGANIC TUNGSTEN DISULFIDE NANOTUBES

 

Daniel Raichman1

1 Bar-Ilan University; Chemistry Department

A novel method of functionalization of inorganic tungsten disulfide nanotubes
Daniel Raichman, Rina B. Binyamini and Jean Paul Lellouche
Bar-Ilan Institute of Nanotechnology & Advanced Materials
The covalent attachment of functional ligands such as photo or redox active molecular species onto the surface of inorganic WS2 nanotubes is an important first step towards the design of new mechanically hard materials/matrices. Such successful applications, however, will strongly fuel surface chemical modifications for best contacting phase compatibility.A new method of functionalization/polycarboxylation on the surface of WS2 inorganic nanotubes was successfully developed using electrophilic species (Scheme below). This main functionalization trend was to enable a wide range of INT surface modifications via polyCOOH group chemical activation such as outer polyamine, polyalcohol and polythiol shells, in order to best covalently bind to epoxy resins as an illustrative filled polymeric matrix.

 

[131] SIZE AND SHAPE-CONTROLLED SYNTHESIS OF AIR STABLE PBSE COLLOIDAL QUANTUM DOTS

 

Youngjin Jang1, Aldona Sashchiuk1, Efrat Lifshitz1

1 Technion; Schulich Faculty of Chemistry, Russell Berrie Nanotechnology Institute, Solid State Institute

Size and Shape-Controlled Synthesis of Air Stable PbSe Colloidal Quantum Dots
Youngjin Jang, Aldona Sashchiuk, and Efrat Lifshitz*
Schulich Faculty of Chemistry, Russell Berrie Nanotechnology Institute, Solid State Institute,
Technion, Haifa 32000, Israel

IV-VI Colloidal quantum dots (CQDs) have attracted a great attention to scientific interest and technological applications because of their unique size-dependent optical and electronic properties. Recently, the interest of CQDs exhibiting the optical properties which are active in near-infrared (NIR) (0.75-1.4 μm) and short wavelength infrared (SWIR) regime (1.4 -3 μm) is gradually growing because NIR and SWIR region are highly important for optoelectronic and imaging applications such as a photodetector and a night vision. However, the study of IV-VI CQDs that exhibit in NIR and SWIR range has been rarely done, therefore, it is still challenging. In addition, the synthesis of air stable IV-VI CQDs is highly crucial for diverse applications because IV-VI CQDs are prone to oxidation under ambient atmosphere. I present a colloidal synthesis of PbSe CQDs having the absorption in NIR and SWIR region. The size control of PbSe CQDs is achieved by adjusting the reaction temperature and the stability of PbSe CQDs against air is improved by halide treatment.

 

[136] NANOMETRIC OXIDE COATING ON POLYETHYLENE

 

Yacov Carmiel1, Chaim Sukenik2

1 Bar Ilan University; Department of Chemistry
2 Bar-Ilan University; Department of Chemistry

Nanometric oxide coating on Polyethylene
Polyethylene is widely used in the industry due to its low cost and good mechanical properties. However, its low surface energy makes it unsuitable for coating and painting. Nanometric layers (5-100 nm) of various metal-oxides have been deposited on high density polyethylene (HDPE), improving its long term hydrophilicity. The oxides were deposited by 2 methods: Liquid phase deposition (LPD) for TiO2 and SnO2, and atomic layer deposition (ALD) for TiO2, Al2O3, and ZnO. The oxide layer is very robust, as has been shown by mechanical testing of the coating. The oxide layer improves the wetting of the surface and enables adhesion of paints and other adhesives. The growth rate of the oxides was assessed by ellipsometry for the ALD deposited oxides, and by FIB-SEM cross section for the LPD deposited oxides.

 

[142] UNDERSTANDING THE MECHANISM OF INTERACTIONS BETWEEN A 12MER PEPTIDE AND HYDROXYAPATITE CRYSTALS USING SINGLE MOLECULE FORCE SPECTROSCOPY

 

tal duanis-assaf1, Meital Reches2

1 Institute of Chemistry, Hebrew University; Center for Nanoscience and Nanotechnology, Hebrew University
2 The Hebrew University of Jerusalem; The Center for Nanoscience and Nanotechnology

Understanding the mechanism of interactions between a 12mer peptide and hydroxyapatite crystals using single molecule force spectroscopy
Duanis-Assaf T., Reches M.
Institute of Chemistry and The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem.
Human hard tissues such as bones and dentine are composed of an organic-inorganic composite material containing an organic phase of mainly collagen-I fibrils and hydroxyapatite (HAp) crystals. Such biological composites are formed in processes of self-assembly referred to as biomineralization. The processes of biomineralization are not yet completely understood, however, they are thought to be governed by the surface interactions between the organic and inorganic phases. The mechanism of adhesion of organic molecules to inorganic surfaces is not clear. Before major breakthroughs are achieved in engineering new organic-inorganic hybrid materials, further investigation of this mechanism is required.
The purpose of this study is to investigate the interactions between a peptide and HAp as a model for the organic-inorganic hybrid material in human bone tissue.
The interaction between HAp tablets and a 12mer peptide which is known to adhere to HAp was investigated using single molecule force spectroscopy (SMFS) using atomic force microscope (AFM).

 

[146] SHAPE-DEPENDENCE OF CONTACT STABILITY OF METAL NANOPARTICLE-CARBON COMPOSITE FOR ENERGY AND BIOMEDICAL APPLICATIONS

 

Mary Clare Escano1

1 Graduate School of Engineering; University of Fukui

Shape-dependence of contact stability of metal nanoparticle-carbon composite for energy and biomedical applications

Mary Clare Sison Escaño
Graduate School of Engineering, University of Fukui, 3-9-9 Bunkyo, Fukui, 910-8507 Japan

Metal nanoparticle (NP) synthesis methods have been improving recently especially in terms of achieving control over structural properties including shape. Moreover, the metal NP – carbon composite is widely used in future power devices such as fuel cell and in biomedical applications such as drug delivery. However, the contact stability of the NP-carbon composite based on shape has not been understood.
In the conference, the most stable NP will be presented based on computational simulation of 1-2nm Pt nanoparticles on carbon. The computational simulation method is based on density functional theory (DFT) conducted on larger scale to accommodate both atomistic and electronic properties of more realistic NP-carbon sizes. Using these comprehensively studied properties, the predictor of the contact stability of NP-carbon composite material is derived. Such stability predictor allows inventors, experimentalists and computational simulation researchers alike to obtain quick stability information of NP-carbon systems without the need for intensive structural property tests.

Reference:
MCS Escaño. NanoResearch 2015 8, 1689-1697.

 

[153] CONTROLLING THE SHORT-RANGE ORDER OF AMORPHOUS OXIDES BY NANOMETER SIZE

 

Yael Etinger-Geller1, Alexander Katsman2, Boaz Pokroy1

1 Technion; Department of Materials Science and Engineering
2 Department of Materials Science and Engineering, Technion − Israel Institute of Technology; Nr

Amorphous materials, in contrast to crystalline ones, lack long-range order. Its order decays rapidly with the distance; yet, the local environment for a particular type of atom is quite similar – though not identical. These fine changes in the atomistic structure of the materials lead to new and very interesting phenomena which are unique for amorphous materials. Although many aspects of science and technology rely on amorphous materials, much less research is conducted about their structure than on their crystalline counterparts.
In nature there are many organisms that use crystallization via an amorphous phase in order to achieve controlled mineralization. One of the main advantages of this method is that it enables the organism to exert control over the resulting polymorph, which is not necessarily the thermodynamic stable one.
We chose atomic layer deposition (ALD) as our material deposition method, since it is a technique that can provide extremely precise, sub-nanometric, thickness control and can deposit conformal and pinhole-free amorphous films of various materials.
It was shown lately in our group that indeed the short-range ordering changes as a function of size in amorphous aluminum-oxide. The results show that the surface of the amorphous alumina possesses a different short-range order than the average in its bulk, so the thinner the amorphous solid is, the more its short-range order resembles that near the surface
In this research we continue the study on how size affects the short-range order of different amorphous systems and correlate these changes to different properties. We believe that this amazing strategy if adopted for man-made materials could revolutionize many technological applications.

 

[155] MAXIMYZING THE POTENTIAL OF LAYERED COMPOUNDS FOR HYDROGEN PRODUCTION

 

Oren Meiron1, Lothar Houben2, Maya Bar Sadan3

1 Ben Gurion University; Ben Gurion University
2 Weizmann Institute of Science; Weizmann Institute of Science
3 Ben Gurion University ; Ben Gurion University

Maximyzing the potential of layered compounds for hydrogen production
Oren E. Meiron1, Houben Lothar2, Maya Bar-Sadan1
1Ben Gurion University of the Negev, the chemistry department, Beer Sheba, Israel
2 Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
Abstract: Layered transition metal dichalcogenides (TMDs) gained much attention in recent years. Layer edges were identified as the catalytic sites, making edge oriented morphologies a desired design. In addition, first principle calculations showed that doping and alloying of TMDs can be used to modify their electronic properties. To date, TMD alloying is primeraly performed at high temperature, solid state reactions, such as chemical vapor deposition (CVD) or chemical vapor transport (CVT) which limit morphology and composition control. We used low temperature, controllable colloidal synthesis to produce nanoflower alloyed TMDs. Specifically Mo(SxSe1-x)2 nanoflowers with edge oriented nanostructures. A range of alloy compositions were prepared. The Materials were analyzed using TEM, XRD, UV-Vis, ICP-MS spectroscopy and electron tomography. We found that the produced nanoflowers were molybdenum rich, in agreement with previous reports. The composition closely follows the feed ratio enabling the production of precisely controlled compositions. XRD and UV-Vis spectra results suggests the formation of a homogeneous solid solution rather than two separate phases of MoS2 and MoSe2. Tunable bandgap was achieved as a function of alloying degree, as measured by UV-Vis. Time series analysis results support a growth mechanism of fast-precipitating amorphous material, followed by crystallization of a few layers of small sheets, which curl and tangle around themselves. We have demonstrated the synthesis of improved edge oriented alloys using simple colloidal technique. By controlling the alloying degrees, the electronic properties of the TMDs can be optimized for a variety of applications such as photo catalysis, optoelectronics, transistors and many others.

 

[168] STRUCTURAL AND CHEMICAL TEMPLATING OF ATOMIC LAYER DEPOSITION OF AL2O3

 

Noga Kornblum1, Oleg Kreinin1, Maria Koifman2, Boaz Pokroy1

1 Technion; Department of Materials Science and Engineering
2 Department of Materials Science and Engineering, Technion − Israel Institute of Technology; Russell Berrie Nanotechnology Institute, Technion − Israel Institute of Technology

Atomic layer deposition (ALD) is a method used to deposit high-quality conformal thin films.
The most prominent feature that makes the ALD technique different among the alternative growth methods is its self-limiting characteristic which enables control over the thickness and the composition of the grown film, as well as high conformality and uniformity of the film.
ALD has gained its fame during the mid. 90’s, when the semiconductors industry decided to utilize its abilities in the pursuit after smaller devices dimensions. Nevertheless, the specified advantages of this method were found highly useful for other fields, such as in optoelectronic devices, catalytic cells, nanotechnology, etc., and can be found in many different industries nowadays.
Current processes for selective thin films patterning such as photolithography, are tremendously expensive, complicated and demand special equipment and training. Therefore, there is a need for more available methods for this purpose.
In this work, we study the effect of structural surface modification using high surface energy sites, as well as chemical modification, on the selectively deposited thin alumina films. We believe that this methodology might open new ways to selectively deposit thin films without the need to perform several fabrication steps such as photolithography and etching.

 

[172] SURFACE AND BULK: ARE THEY ALWAYS THE SAME? X-RAY PHOTOELECTRON SPECTROSCOPY STUDY.

 

Tatyana Bendikov1, Delina Barats-Damatov2, Burkhard Butschke2, Jonathan Bauer2, Juan Pellegrino Morono2, Thomas Zell2, Ronny Neumann2, David Milstein2

1 Weizmann Institute of Science; Department of Chemical Research Support
2 Weizmann Institute of Science; Department of Organic Chemistry

Surface And Bulk: Are They Always The Same?
X-ray Photoelectron Spectroscopy Study.

Tatyana Bendikov1, Delina Barats-Damatov2, Burkhard Butschke2, Jonathan Bauer2,
Juan Pellegrino Morono2, Thomas Zell2, Ronny Neumann2, David Milstein2

Departments of 1Chemical Research Support and 2Organic Chemistry,
Weizmann Institute of Science, Rehovot 76100, Israel
e-mail: tatyana.bendikov@weizmann.ac.il

X-ray Photoelectron Spectroscopy (XPS) is a surface sensitive technique (top 10-15 nm) with sensitivity down to single atomic layer. XPS provides unique information about elemental composition and on the chemical and electronic state of the element in the material. The importance of XPS analysis is essential when the top surface and bulk of the material are different in chemical composition and, consequently, in their properties.
We present here two systems where XPS analysis shows significant differences in elemental composition of the top surface, compared to bulk material characterized by various analytical techniques, such as X-ray crystallography, NMR, EPR, Raman and infrared spectroscopies, etc.
In the first system, influence of temperature on the crystal packing and secondary structure of phosphovanadomolybdic acid, H5PV2Mo10O40 was studied.1 After high temperatures treatment (400-600C) XPS analysis reveals enrichment of the top surface of the H5PV2Mo10O40 by amorphous vanadate/phosphate layer.
In the second system, series of iron-PNN complexes were synthesized and characterized in terms of their stability, elemental composition and metal center oxidation state.2-3 Using example of two complexes, [(tBuPNN)Fe(NO)2]+[BF4]- and [(tBuPNN)Fe(NO)¬2]2+2[BF4]-, PNN= 2-[(Di-tert-butylphosphinomethyl)-6-diethylaminomethyl)pyridine, it is shown by XPS study that NO ligands are not stable and easily escape from the complex. This reveals changes in structure and in paramagnetic/diamagnetic behavior of these complexes.

1. Barats-Damatov D., Shimon L.J., Feldman I., Bendikov T., Neumann R. Inorg. Chem. 2015, 54, 628-634.
2. Zell T., Milko P., Fillman K.L., Diskin-Posner Y., Bendikov T., Iron M.A., Leitus G., Ben-David Y., Neidig M.L., Milstein D. Chem. Eur. J. 2014, 20, 4403-4413.
3. Butschke B., Fillman K.L., Bendikov T., Shimon L.J., Diskin-Posner Y, Leitus G., Gorelsky S.I., Neidig M.L., Milstein D. Inorg. Chem. 2015, 54, 4909-4926.

 

[180] GUIDED GROWTH OF HORIZONTAL ZNSE NANOWIRES AND THEIR INTEGRATION INTO HIGH-PERFORMANCE BLUE-UV PHOTODETECTORS

 

Eitan Oksenberg1, Ronit Popovitz Biro2, Katya Rechav2, Ernesto Joselevich3

1 Materials and Interfaces; Weizmann Institute of Science
2 Department of Chemical Research Support; Weizmann Institute of Science
3 Department of Materials and Interfaces; Weizmann Institute of Science

The organization of nanowires on surfaces is one of the main obstacles toward their large-scale integration into functional devices. Recently, our group developed a new bottom-up approach of “guided growth” (Science 2011, 333, 1003), demonstrating horizontal growth of nanowires along specific directions of a substrate, producing perfectly aligned arrays of nanowires. Horizontal growth of semiconductor nanowires has been implemented with several materials and substrates, but to date, none of them have band gap energies in the visible range on a transparent substrate, such as needed for optoelectronic applications. In the present manuscript, we report the guided growth of horizontally aligned ZnSe nanowires with either wurtzite (hexagonal) or zincblende (cubic) structure and different crystallographic orientations, which are exquisitely controlled by the epitaxial relations with different planes of sapphire. This is, to the best of our knowledge, the first report of horizontal nanowires of a visible-range optoelectronic material on a transparent substrate. The guided growth enables the parallel integration of the nanowires of this important optoelectronic material into blue-UV photodetectors, exhibiting the lowest dark current and the fastest measured rise and decay times for devices based on ZnSe 1D nanostructures.

 

[181] ANTIBIOFOULING SURFACE MODIFICATION OF SYNTHETIC POLYMERS WITH FUNCTIONAL SILICA NANOPARTICLES

 

Yonit Boguslavsky1, Yulia Gololobova2, Moshe Shemesh1, Elena Poverenov3

1 Agriculture Research Organization – Volcani Center; Agriculture Research Organization – Volcani Center
2 Agriculture Research Organization (Aro) – Volcani Center; Agriculture Research Organization (Aro) – Volcani Center
3 Agricultural Research Organzation (Aro); Postharvest and Food Sciences, Food Quality and Safety

Antibiofouling surface modification of synthetic polymers with functional silica nanoparticles
Boguslavsky Yonit, Gololobova Yulia, Shemesh Moshe, Poverenov Elena
Department of Food Quality and Safety
Agriculture Research Organization (ARO) – Volcani Center, Bet Dagan, Israel
Polyethylene (PE) , polystyrene (PS) and polyvinyl chloride (PVC) are among the most prevalent polymers that are used in all areas of modern life, ranging from various packaging material to medicinal equipment. However, polymer surfaces are most prone to bacterial colonization that causes adverse effects in various areas, resulting in contamination of medical devices, food contamination and biofouling. Therefore it is necessary to perform antibiofouling surface modification of these polymer films. Indeed chemical inertness of these polymers may significantly limit their versatility in surface modification, so here we present a novel non-invasive and effective method for surface modification of the synthetic polymer films with silica nanoparticles. Silica nanoparticles were created on the surface of the polymer films via tetraethyl orthosilicate (the precursor) adsorption and further silica nanoparticles growth by base catalyzed sol-gel method. The obtained silica NPs will serve as anchors for subsequent covalent attachment of antimicrobial agent, for example, contact active agent as quaternary ammonium salt (QAS). The modified films were characterized by SEM, FTIR and XPS techniques and preliminary biological evaluations were performed.

[183] NANOFILMS FOR ENHANCED PERFORMANCE OF MICROFLUIDIC DEVICES

Mirit Hen1, Chaim Sukenik2, Doron Gerber3

1 Bar-Ilan University; Institute for Nanotechnology and Advanced Materials-Bar Ilan Univrtsity
2 Bar-Ilan University; Department of Chemistry
3 Bar-Ilan University; Institute for Nanotechnology and Advanced Materials-Bar Ilan University

Nanofilms for enhanced performance of microfluidic devices
Mirit Hen1,2, Doron Gerber2,3,Chaim N. Sukenik1,2
1 Department of Chemistry, Bar-Ilan University, Ramat-Gan, 52900, Israel
2 Bar-Ilan Institute of Nanotechnology & Advanced Materials (BINA), Ramat-Gan, 52900, Israel
3 Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel

Microfluidic-based protein arrays are promising tools for life science research and development. They often provide increased sensitivity and specificity. We report the use of both organic and inorganic nanometric films for enhanced performance of microfluidic devices. These efforts focus on two areas: down-scaling the devices and developing new approaches for stable protein attachment within the device channels.
The down-scaling requires finding ways to enable the devices to withstand the higher internal pressure that will result from smaller microfluidic channels. To this end, we fabricate microstructured surfaces that improve water mobility within the channels of the device by decreasing the resistance to solvent flow. This is based on the creation of an inorganic layer that provides a template for enhanced surface hydrophobicity.
To fully optimize this system, these structures are combined with surfaces that have been shown to provide for stable, specific binding of proteins. As a general approach to stable protein attachment, we have developed a general method that involves depositing siloxane-anchored self-assembled monolayers based on 1-undecyl-thioacetate-trichlorosilane (C11TA). We successfully demonstrated the ability to produce, within an integrated microfluidic channel, a C11TA monolayer with a covalently conjugated antibody. The surface functionalization chemistry can be included as part of the fabrication of the device, thus eliminating the time consuming step of surface functionalization at the beginning of each protein array experiment.

 

[190] SELF-ASSEMBLY OF AZIDE CONTAINING DIPEPTIDES

 

Sivan Yuran1, Yair Razvag1, Priyadip Sas1, Meital Reches1

1 The Institute of Chemistry; The Center for Nanoscience and Nanotechnology

Self-assembly of azide containing dipeptides

Sivan Yuran, Yair Razvag, Priyadip Das and Meital Reches
Institute of Chemistry & the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Israel
In nature, complex functional structures are formed by the self-assembly of biomolecules such as amino acids, nucleic acids and phospholipids under mild conditions. Understanding the forces that control self-assembly and mimicking this process in vitro will bring to major advances in the area of materials science.
Peptides, specifically, hold a great promise as biomolecular building blocks since they present substantial diversity, their synthesis in large scale is straightforward, and they can be easily modified with biological and chemical entities.
We present the self-assembly of three aromatic dipeptides containing an azide moiety: H-Phe(4-azido)-Phe(4-azido)-OH, H-Phe(4-azido)-Phe-OH, and H-Phe-Phe(4-azido)-OH. The peptide H-Phe(4-azido)-Phe(4-azido)-OH self-assembled into porous spherical structures, whereas the peptides H-Phe(4-azido)-Phe-OH and H-Phe-Phe(4-azido)-OH did not form any ordered structures under the examined experimental conditions. The azido group of the peptide can serve as a photo cross-linking agent upon irradiation with UV light. To examine the effect of this group and its activity on the self-assembled structures, we irradiated the assemblies in solution for different time periods. Using electron microscopy, we determined that the porous spherical assemblies formed by the peptide H-Phe(4-azido)-Phe(4-azido)-OH underwent a structural change upon irradiation. Moreover, using indentation experiments with atomic force microscopy, we showed that the Young’s modulus of the spherical assemblies increased after irradiation with UV light. These ordered assemblies or their peptide monomer building blocks can potentially be incorporated into other peptide assemblies to generate stiffer and more stable materials or to serve as a functional group and react easily to bind a variety of materials.

 

[197] NANOSCALE OXIDATION AND REDUCTION OF GRAPHENE

 

Wei-Yen Woon1, Jonathon White2

1 Dept of Physics; National Central University
2 Dept of Photonics Engineering; Yuan Ze University

The properties of Graphene, a unique two dimensional (2D) honeycomb lattice consisting sp2 bonded carbon atoms, is affected greatly by defects. On the one hand, the presence of defects can be seen as detrimental to the electrical performance of graphene, e.g., lowering electron mobility due to scattering, and thus something to be avoided. On the other hand, defects can be employed to tailor the electrical and chemical properties of graphene. Band gap opening and reactivity modification by functionalization with foreign atoms or structural defects are good examples of the utilization of defects in graphene. The controlled formation and elimination of these nanoscale defects is the topic of this paper. Scanning probe lithography (SPL) was employed under ambient conditions to locally oxidize CVD grown graphene. Subsequently, focused soft x-ray beams were used to reduce these sub-micron sized defects. Key aspects of the process were monitored using a combination of micro-Raman spectroscopy (μ-RS) and micro-x-ray photoelectron spectroscopy (μ-XPS). and various modes of atomic force microscopy (AFM). Locally areas of oxidation – whether protrusions or depressions –always had similar spectroscopic signatures, i.e, a reduced distance between defects (μ-RS), and the appearance of C-O and C=O bonds (μ-XPS). No evidence of the generation of sp3-type defects or C-OH bonds were found. After a subsequent reduction, the graphene film was found to be chemically identical (μ-XPS) but structurally different (μ-RS) from the original graphene. During reduction, the concentration of C-O and C=O bonds decreased uniformly as the C=C bonds concentration increased. The concentration of the C-C bond was found to initially increase and then decrease. Finally by modeling the dynamics of the C=O→C–O→C–C→C=C reduction process with four coupled-rate equations and three rate constants, the conversion from C–C to C=C bonds was found to be the limiting rate for the reduction process.

 

[201] EFFICIENT ELECTRODES VIA SELF-ASSEMBLY OF GOLD NANOSTRUCTURE POROUS NETWORK

 

Ahiud Morag1, Tatiana Golub2, James Becker3, Raz Jelinek4

1 Ben-Gurion University; Ilse Katz Institute for Nanoscale Science and Technology
2 Ben-Gurion University; Chemistry Department
3 Ben – Gurion University; Chemistry Department
4 Chemistry Department ; Ilse Katz Institute for Nanoscale Science and Technology

In this work we present a gold complex self-assembled to a mesh of nanowires which function as a porous electrode. We show that a simple chemical process for the removal of the complex ligands results in a highly conductive metallic gold electrode, which contain macro- and mesoporous structure. Using cyclic voltammetry, the specific surface area of the assembly was significant, measured to be around 4 m2/g. The surface area of the electrode is only depended upon the amount of gold complex used, and gold deposition could be done on any substance and surface geometries, making it easy to integrate the electrode in electronic device. This work present a new method for the fabrication of high surface area gold electrode which is robust, cheap, and show high performance in terms of active surface area.

 

[205] CHARGE TRANSPORT IN CU2S NANOCRYSTALS ARRAYS: EFFECTS OF CRYSTAL SIZE AND SURFACE COATING

 

Orian Elimelech1 Yehonadav Bekenstein, Kathy Vinokurov, Amitai Oren, Oded Millo, Uri Banin

1 Yehudit Birk 6; 12

Nanocrystals (NCs) can be used as building blocks for new structures and devices. Considering their chemical properties and the interactions between them, a well-organized nanocrystal array with the desired features can be designed. In addition, by tuning the properties of NCs arrays, applications in transistors, solar cells, sensors, and biosensor are enabled.
Copper (I) sulfide semiconductor have a wide spectrum of interesting properties, while one of them is related to being a mother compound to a larger family of ternary and quaternary Cu based semiconducting materials. NCs of such earth abundant materials are important in photovoltaic applications, considering their relevant band-gap values and their environmental compatibility.

In our work, we have studied how crystal size affects charge transport in Cu2S NCs arrays. Two NCs sizes were studied- 3 nm being within the quantum-confinement regime, and 14 nm, lacking quantum confinement. Additionally, the particles surface coverage was also modified with different ligands and the effect of their length on the charge transport mechanism was studied via temperature dependent conductance measurements. While in the 14nm NC based devices unique non-monotonic temperature dependence was observed, the 3nm based devices showed only thermally activated transport for all ligands. The difference was attributed to a cross-over from inter-particle hopping to intra-particle dominated transport as the ligand length increases. The presented new data has direct implication on the design of future Cu based NC devices.

Reference: Bekenstein, Y., Elimelech O., Vinokurov, K.,Millo, O., Banin, U., Charge transport in Cu2S nanocrystal arrays; a study of crystal size and ligand length, Zeitschrift für Physikalische Chemie (2014) doi: 10.1515/zpch-2014-0593

 

[211] NANOMANUFACTURING FOR DURABLE SUPERHYDROPHOBIC/ICEPHOBIC COATINGS

 

Joey Mead1, Tehila Nahum1, Artee Panwar1, Hanna Dodiuk2, Carol Barry1, Shmuel Kenig 2

1 University of Massachusetts Lowell; 1 University Avenue
2 Shenkar College; Anna Frank 12

Ice adhesion to surfaces is a significant problem with aircraft, ships, and power lines. The use of superhydrophobic surfaces for anti-ice properties have shown that they can reduce ice adhesion strength significantly compared to bare aluminum surfaces, but lack durability. Superhydrophobicity can be obtained by tailoring the chemistry and the roughness of the surface, mimicking the lotus leaf. Most superhydrophobic surfaces lose their roughness in harsh conditions and are unsuitable for practical applications. Typical superhydrophobic surfaces have micro-nano hierarchical roughness and hydrophobic chemistry. We have created several cost-effective, durable, and easily-manufacturable solutions to create icephobic surfaces on existing aircraft, ships, and power lines. The first approach uses particles in a polymer matrix to achieve superhydrophobic surfaces. The coating can be applied easily to large surfaces by spray coating and can be used with a variety of polymer matrices. A secondary top down approach can also be used for replicating nanostructured surfaces into thermoplastic films. Results for both approaches indicate the formation of superhydrophobic surfaces (contact angle >150° and sliding angle < 10°) with improved durability. The process can be scaled to a roll to roll process for large area applications.

 

[213] ELECTROCHEMICAL DEPOSITION OF NANOSTRUCTURES ON STRIPED PATTERNS OF BLOCK COPOLYMER TEMPLATE

 

Chanchayya Chandaluri1, Gilad Pelossof1, Ran Tel-Vered1, Roy Shenhar1, Itamar Willner1

1 The Hebrew University of Jerusalem; Givat Ram

Electrochemical Deposition of Nanostructures on Striped Patterns of Block Copolymer Template

Chanchayya Gupta Chandaluri, Gilad Pelossof, Ran Tel-Vered, Roy Shenhar* and Itamar Willner*
Institute of Chemistry, The Hebrew University of Jerusalem, Israel.

Patterned functionalized surfaces are of considerable interest due to a wide range of applications, from sensors and catalysts to photonic devices, which benefit either from the high surface area or from the nanoscale pattern. However, obtaining nano-patterned surfaces in a controlled fashion is not trivial. Block copolymers – polymers consisting of sequences of chemically distinct repeat units – give rise to useful nanoscale morphologies in thin films by phase separation, and thus provide a powerful platform for nano-patterning.
The poster describes our approach for obtaining nano-patterned functional coatings on electrodes using block copolymer films as masks. We show that chemical modification of one type of domains leads to substantially increased affinity of redox species to these domains. This enables selective electrodeposition of nanomaterials on these domains. Using this approach, we exemplify the ability to tune the wetting properties of the coated electrode by controlling the amount of deposited material on it, and demonstrate the crucial role of the nano-pattern.

 

[215] CELLULOSE COATED OIL-IN-WATER AND WATER-IN-OIL EMULSIONS REVEALED BY MOLECULAR DYNAMICS SIMULATIONS

 

Hitomi Miyamoto1, Dmitry Rein1, Chihiro Yamane2, Kazuyoshi Ueda3, Yachin Cohen1

1 Technion – Israel Institute of Technology, Department of Chemical Engineering; Technion City
2 Kobe Women’s University, Faculty of Home Economics; 2-1 Aoyama, Higashisuma Suma-Ku
3 Yokohama National University, Graduate School of Engineering; 79-5 Tokiwadai, Hodogaya-Ku

Encapsulation is an important technique which can provide many useful properties with small capsules. It is known that cellulose molecules dissolving in ionic liquid and cellulose in the amorphous state in hydro-gels regenerated from the solution form a stabilizing coating for oil-in-water and water-in-oil emulsions. However, the stability process and the coating state in molecular levels have not yet been fully understood. This study investigated the behavior of cellulose in oil-in-water and water-in-oil using molecular dynamics (MD) simulation.
Two different cellulose models were used respectively as initial models for oil-in-water and water-in-oil: one model consists of 16 separated chains of cellulose, and the other consists of cellulose mini-crystal constructed using the crystal coordinates of cellulose II. Octane molecules were used as the oil in this study. MD simulations were performed using CHARMM37 with CHARMM35 force field specifically developed for carbohydrates. The system was equilibrated at 300 K and 1 bar for 50 ns in NPT ensemble.
In both cellulose models for oil-in-water system, several oil droplets gathered to form one oil droplet at the beginning of simulations, and a single oil droplet apparently remained unchanged during 50 ns simulations. In the simulation model of 16 separated cellulose chains, the chains were gradually assembled with the progress of simulation time. Then, the octane droplet was observed to be surrounded by cellulose chains. These cellulose chains linked together by intermolecular hydrogen bonds. In the case of cellulose mini-crystal model for oil-in-water system, the structure of cellulose mini-crystal model was almost unaltered during the simulation. The cellulose chain on the corner along the (110) crystal plane which has a hydrophobic surface in the mini-crystal first interacts with octane molecules, and the cellulose chains along the plane then gradually interact with octane molecules during 50 ns simulations. In both cases of cellulose models for water-in-oil system, all water molecules interact with cellulose chains and they form hydrogen bonds at the beginning of simulations.

 

[225] SPACE DURABLE CNT-BASED NANOCOMPOSITES

 

Nurit Atar1, Eitan Grossman1, Irina Gouzman 1, Asaf Bolker1, Yael Hanein2

1 Space Environment Department; Soreq Nrc
2 Center for Nanoscience and Nanotechnology; Tel Aviv University

Polyimide (PI) is extensively used in various space applications due to its chemical and radiation resistance as well as its thermal stability. In particular, PI is commonly used as an exterior layer of thermal control blankets that are aimed to maintain a spacecraft’s instrumentation at working temperature. However, PI is degraded by electrostatic discharge (ESD) and atomic oxygen (AO), which are the dominant space environment hazards in geo-synchronous Earth orbit (GEO) and low Earth orbit (LEO), respectively. A common solution to this challenge is to coat the outer PI layer with indium tin oxide (ITO) which is AO resistant and electrically conductive and can therefore prevent local voltage build-up. However, ITO coatings are extremely brittle and cannot tolerate folding or bending when applied to flexible spacecraft surfaces. In this research, electrically-conductive PI-based composites for ESD protection were prepared by infiltration of PI-based blends into chemical vapor deposition (CVD)-grown carbon nanotube (CNT) sheets. AO durability was attained by the addition of polyhedral oligomeric silsesquioxane (POSS) to the PI precursor. This method prevents CNT agglomeration and degradation of the CNT properties. CNT-POSS-PI films with varying POSS content (0, 5, and 15 wt%) were prepared and exhibited homogeneous CNT distribution within the PI-based matrix. The composite films demonstrated sheet resistivities as low as 200 Ω/□, essentially preserving the original CNT sheet resistivity and well satisfying the ESD criterion. These resistivities remained essentially unchanged after mechanical manipulation, thermal cycling, and exposure to ionizing radiation. CNT-15%POSS-PI films exhibited an erosion yield of roughly one order of magnitude lower than that of pure PI films, and hence a 20 µm thick film could be functional for more than 10 years in the AO environment at LEO altitudes. CNT-PI and CNT-15%POSS-PI films are suggested for space applications such as the outer layers of spacecraft thermal blankets.

 

[227] CONTROL AND MANIPULATION OF QUANTUM SWITCHING AND SPIN-SPIN CORRELATIONS OF ENTANGLED NANOQUBIT PAIRS IN TB2 MOLECULAR MAGNET FOR INFORMATION PROCESSING

 

Oleg Farberovich1, Vyacheslav Gritzaenko2

1 Tel Aviv University; Tel Aviv University
2 Southern Federal University; Southern Federal University

Control and manipulation of quantum switching and spin-spin correlations of
entangled nanoqubit pairs in Tb2 molecular magnet for information processing

The problem of the spin switching speed of today magnetic logic and a magnetic memory devices into the terahertz regime underlies the entire field of information
processing. The physics of present-day devices imposes serious limitations on this technological transformation, so we must invent new paradigms based on
the quantum spin dynamics in the picosecond regime. This challenge could be met by a simulation of the quantum spin switching in a picosecond pulsed magnetic field.
We will discuss the relevance of the compound [Tb2Cl(HL4)2(H2L4)(py)2]. The studying of a possibility of the switching of the spin states and a controling of the entanglement would incredibly increase the amount of information storable with respect to current devices. In order to have a deeper understanding of fundamental features and a major control on technological aspects, the time-dependent spin dynamics constitutes the key point. The micromagnetic model describes appropriately the dynamics of the spin in a magnetic nanostructures. The spin dynamics are described by the Landau-Lifshitz-Gilbert (LLG) equation.
Spin systems are directly related to the entanglement between different spins, which can be employed in the field of quantum information processing. So far much of the work on correlations has focused on the static properties of equilibrium systems. It has been revealed that the way entanglement is created and how it propagates are important fundamental questions in quantum information theory. We will consider to what extent it is possible to control and manipulation of the correlation functions and entanglement by the pulse magnetic field. This may be relevant for the optimal creation of entanglement in spin systems, as well as contributing to a better understanding of how correlations are created in dynamical processes, something that can be tested experimentally in present setups.

 

[231] DIRECTIONAL COLLOIDAL SURFACE TREATMENT IN MICROFLUIDIC DEVICES

 

Eitan Edri1, Silvia Piperno2, Hagay Shpaisman3

1 Bar-Ilan University; Nano Technology Institute
2 Chemistry Department.; Bar Ilan University
3 Bar Ilan University; Nanotechnology Institute

Directional Colloidal Surface Treatment in Microfluidic Devices
Eitan Edri, Silvia Piperno, Hagay Shpaisman
The Nanotechnology Institute, Chemistry Department, Bar-Ilan University, Ramat-Gan, Israel

A novel concept is hereby demonstrated where directional surface treatment is performed on polymeric colloids by using a PDMS microfluidic device. In recent years, PDMS based microfluidic technology has become a great tool for complex micro-particle generation, thanks to its design flexibility. Therefore, we designed and fabricated a unique microfluidic device that can generate polymeric colloids by emulsification of a liquid monomer and treat their surface at specific locations. The treatment is performed by a small quantity of solution that is added to a specific location on the particle.
The novelty of this technique is in its potential to treat the same particle with different precursors in different directions resulting in the formation of patchy particles. These patchy particles will have the ability to bind to each other with a specific arrangement via different directional treatments. As the directionality could be easily programmable, numerous structures could be assembled.

 

[232] CHEMICAL EPITAXY AND REACTIVITY IN SOLUTION DEPOSITED PBS ON ZNTE FOR POTENTIAL USE IN SOLAR CELLS

 

sucheta sengupta1, Tzvi Templeman2, Yuval Golan1

1 Ben Gurion University of Negev; Marcus Family Campus
2 Ben-Gurion University ; Department of Material Engineering

Chemical epitaxy and reactivity in solution deposited PbS on ZnTe for potential use in solar cells

Sucheta Sengupta, Tzvi Templeman and Yuval Golan

Despite their promise, the efficiency of quantum dot solar cells is currently low (< 10%), where improved understanding of interfaces and contact layers adjacent to the quantum dots are presently a major limitation. The present work aims at optimizing the chemical bath deposition conditions for growing PbS thin films on MBE grown ZnTe for solar cell design. The morphology and properties of these films are found to be strongly affected by altering the solution pH, temperature and the reagent concentrations. A detailed structural analysis reveals the different orientation relationships present between the constituent layers and highlights the spontaneous formation of new, distinct intermediate layers during deposition. We also demonstrate that depending on the growth mechanism, the epitaxial informations are transmitted differently from one layer to the other under different conditions resulting in films with different orientations.

 

[245] TOWARDS ARTIFICIAL DNA MOLECULAR MOTORS THAT CAN WALK OVER MICROMETERS

 

Miran Liber1, Toma Tomov1, Roman Tsukanov2, Yaron Berger3, Eyal Nir1

1 Ben-Gurion University of the Negev; Ilse Katz Institute for Nanoscale Science & Technology
2 Ben Gurion University; Ilse Katz Institute for Nanoscale Science & Technology
3 Ben-Gurion University; Ilse Katz Institute for Nanoscale Science & Technology

Department of Chemistry and the Ilse Katz Institute for Nanoscale Science and Technology, BenGurion University of the Negev, Beer Sheva, 84105, Israel, miranl@post.bgu.ac.il, eyalnir@bgu.ac.il

Inspired by biological molecular motors such as Kinesin, which walk on microtubules over distance of several micrometers, our group develops artificial molecular motors made of DNA. We demonstrate striding of a bipedal walker over a distance of ~ 400 nm, in a back and forth fashion, on a 90 nm long track embedded into a DNA origami. However, to enable a unidirectional walking over long distances, it is necessary to attach several origami units in a control manner and with high yield and stability.
For that purpose we study different methods for connecting DNA origami tiles to create long tracks. The binding and unbinding reactions, yields and kinetics, were measured using single-molecule fluorescence spectroscopy, and binding methods and conditions were optimized to achieve best yield and stability.
Furthermore, by comparing the processivity of a motor striding on a single origami tile to that of an identical motor striding across the gap between two attached origami tiles we demonstrate that the walker does not dissociate when crossing between the origami. Moreover, we demonstrate that dozens of origami tiles can be connected to form a stable micrometer-long track. By these means we successfully demonstrate the necessary steps towards long range, robust and reliable artificial molecular motors and machines.

 

[249] SINGLE-STRANDED DNA DETECTION BY SOLVENT-INDUCED ASSEMBLIES OF A METALLO-PEPTIDE-BASED COMPLEX

 

Priyadip Das1, Meital Reches2

1 Institute Of Chemistry; The Hebrew University of Jerusalem
2 The Institute of Chemistry; The Center for Nanoscience and Nanotechnology

Single-stranded DNA Detection by Solvent-Induced Assemblies of a Metallo-Peptide-Based Complex
Priyadip Das1,2 Meital Reches1,2
1Institute of Chemistry, The Hebrew University of Jerusalem, 91904, Jerusalem, Israel.
2The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, 91904, Jerusalem, Israel

DNA detection is highly important for the sensitive sensing of different pathogenic bacteria and viruses. The major challenge is to create a sensor that can selectively detect very small concentrations of DNA without the need for amplification or complicated equipment. Different technologies such as optical, electrochemical and microgravimetric approaches can detect DNA fragments. Here we show, for the first time, the use of self-assembled nanostructures generated by a metallo-peptide as an optical sensing platform for DNA detection. The system can selectively detect single stranded DNA fragments by fluorescent measurements as it can discriminate between one mismatch and can perform even in the presence of other interfering proteins. This system may be useful in lab-on-a-chip applications. More importantly, the lower detection limit of this system for the HIV DNA was 1.4 nM, which is lower than those sensing system based on carbon nanostructures.

 

[254] HOLLOWING KINETICS OF AG-AU CORE-SHELL NANOPARTICLES CONTROLLED BY SHORT CIRCUIT DIFFUSION

 

Nimrod Gazit1, Eugen Rabkin1, Gunther Richter2

1 Department of Materials Science and Engineering; Technion
2 Thin Films; Max Planck Institute for Intelligent Systems

Hollow metallic nanoparticles attract great deal of attention due to their possible applications in various fields of nanotechnology (drug delivery, energy production and storage, catalysis, etc.). These particles have been fabricated in the past employing wet chemistry methods or/and Kirkendall effect during bulk interdiffusion in the core-shell nanoparticles. The latter process requires relatively high temperatures at which the bulk diffusion is active.
In this work we present a method of fabricating hollow Au nanoparticles based on surface and grain boundary diffusion, similar to the method proposed earlier for producing of hollow nanowhiskers . We produced an array of single crystal Ag nanoparticles on sapphire employing the solid state dewetting process of a thin Ag film deposited on sapphire substrate. A thin polycrystalline Au film was then deposited on the dewetted sample. During subsequent heat treatment at 170 °C the Ag atoms from the core of the core-shell Ag-Au nanoparticles diffused along the short-circuit diffusion paths (as shown by EFTEM analysis), leaving behind hollow Au nanoparticles. The hollowing kinetics that were studied by scanning electron microscopy and by a combination of focused ion beam with transmission electron microscopy are presented.

 

[259] METAL DIFFUSION ALONG THE FILM-SUBSTRATE INTERFACE IN PARTIALLY DEWETTED THIN FILMS

 

Hagit Barda1, Dor Amram1, Eugen Rabkin1

1 Department of Materials Science and Engineering; Technion

In a recent work [1], an indirect evidence for fast self-diffusion of Ni along the Ni-sapphire interface has been obtained. Polycrystalline Ni films of 40 nm in thickness were deposited on sapphire substrates. Solid state dewetting and grain boundary grooving in the films were studied at 700°C. An unusual flat topography of the grain boundary grooves and homogeneous thickening of the film were interpreted in terms of fast Ni self-diffusion along the film-substrate interface [1].
Based on these results, we propose a new method of measuring the metal heterodiffusion along the Ni-sapphire interface. We deposited a 4 nm thick Au film on partially dewetted Ni film which consists of holes (dewetted areas) surrounded by a bi-crystalline film. Afterwards, a diffusion annealing was performed at the temperature of 600°C, at which the morphology of the Ni film is highly stable. Gold atoms diffused from the edge of the holes along the Ni-sapphire interface, and the concentration decay in the direction from the hole edge to the unperturbed film was quantitatively characterized by high resolution transmission electron microscopy. Based on the suggested method, diffusion coefficient of Au along a film-substrate interface was determined.

[1] D. Amram, L. Klinger, N. Gazit, H. Gluska, E. Rabkin. ”Grain boundary grooving in thin films
revisited: the role of interface diffusion”, Acta mater. 2014; 69:386.

 

[265] GUIDED GROWTH OF HORIZONTAL CDSE NANOWIRES AND THEIR INTEGRATION INTO FAST VISIBLE-RANGE PHOTODETECTORS

 

erga shalev1, Eitan Oksenberg2, Ronit Popovitz Biro3, Katya Rechav3, Ernesto Joselevich4

1 Department of Materials and Interfaces ; Weizmann Institute of Science
2 Materials and Interfaces; Weizmann Institute of Science
3 Department of Chemical Research Support; Weizmann Institute of Science
4 Department of Materials and Interfaces; Weizmann Institute of Science

One-dimensional semiconductor nanostructures, such as nanowires (NWs), have attracted tremendous attention due to their unique properties and potential applications in nanoelectronics, nano-optoelectronics and sensors. The big challenge towards their integration into practical devices is their large-scale assembly with orientation control. Recently, our group has demonstrated a new growth approach for NWs: guided growth of horizontal NWs with controlled orientations via vapor-liquid-solid (VLS) process. The growth direction and crystallographic orientation are controlled by epitaxial relationship with the substrate, as well as by a graphoepitaxial effect of surface nano steps and grooves. The grown NWs location is determined by controlled prepositioning of a catalyst. Until now, our group succeeded to grow guided NWs of GaN, ZnO and ZnSe on sapphire, and GaN NWs on SiC and quartz. In order to reveal the full potential of this approach the guided growth process must be extended to a broader range of semiconductors with a variety of electrical and optical properties. In this work we report the guided growth of CdSe NWs on five different sapphire substrates. CdSe is a direct-bandgap II-VI semiconductor active in the visible range, which enables potential applications in optoelectronic devices. The guided NWs structure was characterized; the grown NWs were found to have wurtzite single crystal structure. Field effect transistors (FETs) were built to examine the NWs electronic properties. Their optoelectronic properties were also studied revealing promising results. The guided CdSe NWs have fast rise and decay times, less than the best published for CdSe NWs, which is essential for optoelectronic applications.

 

[268] EFFECT OF BLEND SOLVENTS ON THE STABILITY OF PTB7:PCBM-BASED SOLAR CELLS

 

laura ciammaruchi1

1 Ben Gurion University of the Negev; Department of Solar Energy and Environmental Physics

EFFECT OF BLEND SOLVENTS ON THE STABILITY
OF PTB7:PCBM-BASED SOLAR CELLS
Laura Ciammaruchi1,Gloria Zanotti1,3,Francesca Brunetti2,Eugene A.Katz1,4and Iris Visoly-Fisher1,4
1.Department of Solar Energy and Environmental Physics,Ben Gurion University of the Negev,Sede Boker, Israel.
2.Dept. of Electronics Engineering,Università di Tor Vergata,Rome, Italy
3.CNR–ISM Via Salaria km29.500,Monterotondo Scalo(Rm),Italy
4.Ilse Katz Institute for Nano-scale Science and Technology,Ben Gurion University of the Negev, BeerSheva,Israel
Low-band-gap organic photovoltaic(OPV) reached significant photo-conversion efficiencies(PCEs) and the current research faces two fundamental challenges:combining adequate lifetime with low manufacturing impact on the environment.8.7%PCE was reported for an inverted OPV cell based on PTB7:PCBM blended in o-xylene(XY),eliminating the polluting chlorine in chlorobenzene(CB) commonly used as the blend solvent[1].Since the solvent choice determines the photo-active layer morphology hence charge carrier mobility,it may also affect the degradation patterns [2].We studied solvent-related degradation in inverted PTB7:PCBM-based cell blended in CB or XY.Optical, morphological and electrical investigations point to a solvent-driven vertical stratification in the photoactive layer,affecting the degradation mechanisms.PTB7-rich bottom layers were assumed in CB-cells,while PCBM-rich top layers were found inXY-cells.XY-cells showed superior stability compared to CB-cells during storage in the dark and exposure to natural sunlight.CB-cell degradation was demonstrated mostly by Voc decrease due to morphology coarsening,while XY-cell degradation was expressed in Jsc decrease, probably due to chemical degradation ofPTB7 at the interfaces.However,XY-cells were less stable under concentrated sunlight[3],due to the increased UV illumination intensity.The reduced stability is attributed to residual XY in the photoactive layer,which is UV-sensitive,and is enhanced by the top Ag contact which acts as a photocatalyst.We conclude that the improved morphology stability,combined with a more efficient solvent evaporation process and appropriate UV filtering,vote in favor of the use of more environmentally friendly,non-chlorinated solvents such as XY.

1. Susanna, G., et al., Solar Energy Materials and Solar Cells, 2015, 134: 194-198
2. Takayuki, K., et al., Japanese Journal of Applied Physics, 2014, 53.2S: 02BE06.
3. I. Visoly-Fisher, et al., Sol. Ener. Mater. & Sol. Cells 2015, 134: 99–107

 

 

 

 

 

 

[284] SINGLE MOLECULE AND NANOPARTICLE ABSORPTION SPECTROSCOPY

 

eitam vinegrad1

1 Tel-Aviv University; –

Single molecule and nanoparticle absorption spectroscopy
Eitam Vinegrad1, Ori Cheshnovsky2
1) School of Physics, Tel-Aviv University, 2) School of Chemistry, Tel-Aviv University 69978 Tel Aviv, Israel
Single molecule spectroscopic detection in fluorescent microscopy is well established now. The technique highly relies on the fact that it is practically background free. Extensive research pertaining to the dynamics of single molecules is based on single-molecule spectroscopy. However, not all molecules of interest fluoresce. In many cases, the introduction of fluorescent marker molecule is required in order to investigate or monitor the required dynamics. In other cases, the spectroscopic properties of non-fluorescent molecules cannot be studied with this technique. In the last few years, few techniques capable of single molecule detection via optical absorption have emerged. Due to the fact that the area of diffraction limited laser spot is of the order of magnitude of 0.1 µm2 and the absorption cross section of molecules is of the order of 10-7 µm2, detection capability of extremely small optical densities is required in these methods.
In this work, we present a new approach in measuring the absorption of single nano objects. We use a super-continuum laser (Fianium) and a circular variable filter to choose the wavelength of operation. The absorption detection is then carried out by balanced photodiodes aimed to suppress the laser noise.
Scientific goals:
A. Spectroscopic characterization of specially designed Si/Ge core shell nanowires (fabricated by our collaborators in F. Patolsky’s lab), which according to theoretical predictions by A. Zunger are characterized by a direct band gap.
B. Chirality measurements of single nano objects both of artificially designed chiral nano objects and chiral nanoparticles (with our collaborators in G. Markovich’s lab).
We will present our experimental methodology as well as preliminary results on the absorption of several nanoparticle systems, as well as chirality measurements of artificial nano objects.

 

[287] STUDY OF NANOLAYERS IN REVERSE LIT CONFIGURATION FOR PEROVSKITE SOLAR CELLS ON METAL SUBSTRATES

 

Maria del Carmen Lopez Luna1, S. Zaka Ahmed2, David Pickup2

1 Dyesol UK Ltd. ; 48 Grafton Street M13 9xx
2 Dyesol UK Ltd.; 48 Grafton Street M13 9xx

STUDY OF NANOLAYERS IN REVERSE LIT CONFIGURATION FOR PEROVSKITE SOLAR CELLS ON METAL SUBSTRATES

María C. López, S. Zaka Ahmed, David Pickup.
Dyesol UK Ltd. 48 Grafton Street M13 9XX Manchester UNITED KINGDOM
mdelcarmen@dyesol.com

Perovskite Solar Cells (PSCs) have attracted great interest in the scientific community due to their ease of preparation and high power conversion efficiencies. Thanks to their ultra-low weight architecture and low cost manufacturing techniques, metal based PSCs could find applications on the roofs of supermarkets, warehouses, etc. PSC could act as power plants for self-energy generating buildings with off-grid or feed-in configurations.
The implementation of PSC on metal has several challenges since metals are not transparent and the light must get in through the opposite side. There is a sacrifice in performance due to reverse lit configuration since the transmittance is lower through the semi-transparent electrode and HTM/ETM than through FTO glass side.
We have calculated the loss in performance due to reverse lit configuration using glass substrates with semi-transparent gold-coatings. Before reaching the capping layer, light must pass through the thin gold coating (12-15 nm) and the HTM, which have a transmittance of 63% and 94.5% respectively in the visible light wavelength range. Consequently there is a direct lost in light ingress of 42.5% that is equivalent to a decrease in photo-generated current in the same ratio. Actually the experimental decrease in current is ≈46.7%. This might be attributed to the fact that physical phenomena taking place in reverse and normal lit configuration are not exactly the same. In reverse lit light interacts first with the capping layer whereas in normal lit it interacts first with the infiltrated perovskite in the mesoporous titania layer.

Acknowledgments
The research leading to these results has received funding from the European Union Seventh Framework Programme under DESTINY project (grant agreement 316494).

 

[290] FLEXIBLE CARBON NANOTUBES BASED ACTUATORS

 

Ela Sachyani1

1 The Hebrew University ; The Hebrew University

Flexible Carbon Nanotubes Based Actuators

Ela Sachyani, Michael Layani and Shlomo Magdassi

Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel

Actuators are devices that react by movement to a given trigger such as electric field, magnetic field, heat or light. Actuators can be used in a variety of fields such as mechanical devices, sensing, and soft robotics.
The work presented here is focused on printed electrothermal Carbon Nanotubes (CNT) based actuators. A typical electrothermal actuator structure is a double layer containing CNT electrode and a polymer. CNTs are flexible, electrically and thermally conductive, and therefore are excellent candidates for flexible and stretchable electrothermally triggered actuators.
Three main types of CNT based actuators are presented. The first type is a U-shaped CNT layer deposited on top of polyimide substrate. The actuation occurs due to a deference in thermal expansion coefficient (CTE) between the two materials. Once voltage is applied, the CNT layer heats up and the actuator bends towards the material that has smaller thermal expansion. The second type is a U-shaped CNT layer deposited on a Shape Memory Polymer (SMP) [1]. The SMP is a material that can recover its permanent shape after temporary shape deformation. Here, the CNT acts as an electrical heater that reverts the SMP back to its original state. The third type of CNT actuator is based a combination of the first and second type of actuators.
The future goal is to fabricate 3D printed actuators for the soft robotic applications.

[1] Zarek, M.; Layani, M.; Cooperstein, I.; Sachyani, E.; Cohn, D.; Magdassi, S. “3D Printing of Shape Memory Polymers for Flexible Electronic Devices”, Advanced materials 2015, DOI: 10.1002/adma.201503132.

 

[291] SOLID PHASE HYDROGENATION OF PHENYL ACETYLENES BY HYDROGEN SPILLOVER: THE IMPACT OF HYDROGENATION PRESSURE AND SPILLOVER MEDIA ON PRODUCT DISTRIBUTION

 

Adi Mary Akiva-Moyal1, Eyal Ben-Yehuda1, Michael Gozin2, Ofra Paz-Tal1, Svetlana Pevzner1

1 Nuclear Research Center of Negev; Chemistry Department
2 School of Chemistry; Ttel Aviv University

Hydrogenation in the solid phase is important in “green” synthesis, for the limited use of solvents and for the use of solid, recyclable catalysts. This reaction is also significant in the field of hydrogen scavenging, where it is necessary to remove the hydrogen gas in order to prevent the risks of explosion, metal corrosion or embrittlement, due to its reaction with hydrogen.
The catalytic solid-phase hydrogenation of two short phenyl-acetylenes was studied.
Solid samples of the acetylenes with a Pd/C catalyst were hydrogenated to various degrees at different initial pressures; the partially hydrogenated samples were separated from the catalyst and analyzed by gas-chromatography, to quantify the reaction products.
Comparison of the products’ distribution at different hydrogenation pressures and at different stages of the hydrogenation reaction, gives insight into the mechanism of hydrogenation in the solid phase.
We claim that the hydrogen travels from the metal catalyst to the substrate by a mechanism known as hydrogen spillover, that is, the hydrogen migrates across the catalyst’s carbon support.
The results of the study show that the reaction intermediates prefer syn addition; and the amounts of these products are greatly affected by the hydrogenation pressure.
Addition of carbon nanotubes to the solid reaction media was previously shown to increase the reaction rate. In this study, analysis of the influence of carbon nanotubes (CNTs) on the products’ distribution shows trends similar to the hydrogenation pressure increase. We believe that the CNTs, which are known as spillover agents, facilitate the migration of hydrogen from the metal catalyst to the solid substrate and increase the distance that activated hydrogen species can travel. This phenomenon could be described as reducing the energy barrier for the diffusion of the hydrogen species.
In summary, by studying the product distribution of the solid phase hydrogenation at different pressures with the addition of spillover agents, one gains insight into the reaction mechanism.

 

[298] INVESTIGATION OF THE WET ETCHING OF GE2SB2TE5 THIN FILMS FOR NON-VOLATILE PHASE CHANGE MEMORY APPLICATION

 

Svetlana Nemtseva1, Maria Mikhailova1, Petr Lazarenko1, Alexey Sherchenkov1, Sergey Kozyukhin2, Sergey Timoshenkov1

1 National Research University of Electronic Technology; Bld. 1, Shokin Square 124498
2 Kurnakov Institute of General and Inorganic Chemistry of Russian Academy of Science; 31 Leninsky Prospect 119991

Non-volatile phase-change memory (PCM) on the basis of Ge2Sb2Te5 (GST225) is one of the main candidates for the next generation of memory technology.
High operation rate (less than 100 ns), cyclability (>108), and possibility of using the standard processes of microelectronics are the main advantages of PCM technology. However, optimization of PCM-technology is required, particularly, of the formation of nanoscale programmable cell area. Therefore development of the etching process of GST225 thin films for the fabrication of PCM cell is needed.
Amorphous thin films were deposited on SiO2 substrate by the thermal evaporation in vacuum. The thicknesses of the films were approximately 200 nm.
Optical microscopy (Carl Zeiss Axiovert 40 MAC) and atomic force microscopy (NT-MDT SolverPro) were used to investigate morphology of thin films.
The average roughness of the film surface was 0,224 nm.
It was established that (20 vol.%) solution of HCl, H3PO4, H2SO4, did not etch as-deposited GST225 film, and according to AFM the change of of the surface was not observed. However, adding of the H2O2 (30 vol.%) to acid inert solution allowed to obtain the active etchant.
Treatment of the film in H2O2 at room temperature did not lead to the etching of the film. However, increasing of the temperature up to 30-70 °C was accompanied by the modification of the GST225 layer morphology.
One of the important photolithography operations is removing of the photoresist in DMFA (C3H7NO) solution. It was found that using of DMFA did not lead to the change in the surface morphology of GST225 film. According to ACM the average surface roughness is comparable with that of the initial morphology, so it can be used in photolithography processes.
As a result, it has been found that the Ge2Sb2Te5 thin film is easily etched with HNO3 and: H2SO4, H3PO4, HCl solutions added with H2O2.
This work was supported by the Ministry of Education and Science of Russian Federation (FPP, project ID: RFMEFI57814X0085).

 

[299] TRANSPARENT POLYCRYSTALLINE ND:YAG PROCESSED BY HIGH PRESSURE SPARK PLASMA SINTERING (HPSPS) TECHNIQUE

 

Maxim Sokol1, Sergey Kalabukhov1, Vladimir Kasiyan1, Moshe Dariel1, Frage Nachum2

1 Ben-Gurion University of the Negev; P.O.B. 653
2 Bgu; P.O.B. 653

High pressure spark plasma sintering (HPSPS) was employed to fabricate polycrystalline Nd:YAG specimens with desired functional properties. Specimens fabricated under a uniaxial pressure of 300 MPa at 1300°C at a heating rate of 50°C/min and holding time of 60 min displayed nano-structure and elevated mechanical properties, including resistance to thermal shock. Optical properties (i.e. spectral transmittance, fluorescence emission spectra and fluorescence lifetime) of the HPSPS-processed specimens were close to those obtained with specimens fabricated by conventional sintering procedure. Remarkable differences in threshold power and laser slope efficiency were found and attributed to the variance in Nd concentration in the specimens tested. The results of the present study indicate that the low cost and time-saving HPSPS process can be used for the fabrication of polycrystalline Nd:YAG specimens with the combination of the optical and mechanical properties suitable for laser applications.

 

[301] POROUS COLLOIDS GENERATED BY SPINODAL DECOMPOSITION

 

Elad Hadad1

1 Bar Ilan University Ramat Gan, 5290002; Bar Ilan University Ramat Gan, 5290002

Porous Colloids Generated by Spinodal Decomposition
Elad Hadad , Hagay Shpaisman
The Chemistry Department, Institute for Nanotechnology and Advanced Materials
Bar-Ilan University, Ramat-Gan, Israel

Spinodal decomposition (SD) is a mechanism by which a one phase solution separates into different phases with distinctly different chemical compositions, thus forming a unique porous structure. These structures have been extensively studied in thin films and bulk. Here we present a novel method where porous colloids are fabricated by SD separation. We study how the interface between the continuous phase and the dispersed phase undergoing SD influences the forming structure.
A mixture of a UV curable adhesive (NOA 81) with a co-solvent (acetone) and non-solvent (water) serves as the dispersed phase. By UV irradiation this phase undergoes photo-polymerization induced SD phase separation. We find that for maintaining SD the most suitable continuous phase requires minimal interaction with the dispersed phase (fluorocarbon oil).
We gain control over the porous structure of the colloids by controlling the dispersion method, UV intensity, temperature and the composition of the dispersed phase. Further study over the properties of these new porous colloids will follow.

 

[312] INDUCTION OF CHIRALITY AND CHIROPTICAL ACTIVITY IN INORGANIC NANOCRYSTALS USING BIOMOLEUCLES

 

Assaf Ben-Moshe1, Gil Markovich2

1 School of Chemistry; Tel-Aviv University
2 School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences; Tel-Aviv University

Chirality is a geometric property of objects that cannot be superimposed onto their mirror images. Chiral structures also give rise to unique chiroptical effects when interacting with polarized light. These properties are fundamental in biomolecular systems, and chiroptical spectroscopy is often used for their characterization. The aim of this work is to introduce chirality into inorganic nanosystems, in order to add an interesting degree of complexity and unravel new effects. Two different approaches for induction of chiral phenomena in inorganic nanocrystals are presented. In the first type of systems, chiral molecules are used to indcue chiroptical effects in the electronic transitions of achiral nanocrystals. This effect is interesting for fundamental studies of exciton/plasmon- molecular level interaction. However, it is generally very weak. More recently, we introduced the concept of enantioselective synthesis of intrinsically chiral inorganic nanocrystals, which leads to more pronounced effects. Many inorganic materials such as quartz, mercury sulfide and tellurium crystallize in chiral space groups with a chiral lattice. Biomolecules can be used to induce enantioselectivity in the nucleation and growth of nanoscrytals of these materials. For the case of tellurium, we show that crystal growth in the presence of the small peptide, glutathione, results in nanocrystals where the atomic scale lattice chirality translates to the overall shape chirality on a 100 nm scale. This is a unique example for a colloidal chemistry approach for self assembling inorganic nanocrystals, which exhibit chirality at two size hierarchies. These systems may be useful for applications in metamtaerials fabrication, asymmetric catalysis, sensing and optical devices. On a more fundamental level, these are excellent model systems for studies of chiral crystallization and separation, and the interaction of chiral biomolecules with chiral crystals. The possible role of chiral inorganic crystals and surfaces in the evolution of biomolecular homochirality has been considered by many researchers. Here it is demonstrated that the opposite effect, of biomoleucles affecting chiral inorganic crystallization, is also intriguing.

 

[317] UTILIZATION OF SELF-ASSEMBLED SHORT PEPTIDES NANOSTRUCTURES

 

Lihi Adler-Abramovich1

1 School of Dental Medicine; and the Department of Molecular Microbiology and Biotechnology

Utilization of Self-Assembled Short Peptides Nanostructures
Lihi Adler-Abramovich
Department of Oral Biology, The Goldschleger School of Dental Medicine, and the Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Tel Aviv 69978, Israel.

LihiA@tauex.tau.ac.il

Organic and inorganic self-assembled tubular nanostructures were suggested to have key potential in nanotechnological devices and applications. Several studies have shown the possible use of bionanometric material for applications ranging from molecular electronic to drug delivery. Short peptide motifs can efficiently self-assembles into discrete, well-ordered nanostructures.
In the current research, using different microscopy and spectroscopy tools, we describe a remarkable thermal and chemical stability of the aromatic-dipeptide-nanostructures [ADNS]. Furthermore, we studied the peptide nanotubes and nano-spheres mechanical properties and found that the peptide nanospheres have high Young’s modulus of up to 275 GPa, which places these peptide nano-assemblies among the stiffest bio-inspired materials presently known.
A limiting factor in the utilization of the ADNS system was the ability to spatially control the assembly process. Various methodologies were developed for the horizontal and vertical alignment of the ADNS and for their patterning. We used the inkjet technology for the application of ADNS on non-biological surfaces. Additionally, vapor-deposition technique was used to form vertically aligned nanotubes arrays that were later utilized for the formation of super-hydrophobic surface, sensitive sensors and ultracapacitors for energy storage applications.
In summary, the remarkable physical properties and the ability to control the assembly of the ADNS suggests their application in conventional microelectronic and microelectromechanics processes, as well as fabrication into functional nanotechnological devices.

 

[321] SYNTHESIS AND PROPERTIES OF NANOCRYSTALLINE Π-SNS – A NEW CUBIC PHASE OF TIN SULPHIDE

 

Ran Eitan Abutbul1, Elad Segev1, Leila Zeiri2, Vladimir Yazrasky1, Guy Makov3, Yuval Golan4

1 Ben-Gurion University of the Negev; Ilse Katz Institute for Nanoscale Science and Technology
2 Ilse Katz Institute for Nanoscale Science and Technology; Chemistry Department
3 Department of Materials Engineering; Ilse Katz Institute for Nanoscale Science and Technology
4 Ben Gurion University of Negev; Marcus Family Campus

Synthesis and Properties of Nanocrystalline π-SnS – A New Cubic Phase of Tin Sulphide

Ran E. Abutbul†‡, Elad Segev‡, Leila Zeiri‡#, Vladimir Ezersky‡, Guy Makov†‡ and Yuval Golan†‡
†Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
‡Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
#Chemistry Department, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel

We report on the synthesis of the newly discovered cubic phase of tin sulfide π-SnS and compare its properties to the well-known phase of tin sulfide, -SnS. Shape control was achieved by variation of synthesis parameters, resulting in cubic, rhombic dodecahedral and tetrahedral shapes of the π-SnS nanoparticles. X-ray diffraction provided authentication of the proposed model and refined determination of the lattice parameter a=11.595 Å. Raman spectroscopy showed substantial shift towards higher energies and peak splitting for π-SnS. Optical absorption spectroscopy indicated an indirect band gap of 1.53 eV, in good agreement with density functional theory (DFT) calculations indicating a band gap greater than that of -SnS. DFT total energy calculations show that the π-SnS phase is energetically similar to α-SnS, and significantly more stable than the hypothetical ideal rocksalt structure of SnS.

 

[324] SYNTHESIS AND PROPERTIES OF NANOCRYSTALLINE Π-SNSE – A NEW CUBIC PHASE OF TIN SELENIDE

 

Ran Eitan Abutbul1, Elad Segev1, Leila Zeiri2, Vladimir Yazrasky1, Guy Makov3, Yuval Golan4

1 Ben-Gurion University of the Negev; Ilse Katz Institute for Nanoscale Science and Technology
2 Ilse Katz Institute for Nanoscale Science and Technology; Chemistry Department
3 Department of Materials Engineering; Ilse Katz Institute for Nanoscale Science and Technology
4 Ben Gurion University of Negev; Marcus Family Campus

Synthesis and Properties of Nanocrystalline π-SnSe – a new cubic phase of Tin Selenide

Ran E. Abutbul†‡, Elad Segev‡, Leila Zeiri‡#, Vladimir Ezersky‡, Guy Makov†‡ and Yuval Golan†‡
†Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
‡Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
#Chemistry Department, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel

We report on a new binary phase in the tin mono-selenide system, Pi-SnSe, which was obtained as cube shaped nanoparticles. The structure and atomic positions was deduced using X-ray diffraction and Rietveld refinement (a0 = 11.939Å, No. 198), and showed a structure which is analogous to the recently reported cubic phase of SnS (a0 = 11.595Å, No. 198). The new cubic SnSe phase was further characterized by Raman and optical absorption spectroscopies. The optical band gap was assessed to be indirect, with Eg=1.28eV (in the near infrared), compared to Eg=0.9eV (indirect) and 1.3eV (direct) eV for the conventional orthorhombic phase of SnSe. DFT calculation has been applied in order to validate the phase stability.

 

[326] CHEMICAL BATH DEPOSITION OF NANO COLUMNAR THIN FILMS OF PBSE

 

Tzvi Templeman1, Nizan Maman2, Amir Tal3, sucheta sengupta4, Alexander Rabkin5, Michael Shandalov6, Iris Visoly-Fisher2, Gabby Sarusi3, Yuval Golan4

1 Ben-Gurion University ; Department of Material Engineering
2 Swiss Institute for Dryland Environmental and Energy Research; Swiss Institute for Dryland Environmental and Energy Research
3 Ilse Katz Institute for Nano-Scale Science and Technology; Department of Electrooptics Engineering
4 Ben Gurion University of Negev; Marcus Family Campus
5 Ilse Katz Institute for Nano-Scale Science and Technology; Ilse Katz Institute for Nano-Scale Science and Technology
6 Department of Physics; Department of Physics

Chemical Bath Deposition of Nano Columnar Thin Films of PbSe
Tzvi Templeman1,2, Nitzan Maman4, Amir Tal1,3, Sucheta Sengupta1, Alexander Rabkin1, Michael Shandalov5, Iris Visoly-Fisher1,4, Gabby Sarusi1,3 and Yuval Golan1,2
1Ilse Katz Institute for Nano-scale Science and Technology, Ben Gurion University of the Negev, Israel
2Department of Materials Engineering, Ben Gurion University of the Negev, Israel
3Department of ElectroOptics Engineering, Ben Gurion University of the Negev, Israel
4Department of Solar Energy and Environmental Physics, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Israel
5Department of Physics, Nuclear Research Center Negev, P.O. Box 9001 Beer Sheva, Israel

The present study describes the morphology and growth kinetics of nano-columnar PbSe films grown on GaAs(100) substrates using chemical bath deposition (CBD). Although columnar film growth is well established in chemical and physical vapor deposition, this is not the case in CBD, where the two main mechanisms which describe film growth are the ion-by-ion (IBI) and cluster growth mechanisms. In this work we present a previously unreported mechanism in CBD which leads to columnar growth.
Films were investigated using XRD, HRSEM and TEM. The initial nucleation density is controlled by bath parameters, specifically temperature and complex/cation ratio. Growth is interrupted in lateral x-y dimensions and enhanced along z, resulting in columnar morphology. Well-defined orientation relations were established with the substrate, and interestingly, neighboring columns were found to be in alternating twinning relations. A clear transition to IBI occurs as growth proceeds and complex/cation ratio increases, a transition which can be prevented by replenishing bath concentrations.
Current-sensing AFM was used to measure the transport properties and lateral electronic homogeneity. The nano-column boundaries showed insulating behavior while grain interior shows good conduction along the z direction, which is advantageous for the use of these films as SWIR absorbers in upconversion night vision devices.

 

[335] CHEMICAL BATH DEPOSITED PBS(TH) THIN FILMS FOR INFRARED DETECTION

 

Nitzan Maman1

1 Bgu; Bgu

Chemical Bath Deposited PbS(Th) Thin Films for Infrared Detection
Nitzan Maman1 , Tzvi Templeman2,3, Amir Tal2,4, Michael Shandalov5, Sucheta Sengupta2, Alexander Rabkin2, Yuval Golan2,3 , Gabby Sarusi2,4 and Iris Visoly-Fisher1,2
1Department of Solar Energy and Environmental Physics, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Israel
2Ilse Katz Institute for Nano-scale Science and Technology, Ben Gurion University of the Negev, Israel
3Department of Materials Engineering, Ben Gurion University of the Negev, Israel,
4Department of ElectroOptics Engineering, Ben Gurion University of the Negev, Israel
5Department of Physics, Nuclear Research Center Negev, P.O. Box 9001 Beer Sheva, Israel

The electronic and optical properties of PbS(Th) films with nano-spherical morphology deposited on GaAs(100) substrates were studied in order to determine their potential use as SWIR absorber material for upconversion night vision devices. The films were grown by chemical bath deposition during which small concentrations of Th+4 cations were incorporated, The films demonstrated quantum confinement effects, in which the band gap increases with Th at%.
FTIR transmission measurements showed a strong absorption band at 1.8 µm for films containing ~8 at% Th. Several absorption states in the forbidden gap were monitored as a function of post-deposition thermal treatment parameters such as temperature, duration and atmosphere.
Photoconduction measurements were performed on these films in the dark and under SWIR illumination ( nm, 5mW) as a function of film thickness and different thermal treatments. The resistivity of the films was found to decrease by more than 50% under SWIR illumination compared to dark resistivity.

 

[341] HYBRID LEAD SULFIDE QUANTUM DOT- LEAD HALIDE PEROVSKITE BASED SOLAR CELLS

 

Daniel Amgar1

1 The Hebrew University of Jerusalem; The Hebrew University of Jerusalem

Hybrid Lead Sulfide Quantum Dot- Lead Halide Perovskite Based
Solar Cells
Daniel Amgar, Lioz Etgar
The Institute of Chemistry, Casalli Center for applied chemistry
The Hebrew University of Jerusalem

The research concentrates on the development of novel solar cells. The motivation is creating renewable energy from the sun as an endless energy source by fabricating high efficiency and low cost solar cells. Photovoltaic cells are made of a variety of materials and architectures and this work will be involved with third generation solar cells, while working on hybrid perovskite nanoparticles – PbS quantum dots based solar cells. Perovskite has the chemical formula of ABX3 when A is a cation, B is a metallic bivalent cation and X is a halide. The use of all kinds of perovskite for photovoltaic applications derives from its great advantages as a light absorbing material what can improve cells performance. The perovskite is characterized with a band gap suitable for the visible region of the solar spectrum, low bonding energies, high charge carrier mobilities and large diffusion lengths. PbS quantum dots have the ability to absorb NIR photons through size-tuning of their bandgap and show potential for multiple exciton generation. In addition, both materials allow affordable and easy solution process ability.
The main goal is combining both materials while using the special properties of the perovskite and the QDs in order to utilize the energy of photons from all across the solar spectrum as much as possible and as a result, developing hybrid cells integrating these two materials.

 

[342] WS2 NANOTUBES AS TEMPLATES FOR FUSION OF METALLIC NANOPARTICLES

 

Priyadarshi Ranjan1, Ronit Popovitz Biro2, Ifat Kaplan-Ashiri1, Michal Lahav3, Reshef Tenne4, Milko E. van der Boom3

1 Weizmann Institute of Science; 234 Hertzl
2 Department of Chemical Research Support; Weizmann Institute of Science
3 Weizmann Institute of Science; 234 Hertzl St.
4 Department of Materials and Interfaces; Weizmann Institute of Science

WS2 nanotubes as templates for fusion of metallic nanoparticles
Priyadarshi Ranjanϯ,§, Ronit Popovitz-BiroƮ, Ifat Kaplan-AshiriƮ, Michal Lahavϯ,
Reshef Tenne§, and Milko E. van der Boomϯ

ϯDepartment of Organic Chemistry, §Department of Materials and Interfaces, ƮDepartment of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel 7610001

Nanotubes of WS2 (INT-WS2) have been uniformly decorated by gold nanoparticles of 5 nm diameter, silver nanoparticles of 17 nm diameter, and palladium nanoparticles of 2 nm diameter. This process is likely driven by lattice matching of these crystalline materials. The stepwise decorations of INT-WS2 by the metallic nanoparticles can be used to tune the optical properties of the ensembles. Remarkably, thermolysis of our hybrid ensembles results in the fusion of the particles on the surface of INT-WS2. Fusion of the gold nanoparticles results in the formation of a single nanodecahedron particle on the nanotube. Follow-up electron microscopy studies provided fundamental insights into the nanoparticle fusion processes.

 

[345] VT-STM STUDIES OF SUPERPARAMAGNETISM AND THE VERWEY TRANSITION IN FE3O4 NANOCRYSTALS

 

Amir Hevroni1, Gil Markovich2

1 School of Chemistry; Tel Aviv University
2 School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences; Tel-Aviv University

In the first project, the magnetization dynamics of individual magnetite nanocrystals was probed by variable temperature magne¬toresistive scanning tunneling microscopy, in which a magnetoresistive junction is formed between the substrate and the magnetic par¬ticle under study. When the temperature was tuned close to the magnetization blocking of a superparamagnetic particle, the slow magnetization switching of the particle caused fluctuations in the tunnel current passing through the particle, which appeared as telegraph noise in current vs. time measurements. Analysis of the current fluctuations yielded estimates for the small local magnetic field sensed by the particle, its magnetic anisotropy energy, and a low limit for its spin-polarization degree. For one of the particles, the spin-polarization appeared to be as high as 90%.
In the second project, the temperature evolution of the density of states in, co-precipitation-synthesized, ~10 nm magnetite nanocrystals around magnetite’s metal-insulator transition temperature (Verwey transition) was probed using variable temperature scanning tunneling spectroscopy. The transition was observed as a significant change in the electronic structure around the Fermi level, with an apparent band-gap of ~140-240 meV appearing below the transition temperature, and a pseudo-gap of ~75±10 meV appearing above it. Since the particles studied are only few unit cells in size, it is quite a surprise that such a sharp transition was observed in view of the significance of long-range charge ordering in the low-temperature phase. The transition temperature was invariably observed around 101±2K for different nanocrystals, as opposed to 123K typically found in stoichiometric bulk crystals. This suggests that the lowering of the transition temperature is an intrinsic finite size effect, probably due to the presence of the surface. The transition was also shown to be hysteretic with supercooling of 5-8K.

 

[348] CARBON NANOTUBE – QUANTUM ROD LIGHT INDUCED ENERGY TRANSDUCTION FOR RETINAL STIMULATION

 

Gur Lubin1

1 Tel Aviv University; Tel Aviv University Center for Nanoscience and Nanotechnology

Carbon nanotube – quantum rod light induced energy transduction for retinal stimulation
Gur Lubin 1,2, David Rand 1,2, Lilach Bareket Keren 1,2, Jacob Ben-Dov 1,2, Nir Waiskopf 3,4, Dorit Raz Prag1,2, Soumyendu Roy 1,2, Moshe David Pur 1,2, Uri Banin 3,4, Ori Cheshnovski 1,5, Yael Hanein 1,2
1Tel-Aviv University Center for Nanosciecne and Nanotechnology, Tel Aviv, Israel
2School of Electrical Engineering, Tel Aviv University, Israel
3Institute of Chemistry, The Hebrew University of Jerusalem, Israel
4Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Israel
5School of Chemistry, Tel Aviv University, Israel

Retinal degeneration is a common cause of age and non-age related blindness. Electrical stimulation of a degenerated retina has the capacity to elicit visual responses in the brain, and restore vision. Here we report on light induced activation of a blind chick embryo retina in-vitro using a novel bio-mimetic carbon nanotube (CNT) – semiconductor quantum rod (QR) based platform. This result highlights the CNT-QR nanocomposites’ potential to enable high resolution, wire free activation of neurons, addressing the main setbacks of today’s state of the art retinal prosthesis technology. To gain a better understanding of the underlying mechanism of the light harvesting in these composite films, we present an optical investigation into the light response of various QR – metal hybrids. Fluorescence quenching, indicated by a shortening of the QR fluorescence lifetime, together with photo-electrical measurements, point to an efficient energy harvesting mechanism in the CNT-QR hybrids. Combining this mechanism with the excellent performance of CNT mesh electrodes for electrical interface with neurons, we were able to achieve light induced neuronal activation in ambient light intensities.

Bareket, Lilach, et al. “Semiconductor Nanorod–Carbon Nanotube Biomimetic Films for Wire-Free Photostimulation of Blind Retinas.” Nano letters 14.11 (2014): 6685-6692.

 

[349] THE EFFECT OF CITRATE AS A CO-COMPLEXANT DURING CHEMICAL BATH DEPOSITION OF PBS THIN FILMS

 

Maayan Perez1, sucheta sengupta2, Yuval Golan2

1 Ben Gurion University; Iki
2 Ben Gurion University of Negev; Marcus Family Campus

The effect of citrate as a co-complexant during chemical bath deposition of PbS thin films
Maayan Pereza, Sucheta Senguptaa and Yuval Golana
a. Department of Materials Engineering, and the Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.

Tri sodium citrate (citrate) has been commonly used as a co-complexing agent during chemical bath deposition to improve film quality and control grain size, yet its precise role has not been elucidated to date. In this study, we have focused on the role of citrate in chemically deposited PbS thin films. Citrate effectively complexes the lead cation in solution, thereby decreasing growth rate and inducing growth in the cluster mechanism. This was monitored in real time using laser light-scattering and UV-Vis absorption spectroscopy which quantitatively confirmed the retarded PbS formation in the cluster mechanism in the presence of citrate. Nanocrystalline PbS films formed in presence of citrate show quantum confinement effects with blue shifted optical properties compared to the bulk, adding an important path for controlling film properties towards future infrared optoelectronic applications.

 

[354] CONDUCTIVE COPPER COMPLEX INKJET INK WITH SELF REDUCTION MECHANISM FOR FLEXIBLE ELECTRONICS

 

Yousef Farraj1, Shlomo Magdassi2

1 Casali Center for Applied Chemistry; Chemistry
2 The Hebrew University of Jerusalem; Chemistry

Conductive copper complex inkjet ink with self reduction mechanism
for flexible electronics

Yousef Farraj, Shlomo Magdassi
Casali Center for Applied Chemistry, Institute of Chemistry and Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel

In the past decade, the fabrication of low-cost flexible electronics by printing has gained a lot of interest in devices such as circuit boards, RFID tags, touch screens and flexible displays. In particular, inkjet printing of metals for conductive patterns is a promising approach for producing low cost electronic devices on flexible substrates. Several reports on printing metallic nanoparticles inks, usually silver, at low temperature, were reported recently. However, their high cost limits the fabrication of low cost plastic devices and therefore, there is an unmet need to find a replacement inks based on low cost metals. Among metals, copper is the most promising candidate, having the second lowest resistivity, and its cost is 90 times lower than that of silver. Nevertheless, the main challenge with copper-based inks is to prevent the oxidation of the copper nanoparticles before and after printing.
Here we describe the formation and utilization of a metal ink based on copper complexes that undergoes decomposition and conversion to copper nanoparticles at low temperatures (below 150 °C). Therefore this ink enables printing conductors on heat sensitive plastic substrates such as PET and PEN. The conversion to copper can be done either by conventional heating or by other methods as flash sintering, and lasers. The ink is stable in ambient conditions for prolonged periods, without any deterioration of its functionality, as compared to what is usually encountered in nanoparticles based inks, such as aggregation and formation of copper oxide.

 

[357] BUFFER LAYER ASSISTED GROWTH OF METAL NANOPARTICLES IN TITANIA THIN FILMS FOR PHOTOCATALYSIS APPLICATIONS

 

Liat Zilberberg1, Serge Mitlin2, Shankar Harisingh3, Micha Asscher1

1 Faculty of Science; The Institute of Chemistry
2 Faculty of Science ; The Institute of Chemistry
3 Faculty of Science ; Chemistry

Buffer Layer Assisted Growth of metal Nanoparticles in Titania Thin Films
for Photocatalysis Applications
L. Zilberberg, S. Mitlin, H. Shankar and M. Asscher
Institute of Chemistry, Edmund J. Safra Campus,
The Hebrew University of Jerusalem, Jerusalem 91904, Israel

Developing materials with improved photocatalytic activity is important for light energy conversion and storage within chemical bonds. Here we present a new type of hybrid films of silver nanoparticles (AgNPs) embedded within TiOx (x≤2) to approach this goal, introducing visible light absorption via surface-plasmon excitation of the AgNPs. Silver nanoparticles were prepared by an ultra-high vacuum (UHV) based Buffer Layer Assisted Growth method. The titania films as a substrate and protective layers were grown by the Reactive Layer Assisted Deposition (RLAD) technique, in both cases amorphous solid water (ASW) was the buffer material. The thin titania films and the AgNPs were ex-situ characterized by UV-VIS, micro-Raman, XRD, XPS, SEM and TEM techniques. The titania protective layers on top of the silver particles were found to introduce a dielectric environment for the AgNPs, leading to a significant red-shift of their plasmon resonance from 460 to 530 nm, in addition to avoiding oxidation of the small nanoparticles. Photo-induced activity of these hybrid films has been tested following the degradation of methylene blue (MB) in aqueous solution under both UV and visible pulsed laser irradiation. Preliminary results have shown photo-catalytic activity of the RLAD titania film with only marginal influence due to the presence of the AgNPs. However, it seems that the irradiation causes partial degradation of the AgNPs and lead to doping of the TiO2, which yields absorption tail in the visible region. In order to observe the plasmon enhancement we try to get energy overlapping between the plasmon and the oxide. For this purpose hybrid materials containing aluminum nano particles were prepared and examined.

 

[361] HIERARCHICALLY-STRUCTURED NANOCOMPOSITE FILMS ASSEMBLED ON TOPOGRAPHICALLY PATTERNED SUBSTRATES

 

Elisheva Michman1, Meirav Oded1, Ernesto Joselevich2, Mark Schvartzman3, Roy Shenhar4

1 Institute of Chemistry; The Hebrew University of Jerusalem
2 Department of Materials and Interfaces; Weizmann Institute of Science
3 Department of Materials Engineering; Ben-Gurion University of the Negev
4 The Hebrew University of Jerusalem; Givat Ram

Hierarchically-structured nanocomposite films assembled on topographically patterned substrates

Elisheva Michman1, Meirav Oded1, Ernesto Joselevich2, Mark Schvartzman3 and Roy Shenhar1
1Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
2Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, Israel
3Department of Materials Engineering, Ben-Gurion University of the Negev, Beer Sheva, Israel

Co-assembly of block copolymers and nanoparticles in composite thin films has become a leading bottom-up method of nanoparticle organization for functional devices. The effects of nanoparticle size, surface chemistry, and filling fraction on the location of nanoparticles within block copolymer domains is the subject of considerable ongoing investigation. However, the nanocomposite films in most of these studies lack the long-range order required for various technological applications. Whereas directed self-assembly using lithographically-defined substrate patterns has been shown as a powerful approach for aligning block copolymer domains along macroscopic coordinates, the directed self-assembly of nanocomposite films is so far rather unexplored.
We studied the assembly of thin films of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) block copolymers with and without gold nanoparticles on topographically patterned silicon substrates. The patterned substrates, featuring stripes of different widths and separation distances, were obtained by nanoimprint lithography. Interestingly, different local morphologies of the block copolymer were observed on the stripes and inside the gaps. Even more elaborate structures were observed in nanocomposite films, where the nanoparticle filling fraction has been found to be a determining factor in the order and morphology of the film. The poster will present the different morphologies observed and will explore possible explanations for their occurrence.

Example of a hierarchical nanocomposite morphology obtained on a topographically patterned substrate.

 

[362] CHEMICAL BATH DEPOSITION AND CHEMICAL EPITAXY OF CADMIUM SULFIDE THIN FILMS ON GAAS SUBSTRATE

 

Ofir Friedman1, Yuval Golan2

1 Ben-Gurion University of the Negev; Marcus Family Campus
2 Ben Gurion University of Negev; Marcus Family Campus

Chemical Bath Deposition and Chemical Epitaxy of Cadmium Sulfide Thin Films on GaAs Substrate

Ofir Friedman and Yuval Golan
Department of Materials Engineering, and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel

Chemical bath deposition (CBD) from solution offers a simple and cost-effective route for the fabrication of high quality semiconductor thin films, without the need for high deposition temperatures, stringent vacuum or plasma generators. Chemical epitaxy is particularly advantageous for obtaining monocrystalline thin films with well-defined orientation relations with the monocrystalline substrate. Notably, understanding the chemical and physical mechanisms governing chemical epitaxy can allow us to predict and control the orientation of thin films.
Cadmium sulfide (CdS) is a II-VI semiconductor with a wide and direct band gap of 2.42 eV. In this work, we have studied the microstructure and morphology of CdS films chemically deposited on GaAs(100). The deposition of CdS on GaAs was found to be strongly influenced by several parameters, including the order of reagents addition, reagent concentrations, pH, time and temperature. The CdS films grown on GaAs(100) showed a ; orientation relationship, providing the first reported evidence for chemical epitaxy in CBD CdS on GaAs(100).

 

[364] PRINTING OF COPPER PATTERNS ON 2D AND 3D OBJECTS YIELDING 50% BULK CONDUCTIVITY BY USING A SELF-REDUCING PRECURSOR

 

Yitzchak (Isaac) Rosen1, Shlomo Magdassi2

1 Casali Center for Applied Chemistry; Center for Nanoscience and Nanotechnology
2 Casali Center of Applied Chemistry; The Hebrew University of Jerusalem

Printing of copper patterns on 2D and 3D Objects Yielding 50% Bulk Conductivity by Using a Self-Reducing Precursor

Yitzchak (Isaac) Rosen and Prof. Shlomo Magdassi (HUJI)

Fabrication of devices by printing conductive interconnections on plastic substrates is of growing research interest. Therefore, several approaches for the sintering of metallic nanoparticles (NP), mainly silver were recently developed. However, the high cost of silver limits commercial use and therefore inks with other metals, such as copper, are required. Inks containing copper NPs suffer from stability problems, as the NPs are quickly oxidised, and so lose their conductivity. Therefore, there is an unmet need for a copper ink with a low sintering temperature.
Two concepts for forming copper conductive patterns were examined. The first approach is based on using a new dispersion ink that contains nano and sub-micron copper salt particles which are stable to oxidation. This ink was used as a Metal Organic Decomposition ink which is printed and then heated to induce thermal decomposition. During decomposition, the organic matter is broken down to volatile species while reducing the copper, thus leaving a Cu° pattern.
Another approach is based on the use of copper precursors in a transfer printing process that results in 50% bulk copper conductivity. Two steps are involved in the process. In the first step, the mirror image of a desired pattern is printed with the ink on a “donor substrate”. In the second step, this pattern decomposes by heating under N2 gas, and copper is transferred to a close by “acceptor substrate” through the gas phase. This approach can be used to pattern 2D substrates and performed onto 3D objects with several advantages; it is non-contact, eco-friendly, low cost, and a dense layer of copper is obtained leading to low resistivity.

“Printing of Self-Reducing Copper Precursor Yielding 50% Bulk Conductivity on 2D and 3D Objects” Advanced Materials Interface, 2015.

 

[365] LARGE SCALE COLLOIDAL PRODUCTION OF ULTRATHIN TWO-DIMENSIONAL (2D) BI2SE3 TOPOLOGICAL INSULATORS AND ITS DOPED ANALOGUES

 

pradipta sankar maiti1

1 Ben-Gurion University of the Negev; Department of Chemistry

Title
Large Scale colloidal production of ultrathin two-dimensional (2D) Bi2Se3 topological insulators and its doped analogues
Abstract
Ultrathin 2D Bi2Se3 nanostructures with few quintuple layers (QL) have emerged new exciting material due its topological insulator properties. The surface conductivity of these exotic materials is highly influenced by their layer thickness. In contrast to tradition MBE techniques, these structures can be prepared in solution phase in large scale with controlled and uniform thickness (~5 -10 QL) that is small compared to their lateral dimensions. Furthermore, doping these topological insulators with materials like Mn2+, Sb+3 can alter their chemical potential which also provides us additional degree of freedom which can be used to tune their properties by varying their composition. These doped-Bi2Se3 nanostructures can open new possibilities in device engineering in the field of spintronics and low-energy electronics.
Here, we are going present the colloidal synthesis of the ultrathin 2D Bi2Se3 nanosheets as well as their physiochemical properties. We will be showing the effect of magnetic and non-magnetic doping on the shape, size, optical and magnetic properties of these 2D nanostructures. Structural, compositional and optical characterizations are going to be presented using SEM, TEM, UV-visible absorption, powder X-diffraction (PXRD), XPS and SQUID measurements.

 

[366] HIGH PERFORMANCE 3D PRINTING OF HYDROGELS BY WATER-DISPERSIBLE PHOTO-INITIATOR NANOPARTICLES

 

Amol Pawar1, Gabriel Saada1, ido cooperstein2, Liraz Larush1, Shlomo Magdassi1

1 Casali Center of Applied Chemistry; The Hebrew University of Jerusalem
2 The Hebrew University of Jerusalem; Casali Institute for Applied Chemistry

Title: High performance 3D printing of hydrogels by water-dispersible photo-initiator nanoparticles

Authors: Amol A Pawar, Gabriel Saada, Ido Cooperstein, Liraz Larush and Shlomo Magdassi
Affiliation: Casali Center for Applied Chemistry, Institute of Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel

Application of 3D printing using photo-polymerization based processes for making hydrogels and devices for tissue engineering applications is restricted by the lack of water soluble photo-initiators. A new approach to enable rapid 3D printing of hydrogels in aqueous solutions is presented, based on UV curable inks containing nanoparticles of highly efficient, but water insoluble photoinitiator. TPO (Ethyl-2,4,6 trimethylbenzoyl-phenyl phosphinate) is a water-insoluble, crystalline photo-initiator used to facilitate photo-polymerization through UV curing. The present work aims to prepare amorphous, water dispersible TPO nanoparticles by rapid conversion of volatile microemulsions droplets. The extinction coefficient of the new water dispersible nanoparticles of TPO is more than 300 times larger than the best commercially available and mostly used water soluble photoinitiator. The TPO nanoparticles absorbs significantly in the range of 385 – 420 nm, making them suitable for use in commercially available, low cost LED based digital light processing 3D printers. The polymerization rate at this range is very fast, and enables 3D printing that otherwise is impossible to perform without adding solvents. Such water dispersible photo-initiator nanoparticles opens many opportunities in enabling rapid 3D printing of structures prepared in aqueous solutions, while bringing environmental advantages by using low-energy curing systems and by avoiding the need for solvents.
Keywords: 3D printing; hydrogels; photoinitiator; TPO; UV curing

 

[371] AN ULTRASENSITIVE METHOD FOR PROTEIN AND DNA DETECTION AT THE SINGLE MOLECULE LEVEL

 

Haya Dachlika1

1 Hebrew University of Jerusalem; Hebrew University of Jerusalem

An ultrasensitive method for protein and DNA detection at the single molecule level
One of the central challenges of humanity is the prediction, prevention, and early detection of diseases. A possible path to meet this challenge is the development of highly sensitive methods for early detection of disease biomarkers and proteins. The proposed method is based on conjugation of the ligands to metal nanoparticles (NP) and binding of the conjugated complex to the macromolecule. Later, the formed structures will be characterized using electron microscopy (EM) that enables ultrasensitive detection of the NP dimers.
The first and simple model system was based on NP-DNA conjugates. In this model system, gold nanoparticles (GNP) with different sizes, conjugated to two different DNA oligonucleotides. The NP-DNA conjugates were connected through hybridization by a third DNA oligonucleotide that is representing the target macromolecule, and dimers were formed. The dimers are the only NPs in the sample solution that are connected to the third DNA. Thus it is possible to identify and quantify them even at low abundance by EM. As a protein model system we used ASPP2 protein that has known separated binding sites for various proteins and peptides. Here, two different peptides were conjugated to GNPs with different sizes. The ASPP2 protein was then bound to the GNP-peptide conjugates and GNP dimers were formed. The formed structures, in which each biomarker is flanked by two easily recognizable NPs (a dimer) will be detected and characterized using EM.

 

[377] CREATION OF HIGH DENSITY ENSEMBLES OF NITROGEN-VACANCY CENTERS IN NITROGEN-RICH TYPE IB NANODIAMONDS

 

Jui-Hung Hsu1

1 Department of Materials and Opto-Electronic Science; National Sun Yat-Sen University

We present the fabrication and analysis of fluorescent nano-diamonds (FNDs) containing high density ensembles of negatively-charged nitrogen vacancy (NV-) color centers in diamond nanoparticles of various sizes (10–100 nm) using nitrogen-rich type Ib diamond powders as the starting material. The nanodiamonds were prepared by ball milling of microdiamonds, in which the density of neutral and atomically dispersed nitrogen atoms ([N0]) was measured by diffuse reflectance infrared Fourier transform spectroscopy. A systematic measurement of the fluorescence intensities and lifetimes of the crushed monocrystalline diamonds as a function of [N0] indicated that [NV-] increases nearly linearly with [N0] at 100–200 ppm. The trend, however, failed to continue for nanodiamonds with higher [N0] (up to 390 ppm) but poorer crystallinity. We attribute the result to a combined effect of fluorescence quenching as well as the lower conversion efficiency of vacancies to NV- due to the presence of more impurities and defects in these as-grown diamond crystallites. We demonstrate that it is possible to improve the brightness of FNDs with the [N0] increasing from 100 ppm to 200 ppm for crushed monocrystalline diamonds. Our results indicate that through careful control of the radiation damage conditions and proper choice of the diamond materials, increase of [NV-] above 10 ppm in 10 nm FND particles is practical.

 

[383] NANOPOROUS SINGLE CRYSTALS OF GOLD

 

Maria Koifman1, Leonid Bloch2, Manfred Burghammer3, Yaron Kauffmann2, Alexander Katsman2, Boaz Pokroy1

1 Department of Materials Science and Engineering, Technion − Israel Institute of Technology; Russell Berrie Nanotechnology Institute, Technion − Israel Institute of Technology
2 Department of Materials Science and Engineering, Technion − Israel Institute of Technology; Nr
3 European Synchrotron Radiation Facility; Nr

Single crystals in nature often demonstrate fascinating intricate porous morphologies rather than classical faceted surfaces. We are growing such crystals, drawing inspiration from biogenic porous single crystals. Here we show that nanoporous single crystals of gold can be grown with no need for any elaborate fabrication steps. These crystals are found to grow following solidification of a eutectic composition melt that forms as a result of the dewetting of nanometric thin films. We also present a kinetic model that shows how this nano-porous single-crystalline structure can be obtained, and which allows the potential size of the porous single crystal to be predicted. Retaining their single-crystalline nature is due to the fact that the full crystallization process is faster than the average period between two subsequent nucleation events. Our findings clearly demonstrate that it is possible to form singe crystalline nano porous metal crystals in a controlled manner. We also show that nanoporous single crystal prepared by eutectic composition demonstrate superior thermal stability as compared to their counterpart nanoporous gold prepared by dealloying, which is essential for catalysis.

 

[392] SOFT-SUBSTRATE-RIGID-FEATURE (SSRF) NANOIMPRINT LITHOGRAPHY

 

Liran Menahem1, Mark Schvartzman2

1 Department of Materials Engineering, Ilse Katz Institute for Nanoscale Science and Technology.; P.O. Box 653, Beer-Sheva 84105, Israel.
2 Department of Materials Engineering; Ben-Gurion University of the Negev

SOFT-SUBSTRATE-RIGID-FEATURE (SSRF) NANOIMPRINT LITHOGRAPHY
Liran Menahem, Dr. Mark Schvartzman
Department of Materials Engineering, Ilse Katz Institute for Nanoscale Science and Technology.
Ben-Gurion University of the Negev.
P.O. Box 653, Beer-Sheva 84105, Israel.

Two existing approaches of Nano Imprint Lithography (NIL) are defined by the mold material. In hard NIL, molds are made of rigid materials, such as Silicon or Quartz. These molds offer nanometer resolution and superior pattern fidelity, .however, they are extremely sensitive to surface contamination and defects. Alternatively, soft molds are made of cast elastomers (Poly(Dimethylsiloxane) – PDMS). They offer highly conformal contact and low contaminant sensitivity, and can imprint curved surfaces, however, their compressibility makes the pattern features deform, buckle, or collapse, resulting in pattern distortion and limited resolution
Here, we introduce a novel hybrid Soft-Substrate-Rigid-Feature (SSRF) nanoimprint mold based on soft substrate with rigid relief features. It combines the advantages of each of the traditional molding approaches, and at the same time overcomes their drawbacks: (i) High pattern fidelity and small feature size as offered by hard molds; and (ii) low sensitivity to defects and patterning curved substrates as offered by soft molds.
We produced SSRF molds by electron-beam lithography (EBL) of Hydrogen Silsesquioxane (HSQ) on a sacrificial substrate, and transferred the obtained HSQ features to PDMS substrates. Anti-adhesive coating usually used for hard Si molds was successfully applied on SSRF mold, and found to be essential for the mold durability. The molds were used for nano imprint of UV-curable resists. Using ultra-high resolution EBL we produced SSRF mold with sub-20 nm pattern. In summary, we have demonstrated an innovative concept of robust, high-quality, and cost-effective nanoimprint, which will open a pathway to numerous applications impossible up today.

Key Words: Electron Beam Lithography, High Resolution.

Additional suggested keywords: Nano Imprint, Soft lithography.

 

[396] TWEAKING ELECTROCHEMICAL PROPERTIES OF CARBON NANOTUBE BY SURFACE MODIFICATION

 

krishna kant1

1 Institute of Biochemistry, Food Science, and Nutrition; The Hebrew University of Jerusalem,

Tweaking electrochemical properties of carbon nanotube by surface modification
K.Kant1,2, M. Alsawat1, T. Altalhi1 and D. Losic1

1School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia
2Institute of Biochemistry, Food Science, and Nutrition Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel

Exceptional properties of carbon nanotubes (CNTs), including electrical conductivity, mechanical strength, smooth hydrophobic graphitic walls, electronic, thermal properties, have led to the development of membrane based separation technologies. Nano-porous alumina membranes (NPAM) is been used as template to fabricate CNTs membranes with controllable nanotube dimensions by catalyst-free CVD approach. In this work, we focused on the study of electrochemical properties of CNT/NPAM by the use of electrochemical impedance spectroscopy (EIS). The specific objectives were to explore the surface modifications of CNTs and their electrochemical properties which can be used as a strategy for electrophoretic and potential based separation of charged molecules. NPAM was prepared by a two-step anodization process using 0.3 M oxalic acid as electrolyte at 0°C. CNTs were fabricated inside the pores of the template of NPAM by catalyst-free CVD approach. The chemical modification of CNTs (Mo-CNTs) was performed by hydrogen peroxide (H2O2) treatment in order to introduce oxygen-containing group, mainly hydroxyl, in the inner surface of CNTs. The morphology and chemical composition of the prepared CNT and Mo-CNT membranes were characterized using scanning electron microscopy (SEM) transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The electrical properties were characterized by a four-point electrode impedance system in the frequency range from 1 Hz to 1MHz using various concentrations of NaCl electrolyte. The transport properties of CNT/NPAM and Mo-CNT/NPAM were characterized using two model molecules (uncharged and charged). Our results confirmed that simple chemical oxidation process of CNTs can be used to tune their conductivity and interfacial properties which can be used to control their transport and chemical selectivity characteristics.

 

[397] PROTEIN MAPPING ON ICE SURFACE BY USING QUANTUM DOTS

 

krishna kant1

1 Institute of Biochemistry, Food Science, and Nutrition; The Hebrew University of Jerusalem,

Protein mapping on Ice surface by using quantum dots
Krishna Kant and Ido Braslavsky

Institute of Biochemistry, Food Science, and Nutrition, Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel

Water and ice are two most abundant materials available on the earth and it’s been always in interest of human being to understand the exceptional properties of the ice/water interface. It is important for the microscopic study of macromolecules in field of biology and organic chemistry. Therefore the surface of ice has been investigated by use of various fluorescent techniques. The characterization of ice surface by fluorescent microscopy offers the possibility to examine the ice surface and protein binding efficiency under numerous conditions at high resolution. However, molecular level observation of ice crystal surfaces is very challenging. The short life time of fluorescent molecule and low brightness are major challenge to do imaging over the ice surface. The use of anti-fading agents make this process complicated and originality of the ice sample is been sacrificed. Herein we are proposing the use of hydrophilic CdTe quantum dots (2 nm) which can be easily tagged with the anti-freezing proteins and bind on the ice surface easily. The local heating of the quantum dots over the ice surface can be a problem when it been hit by laser beams. To overcome the problem, employing anti freezing protein (AFP) is useful which have properties to sustain the thermal hysteresis by +2 оC. These proteins have been evolved in a variety of cold adapted organisms such as fish, insects, bacteria, and plants. Antifreeze proteins are one class of the ice-binding proteins which have capability to control growth of ice-crystal. In this proposed research, a new approach for exploring the molecular activity of AFPs on ice surface will be developed to address open questions of protein interaction with ice surface and its arrangement over the ice crystal.

 

[398] SYNTHESIS OF AIR-STABLE COPPER PARTICLES WITH SILVER NANOSHELL BY TRANSMETALLATION METHOD

 

Anna Pajor-Swierzy1

1 The Hebrew University of Jerusalem; Casali Center of Applied Chemistry

Synthesis of air-stable copper particles with silver nanoshell by transmetallation method
Anna Pajor-Świerzy, Alexander Kamyshny, Shlomo Magdassi
Casali Center of Applied Chemistry, Institute of Chemistry, The Hebrew University of Jerusalem, Israel

Currently, most conductive nanoinks for printing various electronic devices are based on silver nanoparticles (NPs). However, large-scale production of printed electronic devices requires low-cost inks, in which silver as a conductive functional material is replaced by much cheaper base metals. The most suitable metal is copper with conductivity of about 95% of that for silver. The specific challenge while utilizing copper particles is their oxidation at ambient conditions. The most effective approach to obtaining stable copper particles is coating them with a protective nanoshell of noble metals, i.e. formation of bimetallic core-shell particles (core@shell).
In this research, stable to oxidation Cu particles, were synthesized by formation of Ag nanoshell on their surface with the use of three-step process: (1) formation of dispersion of Cu particles from Cu(NO3¬)¬2¬ as a precursor and a reducing agent, sodium formaldehyde sulfoxylate, in the presence of a polymeric stabilizer, polyacrylic acid sodium salt; (2) removing an excess of reducing agent by washing the Cu dispersion with a solution of ascorbic acid; and (3) transmetallation (galvanic displacement) reaction between silver ammonia complex (AgNO¬3¬-NH¬3¬) and Cu atoms on the surface of Cu particles resulting in formation of Cu@Ag particles. The structure of the Cu@Ag NPs was analyzed and supported by UV-VIS spectra, X-ray Diffraction (XRD) and SEM electron mapping.
At the next stage, Cu@Ag particles were used for formulation of conductive inks. To optimize wetting properties, various co-solvents were added to ink formulation. The most promising results were obtained using DPMA (35%) and TEGO WET KL 245 as wetting agents (0.5%). To obtain conductive metallic structures, we used thermal sintering by heating the metallic patterns deposited on a glass. After sintering at 250 °C for 15 min. the resistivity value was found to be 6.8·10¬-4 Ω∙cm.

 

[400] USING VERTICALLY ALIGNED ZINC OXIDE NANOWIRE ARRAYS AS A TEMPLATE FOR METAL SULFIDE NANOTUBE ARRAYS

 

Michael Volokh1

1 Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology

USING VERTICALLY ALIGNED ZINC OXIDE NANOWIRE ARRAYS AS A TEMPLATE FOR METAL SULFIDE NANOTUBE ARRAYS
Michael Volokh, Mahmud Diab, Kobi Flomin, Pazit Rukenstein, and Taleb Mokari*
Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel.

High surface area semiconductor nanostructures are important constituents in energy-related applications such as photovoltaics, water splitting, catalysis, and batteries. We use a simple atmospheric-pressure chemical vapor deposition (CVD) system to control the filling and coating of ZnO nanowire (NW) array templates with metal-sulfide shells to create hybrid nanostructures.1 The reactants of the CVD are single-source precursors (SSP). Using different SSPs allowed us to synthesize multi-component structures such as NWs coated with alloy-shell
or multi-shell structures.
Since the zinc oxide is an amphoteric material, applying a basic or acidic environment, allows the dissolution of the ZnO NW template. We used this phenomenon to create different vertically aligned nanotube (NT) arrays such as CdS, ZnS, and CdS-ZnS. The resulting NTs are high-quality polycrystalline nanostructures.
Herein, we present the synthesis and
structural characterization of the different structures. Furthermore, an electrochemical characterization proves the increased surface area of the discussed NTs.

1. Volokh, M.; Diab, M.; Magen, O.; Jen-La Plante, I.; Flomin, K.; Rukenstein, P.; Tessler, N.; Mokari, T. Coating and Enhanced Photocurrent of Vertically Aligned Zinc Oxide Nanowire Arrays with Metal Sulfide Materials. ACS Appl. Mater. Interfaces 2014, 6, 13594–13599.

 

[404] NANODIAMOND-BASED DIAGNOSTIC SYSTEM FOR ULTRASONIC MONITORING OF WATER QUALITY

 

Abba Priev1, Yechezkel (Chezy) Barenholz2

1 Laboratory of Liposomal and Membrane Research; Hebrew University – Hadassah Medical School
2 Institute of Medical Research Israel-Canada (Imric), ; The Hebrew University of Jerusalem

Nanodiamond-based Diagnostic System for Ultrasonic Monitoring of Water Quality

Abba Priev and Yechezkel Barenholz
Laboratory of Liposomal and Membrane Research, IMRIC, Hebrew University – Hadassah Medical School, Jerusalem, Israel

A nanoparticle-based diagnostic kit for real-time ultrasonic monitoring of pathogens and toxins in water has been developed. The device employs a dual mode of operation of high-intensity acoustic waves for concentration of the pathogens in a central node, and low-intensity acoustic waves for precise compositional analysis of nanoparticles (NPs) after their binding to pathogens or toxins. Acoustic acceleration of the immunoassay brings about separation between free and bound antigen in less than one minute when high-density NPs such as nanodiamonds are used. At present, it takes at least 24 hours to detect the presence of pathogens (e.g. coliforms in water reservoirs) by microbiological assays.
We are exploring NP-based diagnostic kits for ultrasonic continuous monitoring of antigens and other biological agents. We have improved sensitivity and reduced the time required for the biological agents’ detection by monitoring biological agents in the sample by capturing and further acoustic analysis of the NP immune complexes. Acoustic pressure is used for capturing and separating the biological agent-NP complexes from the free NPs, and the measurements of acoustic properties are used for precise analysis. The developed NP-based systems for acoustic identification of bacteria or toxins uses Abs immobilized on the NP which interact with the pathogen in the online flow system. High accuracy for sound velocity measurements (up to 0.0002%) and sound attenuation (of about 0.2%) have been used for testing of different toxins and bacteria. Comparative analyses of the ultrasonic method with standard immunoassay techniques have produced linear calibration curves for major components, with correlation coefficients higher than 0.98. It is thus possible to monitor the toxins, viruses and bacteria in water and also to measure physical properties such as conductivity, viscosity, compressibility and density.

 

[414] GRAPHENE QUANTUM DOTS PRODUCED BY MICROFLUIDIZATION

 

Matat Buzaglo1, Michael Shtein2, Oren Regev3

1 Department of Chemical Engineering, Ben Gurion University; Ilse Katz Institute for Meso and Nanoscale Science and Technology, Ben-Gurion University
2 Ben-Gurion University of the Negev; Ilse Katz Institute for Meso and Nanoscale Science and Technology, Ben-Gurion University
3 Department of Chemical Engineering, Ben-Gurion University of the Negev; Ilse Katz Institute for Meso and Nanoscale Science and Technology, Ben-Gurion University

Graphene Quantum Dots Produced by Microfluidization
Matat Buzaglo,1, Michael Shtein, 2 and Oren Regev 1, 2*
1Department of Chemical Engineering and 2Ilse Katz Institute for Meso and Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
The unique physical properties of graphene quantum dots, including their controllable photoluminescence, flexible structure, biocompatibility and photostability, make them highly desirable for novel applications, such as flexible photovoltaics and bioimaging.
However, the commercialization of these next–generation quantum dots is limited because their production is highly complex and costly. Here, we present for a first time, a purely mechanical method for top-down fabrication of graphene quantum dots.
During a microfluidizer-based “top-down” fabrication, millimeter-sized graphite flakes are fragmented into zero-dimensional nano-sized dots due to high shear rates (>107 sec-1) generated by pressurizing the graphite-aqueous suspension through micro-sized channels. The as-prepared graphene quantum dots are non-functionalized and exhibit excitation-independent photoluminescence.
This facile, environmentally friendly, and scalable method provides an ideal framework for substantial progress toward large-scale production and commercialization of graphene quantum dots-based applications.

 

[415] THE CRITICAL ROLE OF NANOTUBE SHAPE IN CEMENT COMPOSITES

 

Roey Nadiv1, Michael Shtein2, Maor Refaeli3, Alva Peled3, Oren Regev4

1 Ben-Gurion University of the Negev; ilse Katz Institute for Nanoscale Science & Technology

2 Ben-Gurion University of the Negev; Ilse Katz Institute for Meso and Nanoscale Science and Technology, Ben-Gurion University
3 Ben-Gurion University of the Negev; Ben-Gurion University of the Negev
4 Department of Chemical Engineering, Ben-Gurion University of the Negev; Ilse Katz Institute for Meso and Nanoscale Science and Technology, Ben-Gurion University

The Critical Role of Nanotube Shape in Cement Composites
Roey Nadiva*, Michael Shteina,b, Maor Refaelic, Alva Peledc and Oren Regeva,b
aDepartment of Chemical Engineering, bIlse Katz Institute for Nanoscale Science and Technology, cDepartment of Structural Engineering, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel.
* E-mail address: roeynadiv@gmail.com (Roey Nadiv).
Abstract
The growing availability of nanotubes and the increased knowledge about their loading in polymers have prompted the incorporation of nanotubes in cementitious matrices. We explored the effects of loading straight tungsten di-sulfide nanotubes (WS¬2¬NT) or waved carbon nanotubes (CNT) in cementitious matrices and found that their inclusion in these composites at exceptionally low concentrations (0.063 vol% and 0.15 vol% for WS2NT and CNT, respectively) enhanced the composite’s mechanical properties, including compressive and flexural strengths (25-38%) and toughness (67-90%). Thermal analysis and electron microscopy indicated that nanotube incorporation in cementitious matrices also accelerated hydration reaction kinetics. We showed that the straight WS2NTs bridged pores and cracks more effectively than the waved CNTs, which resist crack propagation via an anchoring mechanism. A comparison to representative cement nanocomposite systems shows that nanotubes, offer better reinforcement efficiencies than particulate nanomaterials, yielding high mechanical properties enhancement at low concentration.

 

[421] GRAPHENE RIBBONS FROM GRAPHITE: THE EFFECT OF DISPERSANT STRUCTURE

 

Maxim Varenik1, Micah Green2, Oren Regev1

1 Department of Chemical Engineering, Ben-Gurion University of the Negev; Ilse Katz Institute for Meso and Nanoscale Science and Technology, Ben-Gurion University
2 Artie Mcferrin Department of Chemical Engineering; _

Graphene ribbons from graphite: the effect of dispersant structure
Maxim Varenika, Micah J. Greenc* and Oren Regeva,b*
aDepartment of Chemical Engineering, bIlse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
cArtie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843-3122, USA

Dispersants in sonication-assisted exfoliation of graphite into graphene not only stabilize graphene sheets in aqueous solutions, but can also direct fragmentation and template graphene structure. Graphite was exfoliated in the presence of different pyrene derivatives. Dispersions were analyzed using various electron microscopy techniques (cryogenic and room temperature transmission electron microscopy, scanning electron microscopy), Raman, and zeta potential measurements. Stable dispersions prepared using 1-pyrenebutyric acid (PBA) contain graphene ribbons (GR), consisting of individual GR ~0.5 µm in width and several microns in length, while other pyrene derivatives produced graphene flakes. A possible formation mechanism relates to dispersant’s ordered assembly on top of the graphite induced by its two-segment structure, leading to cracking only along certain vectors; these cracks propagate and eventually template the graphene down to GRs and other anisotropic graphene flakes. Additionally, the carboxylic moiety in PBA makes it possible to tune the GR’s zeta potential by changing the pH. Lowering the pH below a critical value causes aggregation, which can be reversed by restoring the original pH value. These ribbons could be applied as fillers in composite materials, foams, and films.

KEYWORDS: Graphene; Pyrene; Dispersant; cryo-TEM; Graphene Ribbon; Graphene Production

 

[425] SELF-ASSEMBLY OF BOTTLEBRUSH BLOCK COPOLYMERS AND GOLD NANOPARTICLES IN THIN FILMS

 

Yaron Aviv1, Roy Shenhar1

1 The Hebrew University of Jerusalem; Givat Ram

Self-assembly of Bottlebrush Block Copolymers and Gold Nanoparticles in Thin Films
Yaron Aviv and Roy Shenhar*
Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel

The research on block copolymer-nanoparticle composites has attracted considerable interest in the last two decades. Block copolymers consisting of two chemically distinct polymers joined together by a covalent bond self-assemble upon annealing into various ordered microstructures (lamellae, cylinders or spheres), with periodicities on the scale of 2-200 nm that are dictated by the volume fractions of each blocks. The periodic nanostructures formed by the self-assembly of BCPs can be used to organize nanoparticles (NPs). The nanoparticle surface can be modified to interact selectively with one block of the copolymer, enabling the creation of periodic NP arrays, where the NPs are segregated in the domains formed by this block.
Bottlebrush block copolymers (BB BCPs) represent a new class of polymers with a unique, three-dimensional and highly tunable molecular architectures, which upon self-assembly form well segregated periodic nanostructures. The aim of this research is to push the limits of BCP/NP assembly by employing BB BCPs in order to achieve nanoparticle arrays with greater order (Figure 1). In this poster, initial results on the assembly of polystyrene-block-polylactide BB BCP with gold NPs will be discussed and compared to the assembly with the corresponding linear block copolymer.

Figure 1. Co-assembly of Au nanoparticles with bottlebrush block copolymers.

 

[426] DETECTING MOLECULES OF BIOLOGICAL INTEREST VIA SOLID-STATE NANOPORES

 

Abeer Karmi1

1 Hebrew University ; Institute of Chemistry, and the Centre for Nano Science and Nanotechnology

Detecting Molecules of Biological Interest via Solid-State Nanopores
Abeer Karmi1, Dvir Rotem1, Liron Nuttman2, Noam Attias2, Oded Shoseyov2 and Danny Porath1*
1. Institute of Chemistry and Center for Nanoscience and Nanotechnology, the Hebrew University of Jerusalem, Israel.
2. Institute of Plant Science and Genetics in Agriculture, Food and Environmental Science, the Hebrew University of Jerusalem, Rehovot, Israel.

In the last twenty years, nanopores have become known for their sensing abilities. They offer sensitivity, selectivity and rapid detection of analytes. Nanopore-based sensors have plenty of uses in medical diagnosis and personalized medicine. Nanopores have proven to be useful in improving and developing the field of DNA sequencing. Low cost and high speed sequencing impacts biomedical research that can aid the development of several new genomic and technological studies.
Solid state nanopores are fabricated by drilling through a thin insulating membrane composed of Si3N4 using HR-TEM. The membrane is then placed between two chambers filled with electrolyte solution. The desired analyte can be driven through the pore by voltage application, and ionic current flowing through the pore is monitored. When an analyte is translocated through the pore, a blockage in the ionic current, which is typical to the analyte, is observed. We modify these nanopores to adjust them for various applications. For instance, we exploring a hybrid pore with an extremely stable ring-shaped protein, SP1 (stable protein 1), which is positioned on top of the pore. We concentrate on slowing down DNA translocation through this hybrid pore in order to sequence DNA

 

[427] SOLAR SYNTHESIS OF PBS-SNS2 SUPERSTRUCTURE NANOPARTICLES

 

Olga Brontvein1

1 Weizmann Institute of Science; Materials and Interfaces

SOLAR SYNTHESIS OF PbS-SnS2 SUPERSTRUCTURE NANOPARTICLES
Olga Brontvein1, Ronit Popovitz-Biro2, Daniel Feuerman3, Reshef Tenne1 and Jeffrey M. Gordon3,4,*
1. Department of Materials and Interfaces, Weizmann Institute of Science, P.O. Box 26, Rehovot, Israel.
2. Electron Microscopy Unit, Weizmann Institute of Science, P.O. Box 26, Rehovot, Israel.
3. Department of Solar Energy and Environmental Physics, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Israel.
4. The Pearlstone Center for Aeronautical Engineering Studies, Department of Mechanical Engineering, Ben-Gurion University of the Negev, Beersheva, Israel.
5.
Inorganic fullerene-like structures and inorganic nanotubes became a world popular research subject in recent years. So far a number of synthetic routes have been developed for production of inorganic nanotubes made of misfit layered compounds.
A new procedure for the synthesis of PbS-SnS2 misfit fullerene-like nanoparticles is represented here1. This is a fundamentally distinct type of misfit nanostructure, closed-caged nanoparticles from PbS-SnS2, which, had neither been proposed nor synthesized previously. The unique reactor conditions created in the solar furnace are found to be particularly conducive to the formation of these nanomaterials. Detailed structural and chemical characterization revealed a spontaneous inside-out formation mechanism, with a broad range of nonhollow fullerene-like structures starting at a diameter of ∼20 nm and a wall thickness of ∼5 layers.

Figure 1: High-resolution STEM HAADF image of a single PbS-SnS2 superstructure.
1. O. Brontvein, A. Albu-Yaron, M. Levy, D. Feuerman, R. Popovitz-Biro, R. Tenne, A. Enyashin and J. M. Gordon, ACS Nano, 2015, 9, 7831-7839.

 

[428] POLYMER NANOCOMPOSITE :IMPROVING GAS BARRIER AND MECHANICAL PROPERTIES

 

Sivan Peretz Damari1, Oren Regev2

1 Chemical Eng.; Ben Gurion University
2 Department of Chemical Engineering, Ben-Gurion University of the Negev; Ilse Katz Institute for Meso and Nanoscale Science and Technology, Ben-Gurion University

Polymer nanocomposite :Improving Gas barrier and mechanical properties
Sivan Peretz Damari1 and Oren Regev 1, 2
1Department of Chemical Engineering and 2Ilse Katz Institute for Meso and Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel

Abstract
Polymer based nanocomposites (PNC) have become a prominent area of current research and development. This material exhibits substantial property enhancement at much lower loading than polymer composite with conventional micro scale fillers (such as glass or carbon fiber). Reduction in polymer permeability is both fundamentally important and a practical necessity in the polymer industry. The barrier properties of polymers can be significantly altered by inclusion of impermeable lamellar fillers with sufficient aspect ratio to alter the diffusion path of gas-penetrant molecules. One of the most common barrier materials is clay (such as montmorilonite) , however, it is less effective as water vapor barrier since it absorb water and swells. Therefore, we suggest using graphene nanoplatelets as barrier fillers. The tremendous interest in graphene lies in its one-atom-thick nature, with a densely packed conjugated structure that is capable of exhibiting unprecedented electrical, thermal, and mechanical properties. In addition high aspect ratio (l/d > 1000) graphene are known to be impermeable to most gases and liquids, much like clay, making them of great interest for the preparation of barrier nanocomposites.
In this study we investigate the effect of graphene sheets with various aspect ratio on the barrier and mechanical property of polyurethane. We have demonstrated ~40% reduction for water vapor permeability and also achieved ~70% fracture toughness enhancement.

 

[434] IN SITU HIGH PRESSURE RAMAN AND FLUORESCENCE INVESTIGATION ON MONOLAYER WS2

 

Qiang Zhou1

1 College of Physics; State Key Lab of Superhard Materials

In situ high pressure Raman and fluorescence investigation on monolayer WS2
Bo Han, Fangfei Li, Yuanbo Gong, Xiaoli Huang, Hanxue Gao, Qiang Zhou*
College of Physics, State Key laboratory of Superhard Materials, Jilin University P.R. China.

It is beyond the question that transition metal dichalcogenides (TMD) such as tungsten disulfide are in possession of several qualities in photonic, mechanical and particularly electronic fields. Differentiating from its bulk counterparts that are in-direct semiconductor, the monolayer of WS2 has a direct band gap around 1.94eV and thus a prominent photoluminescence. The mechanism of these qualities due to structural changes is crucial for future application.
In this study, WS2 monolayers are well synthesized by a traditional CVD methodology. We exert quasi-hydrostatic pressure on WS2 monolayer ticking up to 20GPa by a diamond anvil cell(DAC). Lattice dynamic properties are examined by Raman Scattering which shows significant blue-shift in proceeding and a premier in-plane E2g mode splitting at 2.18GPa, indicating a structural deformation of the lattice. Further implied from the PL spectrum, the rich band structure undergoes an apparent blue-shift from 640nm to 620nm, suggesting an enlargement of the band gap. Our study allows for investigation of few layered WS2, other 2dimension TMD and further device application of this kind of materials.

Acknowledgment
The authors graciously acknowledge the National Natural Science Foundation of China for funding (grant nos. 11274137, 51032001, 11074090, 51025206, 11204100 and 11474127), National Basic Research Program of China (no. 2011CB808200), Program for Changjiang Scholars and Innovative Research Team in University (no. IRT1132), and National Fund for Fostering Talents of Basic Science (no.J1103202).

Corresponding author Email: zhouqiang@jlu.edu.cn

 

 

 

 

[437] MAGIC SIZE III-V SEMICONDUCTOR CLUSTERS: SYNTHESIS AND PROPERTIES

 

Jiajia Niing1, Uri Banin2

1 The Hebrew University of Jerusalem; Institute of Chemistry
2 Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University, Jerusalem ; The Hebrew University of Jerusalem

Magic Size III-V Semiconductor Clusters: Synthesis and Properties
Jiajia Ning, Uri Banin
Institute of Chemistry and the Center for Nanoscience and Nanotechnology,
The Hebrew University of Jerusalem, Jerusalem 91904, Israel
Magic size semiconductor clusters represent a molecular limit for semiconductor nanocrystals. Such clusters, previously mostly studied for II-VI and IV-VI semiconductors, are characterized by well defined size with particular stability often assigned to their closed-shell architecture. is formed only by clusters containing a well-defined number of atoms. Here we synthesized magic size nanoclusters of III-V semiconductors which have been rarely studied, including both magic sized InP nanocrystals (MInP NCs), and InAs clusters. The systems were characterized by absorption, Xray diffraction, and their thermal stability in the synthesis.
Furthermore due to large surface to volume ratio inherent to the clusters, the emission of MInP NCs is very weak. To address this, we also developed and studied the growth of protective high band gap ZnS shell onto the MInP NCs via layer-by-layer method. The properties of such coated MInP NCs were characterized. Transition between different emission properties was observed using both spectral measurements and fluorescence lifetimes. Several mechanisms for the observed emission behavior and the transition will be discussed.

Keywords: magic size nanoclusters, emission, InP nanocrystals, core/shell, dopant

 

[439] COPPER SULFIDE NANOCRYSTALS LEVEL STRUCTURE AND ELECTROCHEMICAL FUNCTIONALITY TOWARDS SENSING APPLICATIONS

 

Kathy Vinokurov 1

1 The Hebrew University of Jerusalem; The Hebrew University of Jerusalem

Copper sulfide nanocrystals level structure and electrochemical functionality towards sensing applications

Kathy Vinokurov,1 Orian Elimelech,1 Oded Millo2 and Uri Banin1

1Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
2Racah Institute of Physics and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel

The level structure of 7 and 14 nm in diameter copper sulfide nanocrystals were investigated by correlating scanning tunneling spectroscopy and cyclic voltammetry data in relation to sensing applications. Upon oxidation of Cu2S nanocrystals in the low-chalcocite phase, correlated changes are detected by both methods. The cyclic voltammetry oxidation peak of Cu(1+) down shifts, while in-gap states, adjacent to the valence-band edge, appeared in the tunneling spectra. These changes are attributed to Cu vacancy formation leading to a Cu depleted phase of the nanocrystals.
The relevance of the oxidation to the use of copper sulfide nanocrystals in hydrogen peroxide electrochemical sensors was also studied. A significant decrease in the electrochemical sensitivity for the oxidized copper-deficient Cu2-xS phase was observed. This effect should be taken into consideration when considering use of copper sulfide nanocrystals towards bio-compatible electro-sensing systems.

 

[440] ELECTRONIC PROPERTIES OF NANOCRYSTALLINE Π-SNS AND Π-SNSE – A NEW CUBIC PHASE OF TIN SULFIDE AND TIN SELENIDE

 

Elad Segev1

1 Ben-Gurion University of the Negev; Ilse Katz Institute for Nanoscale Science and Technology

Electronic Properties of Nanocrystalline π-SnS and π-SnSe – a new cubic phase of Tin Sulfide and Tin Selenide

Elad Segev‡, Ran E. Abutbul†‡, Yuval Golan†‡ and Guy Makov†‡
†Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
‡Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
We report on structural, energetic and electronic properties of a new phase in the binary SnX (X=S,Se) systems. The structure and atomic positions of the -SnS,Se phase consisting of 64 atoms per unit cell were relaxed using DFT-PBE calculations and showed a stable structure which is analogous to the recently reported cubic phase of SnS (a0 = 11.595Å, No. 198) and may be considered as a distorted rocksalt phase. The thermodynamic stability was considered in comparison with the bulk stable orthorhombic phase (also considered a distorted rocksalt phase) with 8 atoms per unit cell and the ideal rock salt phase. Band structure calculations indicate that the new phases have larger bandgaps than the ideal rocksalt phase indicating a possible stabilisation mechanism. The value obtained for the bandgaps are in good agreement, possibly fortuitous, with the measured bandgaps.

 

[445] ZINC CHALCOGENIDE SEMICONDUCTOR NANOCRYSTALS

 

Alisa Hagen1

1 Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel; Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel

Alisa Hagen1,2, Guohua Jia1,2, Inna Popov2 and Uri Banin1,2
1Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
2Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
The bottom-up approach for the synthesis of semiconductor nanocrystals provides size and shape controlled particles with tunable properties for numerous applications. While the syntheses of cadmium chalcogenide nanocrystals are well developed in the literature, there is still a lack of reports involving zinc chalcogenide systems of different morphologies and structures.
The development of nanocrystals containing zinc is highly important for a variety of applications in which cadmium free structures are advantageous; for instance, zinc chalcogenide nanocrystals could be used as sensors in biological imaging. Here, we report a general strategy for synthesizing quasi one-dimensional (1D) nanorods and unique structure of nanorod couples of ZnSe via a colloidal chemical synthetic approach. Wurtzite ZnSe nanorod couples connected by twinning structures are synthesized by means of a self-limited assembly process, whereas 1D nanorods are synthesized by a ripening process starting from ultrathin nanowires through thermodynamically driven material diffusion. The effects of different synthesis parameters will be presented and will be supported by different characterization methods, such as transmission electron microscopy, spectroscopic measurements, XRD, etc.
We are now working on synthesizing more particular rod and rod couple structures such as semiconductor-metal hybrid nanorod systems in order to enable the design of high quality nanocrystals which in the future could be used for photocatalysis and in optoelectronic applications.

References:
G. Jia, A. Sitt, G.B. Hitin, I. Hadar, Y. Bekenstein, Y. Amit, I. Popov and U. Banin “Couples of colloidal semiconductor nanorods formed by self-limited assembly“, Nature Materials 13, 301–307 (2014)
G. Jia, U. Banin “A General Strategy for Synthesizing Colloidal Semiconductor Zinc Chalcogenide Quantum Rods“, J. Am. Chem. Soc., 2014, 136 (31), pp 11121–11127

 

[446] HEAVILY DOPED SEMICONDUCTOR COLLOIDAL NANOCRYSTALS – IMPURITY DOPING AND ITS IMPLICATIONS ON THE RESULTING STRUCTURE

 

Yorai Amit1

1 Institute of Chemistry, Hebrew University, Jerusalem 91904,Israel. ; Huji

Heavily Doped Semiconductor Colloidal Nanocrystals – impurity doping and its implications on the resulting structure
Yorai Amit1,2, Yuanyuan Li2, Anatoly I. Frenkel*,2, and Uri Banin*,1

1 The Institute of Chemistry and The Center for Nanoscience and Nanotechnology, Hebrew University, Jerusalem 91904, Israel.
2 The Department of Physics, Yeshiva University, New York, New York 10016, United States
Tuning of the electronic properties of pre-synthesized colloidal semiconductor nanocrystals (NCs) by doping plays a key role in the prospect of implementing them in advanced transistors, photodiodes and photodetectors. While routes for impurity doping of semiconductor NCs have already been introduced, the understanding of the doping process, the nature of interaction between the impurity and host atoms, and the conditions affecting the solubility limit of impurities are still unclear. Here, we used a post-synthesis diffusion-based doping reaction to introduce different impurity atoms, at various concentrations, into InAs NCs. X-ray absorption fine-structure (XAFS) spectroscopy was employed to determine the location of the impurity, enabling a systematic study of the impurity concentration dependence as a function of the size of the host NC on the identified impurity site to derive a self-consistent picture of the resulting structure While Cu doping previously revealed purely interstitial doping for a very wide range of impurity/NC ratios, doping with Ag impurities was found to be a heterogeneous system where the impurities initially dope the NC, through a substitutional mechanism, until the “solubility limit” is reached after which the rapid growth and formation of metallic structures is identified. These findings establish the reproducibility as well as the subtlety of the diffusion-based doping strategy. The understanding of the doping mechanism and insights on the impurity solubility limit are of grave importance when attempting to implement such heavily doped semiconductor NCs in various optoeldctronic devices.

 

[477]   PbSe/PbS alloyed quantum dots

 

Arthur Shapiro and Efrat Lifshitz*

Schulich Faculty of Chemistry, Russell Berrie Nanotechnology Institute, Solid State Institute, Technion-Israel Institute of Technology, Haifa 3200013, Israel (*ssefrat@technion.ac.il)

 

Lead chalcogenide (group IV-VI semiconductors) colloidal quantum dots (CQDs) have raised scientific and technological interest due to their optical tunability in the infrared (IR) spectral regime (0.7-3.5µm).This wide tunability range is a result of a narrow band gap and a large exciton Bohr radius (e.g. ab(PbS)= 18 nm, and ab(PbSe)= 46 nm). Moreover, they have relatively small effective masses of both the hole and electron. Therefore, they provide a unique opportunity for fundamental studies of strongly confined quantum systems.

However, the different lattice constants of both materials, PbSe and PbS causes to a big strain in the interface, leading to a low values of quantum yield, etc.

In this work we show how to achieve high quality PbSe/PbS CQDs, with sharp size distribution and characterize them by using spectroscopical, structural and compositional characterization methods. Moreover, an evidence for the alloy is given  by different means.

 

[453] FACETING IN MULTI-WALLED NANOTUBES

 

itai leven1

1 Tel Aviv University; Tel Aviv University

Faceting in layered nanotubes
I. Leven1,2*, R. Guerra3,*, A. Vanossi3, E.Tosatti3, Oded Hod1,2
1 Department of Physical Chemistry, School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
2 The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv, IL 6997801
3 International School for Advanced Studies (SISSA), Via Bonomea 265, 34136 Trieste, Italy;

Abstract:
Nanotubes hold great promise for the miniaturization of advanced technologies. Their exceptional physical properties are intimately related to their detailed morphological and crystal structure. Importantly, circumferential faceting of multi-walled nanotubes serves to reinforce their mechanical strength and alter their tribological and electronic properties. Here, nanotube faceting is fully rationalized in terms of interlayer registry patterns. We find that, regardless of the nanotube identity, faceting requires chiral angle matching between adjacent layers. Above a critical diameter that corresponds well with experimental findings, achiral multi-walled nanotubes display evenly spaced extended axial facets, the number of which is determined by the interlayer difference in circumferential unit cells. Elongated helical facets, most commonly observed in experiment, appear in nanotubes exhibiting a small interlayer chiral angle mismatch. In the case of uncorrelated wall chiralities faceting is suppressed and surface corrugation induced by the Moiré superlattice is obtained in excellent agreement with experiment. It is therefore evident that gaining control over their interlayer registry matching provides a route for the mechanical enforcement as well as tribological and electronic properties tuning of MWNTs.

 

[454] SCALABLE NONMANUFACTURING OF MONODISPERSE QUANTUM DOTS

 

richard robinson1

1 Materials Science Department.; 214 Bard Hall

Richard Robinson
Associate Professor
Cornell University
Ithaca, NY USA
http://robinson.mse.cornell.edu/

Over the last two decades, nanoparticle synthesis has progressed significantly, to the point of creating a multitude of new shapes and compositions, with tight size controls. The emergence of NP-enabled technologies has created a growing demand for scalable NP synthesis methods. Unfortunately, the conventional synthesis procedure (“hot-injection”) is optimized for laboratory scale studies and does not easily scale, limiting the incorporation of nanoparticles into technology. Scaling up the hot-injection presents important, and yet unresolved, challenges. Specifically, the stringent demand for rapid precursor mixing (due to fast reaction kinetics) pose a critical barrier to production as larger reactor volumes, hindering reproducibility and control. We embraced these challenges as an opportunity to investigate new synthesis methods that upend the conventional hot-injection technique.

In this talk I’ll discuss our work on new methods for nanoparticle scale-up synthesis reactions, with the goal of producing nanoparticles for LED lighting. Our group has developed a rational method for the synthesis of monodisperse metal sulfide nanocrystals in organic solutions by using (NH4)2S as a sulfide precursor. The method enables low temperature (< 100 oC) syntheses, open-air reactions, high conversion yields (>90%), and large-scale production of monodisperse nanocrystals can be synthesized in a single reaction (more than 100x that of the conventional “hot-injection” method).
I will also discuss our scalable results using high viscosity in a “heat-up” synthesis. These new highly-viscous regimes alter the kinetics of the reaction and diverge from the classical Le Mer model on solution-phase synthesis. Specifically, we synthesize high-quality metal sulfide NPs (< 7% relative standard deviation for Cu2-xS, CdS, and PbS), and demonstrate up to a 1000 fold increase in Cu2-xS NP production (>200 g) relative to the current field of large-scale (0.1-5 g yields) and lab-scale (<0.1 g) efforts. We provide an explanation of our results by probing the interplay between chemical, thermal, and rheological properties on NP growth and dissolution.

 

[457] POLVINYL ALCOHOL HYDROGELS REINFORCED WITH RESILIN-CELLULOSE BINDING DOMAIN-CELLULOSE NANOCRYSTALS

 

Tiffany Abitbol1, Amit Rivkin2, Tal Ben-Shalom1, Oded Shoseyov1

1 The Hebrew University of Jerusalem; Robert H. Smith Faculty of Agriculture, Food and the Environment
2 The Hebrew University of Jerusalem ; Robert H. Smith Faculty of Agriculture, Food and the Environment

Cellulose nanocrystals (CNCs) and resilin possess distinct yet complimentary properties that

can be harnessed to prepare new, functional materials. CNCs are rod-shaped, highly

crystalline nanoparticles that represent the main structural, load-bearing component in

trees, whereas resilin is a rubbery material found in the organs of anthropods,

whose function require both elasticity and resilience, for example in the femur of fleas.

Recombinant resilin (res) from Drosophila Melanogaster has been genetically engineered to include a

cellulose binding domain (CBD), which provides a conduit to link resilin to CNCs, with binding

efficiencies of up to 20% of the total CNC mass. Here, we present results of hydrogels

prepared from res-CBD-CNCs and polyvinyl alcohol by freeze-thaw cycling, specifically swelling behavior,

crystallinity, mechanical properties, and morphology, with the end goal of the work to produce novel

materials for biomedical applications.

 

[462] UNWRAPPING CORE–SHELL NANOWIRES INTO NANORIBBON-BASED SUPERSTRUCTURES

 

Guy Davidi1

1 Tel Aviv University; Tel Aviv University

Over the last decade one-dimensional nanostructures have attracted considerable attention as promising building blocks for nanoscale devices, owing to their novel physical and chemical properties. In particular, nanoribbons (NRs) are of major interest due to their shape, comprised of a rectangular cross-section on a nanometer scale that can provide unique properties for optical, mechanical and electrical devices. Several experiments on III-V and oxide semiconductor nanoribbons have already shown promising properties, such as the wave-guiding of photons, lasing action, nonlinear polarization and high mechanical flexibility. Although these approaches have been proven to be effective, the controlled synthesis of semiconductor nanoribbons still remains a challenge.
Herein, we demonstrate a simple, and yet robust, method for the fabrication of high quality single-crystal silicon nanoribbons by the unwrapping of core/shell nanostructures. The method is based on the controlled unfurling of germanium core/silicon shell nanowires by an anisotropic plasma step, followed by etching of the sacrificial germanium core, under wet or dry conditions. Our method allows tight control over the physical and chemical properties of the fabricated nanoribbons, such as lateral and horizontal dimensions, dopant concentration control along all directions, formation of multi-layered ribbons, orthogonal chemical modification of ribbon faces etc. Lastly, the method is not only limited to the fabrication of silicon nanoribbons, but can also be easily applied to a wide range of semiconductor and dielectric materials.

 

[466] RAMAN SCATTERING FROM SINGLE WS2 NANOTUBES EMBEDDED WITHIN STRETCHED PVDF SUBMICRON FIBERS

 

Olga Grinberg1, Alla Zak1

1 Holon Institute of Science; Holon Institute of Science

Raman scattering from single WS2 nanotubes embedded within stretched PVDF submicron fibers

Olga Grinberg1, Ron Avrahami2, Eyal Zussman2, Tsachi Livneh3, Alla Zak1
1Holon Institute of Technology, 52 Golomb St., P.O.Box 305, Holon, Israel
2Department of Mechanical Engineering, Technion – Israel Institute of Technology, Technion City – Haifa 32000, Israel
3Department of Physics, Nuclear Research Center, Negev, P.O. Box 9001, Beer-Sheva, 84190, Israel

Multiwall inorganic WS2 nanotubes (INT-WS2) possess high mechanical strength, high flexibility, and interesting surface chemistry. Significant improvement of crystallization, mechanical and tribological behavior of various polymers can be achieved by the formation of nanocomposites upon the embedment of INT within their structures. The long PVDF (polyvinylidene difluoride) – WS2 composite fibers used in this study, were obtained by electrospinning, and featured the diameter in the range of 0.5–1.5 µm. The majority of the embedded WS2 INTs have the length of 5 – 10 µm and diameter of 50 – 120 nm.
The objective of this work is to investigate what can be learned on the nature of INT-polymer interactions, by exploring the effect of fibers’ stretching on the Raman scattering of single nanotube, embedded within a single PVDF fiber. A computer controlled load-cell set-up, which was build for this study, enables the submicron to mm range stretching of composite fibers with simultaneous measuring of its Raman scattering response under a microscope. For this study a well-equipped Horiba LabRam HR Evolution Raman scattering spectrometer with multiple (785, 633, 532, 325 nm) excitation energy sources was used. We present here the results measured on the five different single fibers, where we detected from 3 cm-1 to 5 cm-1 red shift in the frequencies of two main bands of WS2, one – comprises of the 2LA(M) and E2g vibration modes and second – vibration mode of the A1g symmetry. The shift occurs between the fibers’ “relaxed” and “almost torn” states. The nature of this response is currently under study.

 

[467] SILICON NANOWIRES GROWTH BY CONFINEMENT-GUIDED METHOD

 

Roi Vizel1, Alon Kosloff2, Fernando Patolsky3

1 The Department of Materials Science and Engineering; Center for Nanoscience and Nanotechnology
2 Tel Aviv University; School of Chemistry
3 School of Chemistry; School of Chemistry

Silicon Nanowires Growth by Confinement-Guided Method

In the recent years, semiconducting nanowires have attracted much interest, and were widely explored for developing electronic, optoelectronic, and biosensing devices, due to their unique properties due to the sub-micron dimensions. Great efforts have been taken for developing a simple, effective, manufacturable large-scale assembly method of nanowires growth with controlled and uniform orientation and dimensions, at spatially well-defined locations, while achieving high quality electrical properties. Even though a major progress has been achieved in this field of research, it still remains the bottleneck challenge for integrating these structures into commercial devices.
Here, we present a simple and robust grow-in-place approach, allowing the positioning and orientation of synthesized nanowires to be precisely controlled by a confinement-guided method. This approach enables the bottom-up synthesis of nanowires through the vapor-liquid-solid (VLS) mechanism, without the need of harvesting or assembling steps. Our method also prevents nanowires contamination through growth in the confinement tunnels, resulting in fine and suitable electrical properties for the intended devices. This method advances the ability of integrating nanowires as building blocks for a broad variety applications, and to exploit their full potential.

 

 

 

 

[471] FUNCTIONAL PEPTIDE ASSEMBLIES ON SURFACES: TOWARDS ENVIRONMENTALLY FRIENDLY ANTIFOULING MATERIALS

 

sivan nir1, Tal Zada2, Meital Reches3

1 Institute of Chemistry, the Hebrew University of Jerusalem; The Harvey M. Krueger Family Center for Nanoscience and Nanotechnology
2 The Hebrew University of Jerusalem; The Hebrew University of Jerusalem
3 The Hebrew University of Jerusalem; The Center for Nanoscience and Nanotechnology

Functional Peptide Assemblies on Surfaces:
Towards Environmentally Friendly Antifouling Materials
Sivan Nir, Tal Zada and Meital Reches*
Institute of Chemistry, The Hebrew University of Jerusalem, Israel
The Harvey M. Krueger Family Center for Nanoscience and Nanotechnology

Biofouling is an undesirable process in which a surface becomes encrusted with organisms and their by-products. This unwanted colonization has a serious impact on marine devices, as it lead to deterioration of the surfaces and can alter fluid flow rates leading to significant increase in cost of marine transportation. In the healthcare system, the attachment of bacteria and biofilm formation on medical devices may lead to a severe infection and consequently death. In the US alone, the American Centre for Disease Control and Prevention (CDC) reported that healthcare-associated infections account for an estimated 1.7 million infections and 100,000 deaths annually.
Many approaches to prevent biofouling have been suggested, however, they suffer from drawbacks such as release of toxic materials to the surroundings, low stability that limits their long-term application or complex and expensive synthesis.

We have recently designed a tripeptide that self-assembles into a nano-metric coating that interfere with the attachment of organisms to the substrate and therefore act as an antifouling agent.
The peptide contains three elements that enable i) its self-assembly into a film, ii) its adsorption onto any substrate and iii) its antifouling activity. The peptide-based coating completely prevented the first stage of biofouling and abolished the adsorption of proteins to a substrate. Moreover, the coating significantly reduced the amount of different bacterial strains adsorbed on the substrate.

 

[478] UNDERSTANDING THE ROLE OF CELLULOSE NANOCRYSTAL SURFACE CHARGE ON RHEOLOGY AND CHIRALITY

 

Doron Kam1, Tiffany Abitbol2, Oded Shoseyov3

1 Robert H. Smith Faculty of Agriculture, Food and Environment ; The Hebrew University of Jerusalem
2 The Hebrew University of Jerusalem; Robert H. Smith Faculty of Agriculture, Food and the Environment
3 The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem; The Hebrew University of Jerusalem

Understanding the role of cellulose nanocrystal surface charge on rheology and chirality
Doron Kam, Tiffany Abitbol and Oded Shoseyov
Robert H. Smith Faculty of Agriculture, Food and Environment
The Hebrew University of Jerusalem, Rehovot

Cellulose nanocrystals (CNCs) are rod-shaped crystals that are extracted by the strong acid hydrolysis of cellulose fibers, which preferentially degrades amorphous regions. The hydrolysis conditions and the cellulose source significantly impact the properties of the resulting particles, including particle size, surface charge and self-assembly.
It was noted that minor differences in CNC production, led to large differences among the final properties of the suspensions. To better understand these effects, we studied the properties of four different CNC suspensions in detail. This study concentrated specifically on the interplay between particle size and surface charge, which give rise to differences in the phase behavior and the rheology of the samples.
During acid hydrolysis with sulfuric acid, acidic sulfate half-ester groups are grafted onto the nanoparticle surface, resulting in a negatively charged particle characterized by an electric double layer. This electrical property plays an important role in the interaction between CNCs and the suspension medium, and between CNCs. The combination of electrostatic repulsion and the attractive effects of van der Waals, hydrogen bonding and cellulose-cellulose interactions are described by Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The balance between these interactions determines the dominant force as a function of particle separation.
Considering CNCs, at one extreme, surface charge is zero, attractive forces dominate and aggregation occurs. At the second extreme, electrostatic repulsion dominates leading to a colloidally stable suspension. We propose an intermediate regime, where particles are colloidally stable but attractive interactions exert more pronounced effects. Within this regime, the viscosity and phase behavior of the suspensions is influenced by attractive forces, giving results that are in disaccord with theories describing the electroviscous effect and the phase separation of charged rods.

 

[480] AMORPHOUS PHASE CONTENT IN TITANIA CATALYSTS: QUANTITATIVE MEASUREMENTS AND INFLUENCE ON PHOTOCATALYTIC PROPERTIES

 

Vasily Lebedev1, Daniil Kozlov2, Anton Poluboyarinov1, Irina Kolesnik1, Alexei Garshev3

1 Lomonosov Moscow State University, Department of Materials Science; –
2 Lomonosov Moscow State University; –
3 Lomonosov Moscow State University, Department of Materials Science; Baikov Institute of Metallurgy and Material Science Ras

Amorphous phase content in titania catalysts: quantitative measurements and influence on photocatalytic properties
Lebedev V.A., Kozlov D.A., Poluboyarinov A.S., Kolesnik I.V., Garshev A.V.

Further improvement of the photocatalytic activity (PCA) of titania based catalysts is one of the key research issues in the field of heterogeneous catalysis. Unfortunately, the presence of the “invisible” XRD-amorphous part in the catalysts is often underestimated. This decreases the validity of comparison between different catalysts, because the PCA of the amorphous phase is significantly lower than that of crystalline samples. Therefore, a reliable quantitative method for the amorphous phase analysis is required.
In this study we quantitatively measured the total amorphous phase amount in commercially available P25 Evonik (Degussa) and Hombikat UV100 titania catalysts, as well as in pre-synthesized mesoporous titania by XRD phase analysis of multiple sample/standard mixtures. Furthermore, we could distinguish the water content in the amorphous phase from water adsorbed on the material surface using thermal analysis. Additionally, PCA measurements were performed in liquid in an IceGlass quartz reactor with the use of methyl orange (MO) as a photodegradable agent. A high-pressure Hg bulb (5W) was used for illumination. The pH stabilization was achieved using a phosphate buffer solution (pH 6.7). MO concentration changes were measured every 3-5 sec. in a U-shape flow cell with continuous sampling by a peristaltic pump system. We found the negative correlation between the weight amount of amorphous phase and the PCA of titania catalysts. This result was confirmed by measurements of the annealed samples with the decreased amount of the amorphous phase.
This work was supported by RFBR (grant №15-03-99537 А) and M.V.Lomonosov Moscow State University Program of Development.

 

[490] TEMPERATURE DEPENDENT RAMAN SCATTERING IN CH3NH3PBX3 ΗYBRID PEROVSKITES WITH VARIOUS HALIDE COMBINATIONS

 

Athanassios Kontos1, Ralf Niemann2, Andreas Kaltzoglou1, Petra Cameron2, Polycarpos Falaras1

1 National Center for Scientific Research Demokritos; Institute of Nanoscience and Nanotechnology
2 Department of Chemistry; Department of Chemistry

Temperature dependent Raman scattering in CH3NH3PbX3 Ηybrid Perovskites with various halide combinations
Athanassios G. Kontosa*, Ralf G. Niemanna,b, Andreas Kaltzogloua, Petra J. Cameronb and Polycarpos Falarasa

a Institute of Nanoscience and Nanotechnology, NCSR Demokritos, 15310 Athens, Greece
b Department of Chemistry, University of Bath, Bath BA2 7AY, United Kingdom
* Corresponding author: a.kontos@inn.demokritos.gr

This study presents the vibrational properties of single and mixed MAPbX3 (X = Cl, Br, I) perovskites with off-resonance variable temperature Raman measurements. Comparison of results for all perovskite derivatives evidenced emergence of new low frequency vibrational bands indicative of their phase transformation from cubic at 294 K to the orthorhombic phase at 100 K. MAPbBr3, the intermediate species of our halide series, has been further characterized by variable temperature Raman measurements in the entire 100-294 K range (see Figure 1).

Figure 1. micro-Raman spectra of MAPbBr3 for various temperatures (excitation at 785 nm).
Most Raman modes present normal temperature dependence with blue frequency shifts and linewidth narrowing upon reducing the temperature apart from certain methyl ammonium bands: a) the rocking mode (925 cm-1) which presents a steep reduction in the linewidth followed by a plateau for temperatures below the tetragonal I to II phase transition and b) the torsional mode (320 cm-1) which shows abnormal linewidth broadening near the same critical temperature range. The results are analyzed in terms of disorder and different structural orientation of the MA cations, both effects giving implications on the photovoltaic properties of the hybrid perovskites that are considered among the most efficient absorbers in 3rd generation solar cells.

 

[495] ALL-CARBON-NANOTUBE FLEXIBLE NEUROELECTRODES FOR BRAIN STIMULATION AND MONITORING

 

Lilach Bareket1, Moshe David-Pur1, David Rand1, Yael Hanein1

1 Center for Nanoscience and Nanotechnology; Tel Aviv University

All-carbon-nanotube flexible neuroelectrodes for brain stimulation and monitoring

Extensive investigations over the past 50 years revealed the great potential of electrodes for recording and stimulating neuronal signals in the brain. Both implanted and skin biopotential electrodes transduce ionic currents in the tissue to electrons and holes in the electronic device when recording neural activity and vice versa when stimulating the biological tissue. Despite a rapid recent development, contemporary neuronal electrodes are still typified by relatively low signal to noise ratio, low spatial resolution (leading to poor site specificity) and limited biocompatibility. Clearly, further development is needed to make better electrodes suited for seamless integration between electronic devices and neuronal systems.
Here we present a new flexible neuronal electrode device, based entirely on carbon nanotube (CNT) technology, where both the conducting traces and the stimulating electrodes consist of CNT films embedded in a polymeric support. The use of CNTs bestows the electrodes flexibility and excellent electrochemical properties. As opposed to contemporary flexible neuronal electrodes, the technology presented here is robust and the resulting stimulating electrodes are nearly purely capacitive. Recording and stimulation tests with chick retinas as neuronal model validate the advantageous properties of the electrodes and demonstrate their suitability for high-efficacy neuroprosthetics and neural monitoring.

 

[498] EVIDENCE FOR INCREASED FREE ELECTRONS CONCENTRATION IN CU-DOPED INAS NANOCRYSTALS

 

Adam Faust1, Yorai Amit2, Uri Banin3

1 Institute of Chemistry and the Center for Nanoscience and Nanotechnology ; The Hebrew University of Jerusalem
2 Institute of Chemistry, Hebrew University, Jerusalem 91904,Israel. ; Huji
3 Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University, Jerusalem ; The Hebrew University of Jerusalem

Following the footsteps of bulk-semiconductor doping and aiming to increase the variety of nanocrystals (NCs) and enhance control over their properties, new synthesis approaches for intentionally introducing impurities to semiconductor NC have been recently developed. Doping NCs differs from bulk semiconductor doping as the dopants are confined to the small dimensions of the NCs and interaction between dopants, seen only in heavily doped bulk semiconductor, can be achieved with only a few dopants in each NC, making it scientifically interesting system to study with possible future applications. The ability to dope InAs quantum dots (QDs) post-synthesis with controlled level of Cu and Ag atoms achieving n- and p-type NCs makes them highly interesting system and suitable for systematic study of the doping effects on optical and electronic properties. Raman scattering is used in the study of bulk-semiconductor doping to locate low concentration doping, doping concentration and free carrier concentration.
We present here Raman scattering study of Cu-doped InAs QDs focused on the doping effect on the modes of the QD. We reveal the Cu doping causes a decrease in scattering intensity of the LO mode, relatively to that of the TO mode, as well as reduction in the LO over-tone. Increased Cu doping level is also accompanied by a shifting of the TO and LO energies suggesting the ionic nature of the In-As bond weakens. Experimental results rule out the Cu local vibrational mode and red shift in phonons energies expected from by DFT calculation. This suggest the effects measured are not due to structural changes in the NC, however, we believe our experimental results are strong evidence for increased concentration of free electrons leading to weakening of the electron-phonon coupling and masking of the ionic bond. Raman scattering measurements on different sizes of InAs QDs imply the doping effect is stronger as the size of the QD decreases.

 

[507] THE INFLUENCE OF CONTACT EFFECTS ON THE SPR PEAK POSITION IN METAL/SEMICONDUCTOR NANOCOMPOSITES

 

Daniil Kozlov1, Vasily Lebedev2, Alexander Polyakov3, Alexei Garshev4

1 Lomonosov Moscow State University; –
2 Lomonosov Moscow State University, Department of Materials Science; –
3 Lomonosov Moscow State University; Faculty of Materials Science
4 Lomonosov Moscow State University, Department of Materials Science; Baikov Institute of Metallurgy and Material Science Ras

The influence of contact effects on the SPR peak position in metal/semiconductor nanocomposites
Kozlov D.A., Lebedev V.A., Polyakov A.Yu., Garshev A.V.
Zinc oxide and titania are important photocatalysts for photodegradation of organic wastes under UV-light illumination. There are different approaches to expand their scope of applicability by photosensibilisation, and one of them is the decoration of common catalysts with noble metal nanoparticles. In our work we used three methods of the decoration of initial matrices by silver and gold nanoparticles: the Turkevich method, the reduction by borohydride and the one-step hydrothermal synthesis. These methods result in different contacts between metallic and semiconducting nanoparticles.
Obtained nanocomposites were studied with UV-vis spectroscopy, XRD, SEM, TEM with local EELS and EDX-analysis. The photocatalytical activity was measured by photodegradation reaction of methyl orange. The EEL spectra were collected using high resolution transmission electron microscope (Zeiss Libra 200FE) with monochromator and omega-filter. High energy resolution allows us to measure SPR peak position in visible range. Moreover, it is possible to collect simultaneously plasmonic peaks and zero-loss peak, which allows one to calculate the relative thickness of the sample. Therefore, it is possible to collect low-energy EEL spectra from individual nanoparticles with respect to their thickness.
The obtained composites demonstrate different photocatalytic activities. It may be caused by the different contacts in the composites. In the case of slow reduction, it results in heterogeneous nucleation at the matrix surface. Hence, the formed contact is better. According to the results of UV-Vis and EEL spectroscopy, the contact between metallic and semiconducting nanoparticles results in the shift of the SPR peak position. The data on the photocatalytic activity and absorbance spectra of silver-contained composites demonstrate that the sample with lower photocatalytic activity has better contact because of Ohmic contacts between silver and matrices.
This work was supported by RFBR and M.V.Lomonosov Moscow State University Program of Development.

 

[511] CREATION OF NANO-PATTERNED POLYELECTROLYTE MULTILAYERS

 

Lior Asor1, Roy Shenhar2

1 The Hebrew University of Jerusalem; The Institute of Chemistry
2 The Hebrew University of Jerusalem; Givat Ram

Creation of Nano-patterned polyelectrolyte multilayers
Lior Asor & Roy Shenhar
Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
Nanoscale, periodically patterned surfaces attract a considerable interest due to their wide applicability in a range of fields, such as optics (where a well-defined periodicity is crucial for wavelengths selection) and catalysis (where the nanoscale pattern gives rise to a high surface area). A well-defined, nanoscale pattern usually requires the creation of a distinguishable chemical contrast on the surface. To this day, however, such patterns are achieved mainly by electron-beam lithography, which is a very expensive and time consuming process.
In this work we present a non-lithographic solution for the creation of such patterns, using a combination of two self-assembly approaches: micro-phase separation of block copolymers and layer-by-layer deposition of polyelectrolytes. Block copolymers consist of two chemically distinct polymers joined together by a covalent bond. Upon annealing, these copolymers self-assemble into various ordered microstructures such as lamellae and cylinders, with periodicities on the 10-100 nm scale. Surface patterns displayed by block copolymers in thin films serve as templates for further nanoscale construction. The Layer-by-Layer (LbL) technique, which has become a leading approach for the assembly of polyelectrolyte multilayers using electrostatic interactions, can be used to create patterned multilayer arrays of controllable composition. The poster will discuss a thorough characterization of the assembly of patterned multilayers with a polyelectrolyte system that gives rise to non-linear growth.

 

[519] FABRICATION NANODIAMONDS BY LASER SYNTHESIS AND THEIR APPLICATIONS IN INDUSTRY AND MEDICINE

 

Olga Levinson1, Boris Zousman2

1 Ray Techniques Ltd. ; Nanodiamond Technologies
2 Ray Techniques Ltd.; Nanodiamond Technologies

Ray Techniques Ltd (RT) is the Israeli company established in 2009 and engaged in nanodiamond technologies, – manufacturing diamond nano-powder and suspensions by proprietary method and development of their applications in industry, science and medicine.
The developed technology consists of three levels:
 Nanodiamond fabrication – we mix ash with wax, treat the mixture with laser and obtain pure diamond nanocrystals (patent applications in USA, EU, Korea, Japan & Israel).
 Nanodiamond modification: we solve the problem of nanodiamond aggregation which restricts the growth of Global Market of this unique material; special surface treatment (know-how) enables to obtain stable suspensions without aggregates and sediments.
 Design final products: we exploit unique diamond features: highest hardness and wear resistance, highest thermal conductivity and electrical insulation, unique optical and electronic properties, biocompatibility, radiation and chemical resistance; the product list includes antifriction lubricants, coolants, fine polishes, delivery agent for cancer research, thermal grease and adhesive for electronics and other innovative products.
Presently, nanodiamonds are produced on an industrial scale by non-controlled hazardous detonation technology, which cannot provide constant quality and output. Also the absence of industrial technologies for uniform distribution of nanodiamonds in solvents does not enable their wide use in industry.
RT is looking for partners for commercialization of its technology and products. Industrial manufacturing of nanodiamond additives and implementation of the developed technology of laser nanodiamond synthesis will result in rapid increase in the Global Market of nanodiamond powder and compounds and will enable the solving of most serious problems in electronics, machinery, energy and bio-medicine.

 

[523] NANODIAMOND ADDITIVES FOR 3D PRINTING

 

Olga Levinson1, Boris Zousman2, Michael Farber2

1 Ray Techniques Ltd. ; Nanodiamond Technologies
2 Ray Techniques Ltd.; Nanodiamond Technologies

Here we present the results of investigation intended to check the possibility of use nanodiamonds as reinforcing filler in thermoplastics for 3D-printing. To do that we produced filaments from Acrylonitrile Butadiene Styrene (ABS) and from ABS modified with nanodiamonds (ABS-ND) by extrusion and compared the features of manufacturing process and mechanical properties of produced filaments.
ABS was chosen for this experiment as a common thermoplastic polymer widely used in machinery, electronics, household and medical appliances and construction. At last time ABS has become the main material for rapid prototyping by extrusion-based 3D printers. Currently the wide use of this technology is restricted by the high cost of filaments mainly caused by a low productivity of their manufacturing. Improvement of functional characteristics of ABS and reducing manufacturing costs is an actual issue for material engineering.
It was found that ABS modification with 0.05 wt.% specially functionalized nanodiamonds has resulted in significant decrease in extrusion friction enabling to enhance the productivity of filament manufacturing by minimum 50 %; herewith, rotation force reduced by 24 % which can lead to energy saving and prolonged durability of tools.
Use nanodiamond additive in amount of 0.05 wt.% enhanced tensile strength and load of break of ABS by ≈ 14.5 % while stiffness and elastic modulus increased by 22.5 %; wherein, filament prolongation at break reduced by 94 %.
It is expected, that ABS modification by nanodiamonds performed during ABS pellets manufacturing will result in much higher homogeneity of nanodiamond distribution in polymer and better improvement of mechanical and thermal properties.
The company is looking for partners interested in the development of nanodiamond additive to thermoplastics and implementation of nanodiamond technology in 3D printing. The potential market is huge. If only 1 % of currently produced ABS will be modified with 0.05 wt. % of nanodiamonds, 50 ton nanodiamonds annually is required for this application, amount highly increasing current nanodiamond powder Global Market.

 

[536] EPOXY NANOCOMPOSITES WITH MODIFIED CELLULOSE NANO CRYSTALS AS ADDITIVES

 

Eldho Abraham1, Oded Shoseyov1

1 The Harvey M. Krueger Family Center for Nanoscience and Nanotechnology; The Hebrew University of Jerusalem

Epoxy Nanocomposites with Modified Cellulose Nano Crystals as Additives
Eldho Abraham*and Oded Shoseyov*
*R.H. Smith Institute of Plant Sciences and Genetics and The Harvey M. Krueger Family Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Israel

ABSTRACT:
Epoxy nanocomposites composed of highly esterified cellulose nanocrystals (CNC) were prepared and discussed. CNCs which isolated from paper waste were modified with acetic anhydride by a novel method which resulted in highly esterified CNCs (ACNC). Suspensions of these ACNC crystals in acetone were combined with an epoxy (EPON 828) and the curing agent Epikure 3140 by solution mixing. Film casted nanocomposites were produced by a high temperature curing followed by a subsequent room temperature curing. The ACNC content was systematically varied between 0.01 and 1 wt. %. Electron microscopy studies suggest that the ACNC crystals are evenly dispersed within the epoxy matrix. Dynamic mechanical analysis revealed that the glass transition temperature (Tg) of the materials was not significantly influenced by the incorporation of the ACNC filler. The tensile storage moduli (E′) of the nanocomposites increased modestly between room temperature and 150°C, especially for ACNC concentration less than 1. The mechanical properties of the new materials are promised at low filler concentration (Fig.1) as a result of the formation of a percolating ACNC network in which stress transfer is facilitated by strong interactions between the ACNC crystals.

Keywords: epoxy resin, hydrophobic CNC, nanocomposite, percolating network

Fig.1. Tensile properties of ACNC reinforced epoxy nanocomposites

 

 

Grain growth kinetics in nano-sized Li-MgO·1.21Al2O3 spinel

Lee Shelly, Yuval Mordekovitz and Shmuel Hayun
Department of Materials Engineering and the Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, P.O.Box 653, Beer-Sheva 84105, Israel

Grain growth in MgO·nAl2O3 spinel is strongly affected by its stoichiometric ratio, where for n≥1 spinel it is fairly limited comparing to samples with n <1. In order to overcome this difficulty the use of sintering additives was proposed, where the most common is LiF. Even though the effect of LiF on the sintering behavior of MgAl2O4 has been extensively studied, the effect of lithium on grain growth, remain unclear. In the current study the effect of lithium on the grain growth kinetics of non-stoichiometric, MgO·1.21Al2O3 spinel was investigated. Preliminary results show that the grain growth kinetics in nano-sized Li doped MgO·1.21Al2O3 is strongly dependent not only on the Li amount but also on the grain size. The relations between the grain size, lithium amount and grain growth kinetics in non-stoichiometric magnesium aluminate spinel will be discussed.

Keywords: Grain growth kinetics, MgO·nAl2O3 spinel, lithium.

 

Effect of lithium on thermal stability of nano-sized non-stoichiometric magnesium aluminate spinel

Yuval Mordekovitz and Shmuel Hayun
Department of Materials Engineering and the Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, P.O.Box 653, Beer-Sheva 84105, Israel
Abstract
The use of LiF as a sintering additive for fabrication of transparent polycrystalline magnesium aluminate spinel has been widely discussed in the literature. In the present talk the thermal stability of Li-doped non-stoichiometric nano-sized magnesium aluminate spinel, synthesized using a combustion synthesis method was studied using XRD, FTIR, SEM and high temperature differential scanning calorimetry (DSC). It was found that the Li content within the magnesium aluminate spinel is a function of the crystallite size and stoichiometry. Moreover, the limited homogeneity range between LiAl5O8 and MgO·nAl2O3 spinel (n is the ratio between Al2O3 and MgO) found to increase with the reduction in crystallite size. Structural analysis using FTIR spectroscopy indicated that as-synthesized materials were heavily disordered. The effect of the Li on the surface and interfacial enthalpy are stoichiometry dependent (Figure 1), as well as the coarsening path. These dependencies will be discussed.

 

Measuring the Space Charge Potential in Nano-Sized Magnesium Aluminate Spinel Using Off-Axis Electron Holography

 

Mahdi Halabi1,2, Amit Kohn3 and Shmuel Hayun1,2
1. Department of Materials Engineering, 2. Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, P.O.Box 653, Beer-Sheva 84105, Israel
3. Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel

Solute and point defects segregation to grain boundaries are fundamental phenomena in polycrystalline ionic materials [1,2]. Therefore, it is important to investigate the influence of this segregation adjacent to grain boundaries on the defect chemistry and space charged zone (SCZ) [3]. The classical approach for estimating the space charge potential (SCP) in ionic materials is based on defect concentration and formation energy using Boltzmann distribution [2,3]. These estimates are inaccurate because values of the defects formation energy are usually unknown. Additionally, assumptions used [2, 3] for distribution of charge carriers (defects) in SCZ correspond to semiconductors and not to ionic materials. Thus, more realistic models should be developed, for which experimental measurements of the SCZ are required. Here, the SCP is estimated in model systems of MgO·0.95Al2O3 and MgO·1.07Al2O3 spinel using off-axis electron holography (OAEH) [4]. Consequently, the relations between GB segregation (Fig. 1a), electrostatic potential (Fig. 1b) and heat treatment on the SCP are discussed.

Figure 1- a: Line profiles perpendicular to grain boundaries of cation concentration ratio (Mg to Al) as calculated from EELS measurements. b: Line profiles perpendicular to grain boundaries of the electrostatic potential of SCZ as calculated from OAEH measurements. Note: MgO∙nAl2O3 stoichiometric ratios, n=0.95 (red) and 1.07 (blue) heated at 1200°C by SPS

Reference List
[1] M. Rubat du Merac et al., J Am Ceram Soc. 96 (2013) 3341-3365.
[2] N. Nuns, F. Béclin et al., J Am Ceram Soc. 92 (2009) 870-875.
[3] Y. Chiang et al., J Am Ceram Soc. 73 (1990) 1153-1158.
[4] A. Pantzer et al., Ultramicroscopy 138 (2014) 36-45.

 

 

Metal/Metal Alloy Nanoparticles Catalytic Activity Towards the Reduction of 4-Nitrophenol with Sodium Borohydride

 

Shoval Gilboa1, Kirill Magidey1, Tomer Zidki2

1 Department of Chemical Engineering, Ariel University, Israel
2 Department of Biological Chemistry and Schlesinger Center for Compact Accelerators and Radiation Sources, Ariel University, Israel

 

Keywords: Metal alloys, Nanoparticles, Catalysis

Abstract

Nanoparticles (NPs) and in particular metal NPs are vastly studied owing to their properties in variety of fields such as: medicine, optics, electronics, catalysis, etc. Metal NPs are good catalysts as most of their atoms are low-coordinated surface atoms. These atoms are more active than the bulk atoms.

The catalytic reduction of 4-nitrophenol (4-Nip) is one of the most used reactions to test the catalytic activity of metal NPs in aqueous solution. This is due to these the ease of monitoring this reaction by UV-vis spectroscopy. The decrease in the strong absorption of 4-nitrophenolate ions at 400 nm can be readily monitored by UV-vis spectroscopy along with the rise of the 4-phenylamine peak at 300 nm. This reaction is suitable for testing the metal/metal alloy NPs catalytic activity. Due to its optical properties, the reaction of 4-Nip reduction is used as a prototype for catalysis on many metal NPs.

We are studying the catalytic effect of different metals (Au, Ag and Pt) and metal-alloys NPs on the reduction of 4-Nip by sodium borohydride. In this study we synthesize aqueous metal NPs suspensions by the precursor salts reduction with sodium borohydride. The metal alloys are synthesized similarly using a mixture of salts in the precursor solution.

The reactions are monitored using spectrophotometer following the increase of the 4-Nip signal at 400 nm and the increase of the 4-phenylamine signal at 300 nm.

Primary results indicate that:

  1. The order of the metal NPs activity is: Pt < Ag < Au
  2. The alloys NPs show much better activity than the individual metals towards the reduction of 4-Nip.
  3. No induction time is observed for certain catalyst composition (in contrast to the literature) or the reaction is too fast to observe the induction time.
  4. The best catalyst so far is the Ag-Pt alloy nanoparticle.

 

Plasma Treatment of MWINT-WS2 for Synthesis of Single Wall Nanotubes of WS2

 

Volker Brueser1, Ronit Popovich Biro2, Alla Zak3

1Leibniz-Institute for Plasma Science and Technology, Germany, 2Weizmann Institute of Science, Israel, 3Holon Institute of Technology, Israel,

The synthesis of multiwall inorganic nanotubes of tungsten disulfide (INT-WS2) in pure phase and large amounts was reported in 2009. The growth mechanism of this one-pot two-steps reaction of tungsten oxide with hydrogen and hydrogen sulfide, was carefully investigated.[1] The obtained nanotubes are 80-120 nm in diameter and 10-20 micron in length, exhibiting high degree of crystallinity and needle-like morphology.

Nanostructures formed of monomolecular layer attract increasing attention of the scientific community during the last few decades. Among these materials are carbon fullerenes, like C60, single wall carbon nanotubes (SWCNT), graphene and lately monomolecular layers of inorganic transition metal chalcogenides, named 2D-materials. Here, we reported the synthesis of single- to triple-wall WS2 nanotubes (SWINT-WS2) with a diameter of 3–7 nm and a length of 20–100 nm which were produced by radio frequency plasma treatment of multiwall INT-WS2.[2]

Due to their high elastic energy of folding the WS2 nanotubes become less stable, as the radius of curvature shrinks, rendering their synthesis more difficult. Indeed, theoretical calculations have shown that the energy-per-atom increases with a decreasing number of atoms, diameter and number of layers for the WS2 (MoS2) nanotubes. Therefore, generation of the nanotubes of a small size and single layer requires highly exergonic conditions. The developed process for high-power radio frequency plasma irradiation of multiwall INT-WS2 meets these requirements. Moreover, the elastic strain stored in the bent layers of large multiwall nanotubes plays a crucial role in this process, providing an extra stimulus for the SWINT formation.

Careful investigation of the plasma-reactor parameters enables us to further improve the synthesis of single-to-triple wall nanotubes. The majority of the nanotubes obtained under the improved conditions are single walled nanotubes of WS2. Additional work is required in order to scale-up the production of SWINT-WS2 and to control their aspect ratio.

The large surface area/volume ratio of SWINT-WS2 and their semiconductor nature can yield interesting chemical properties, making them suitable for numerous energy storage devices, catalytic applications, hydrogen storage and optoelectronic applications.

References

[1] A. Zak, L. Sallacan-Ecker, A. Margolin, Y. Feldman, R. Popovitz-Biro, A. Albu-Yaron, M. Genut and R. Tenne, Scaling-Up of the WS2 Nanotubes Synthesis,  Fullerene, Nanotubes,  Carbon Nanostruct. 19, 18-26 (2011).

[2] V. Brüser, R Popovitz-Biro, A Albu-Yaron, T Lorenz, G Seifert, R Tenne, and A Zak. “Single- to Triple-Wall WS2 Nanotubes Obtained by High-Power Plasma Ablation of WS2 Multiwall Nanotubes.” Inorganics 2, no. 2 (2014): 177-90.

 

Characterization of nanometric type II superlattice layers for near- room temperature extended short-wave infrared detection.

 

  1. Uliel1,2, D. Cohen-Elias1, N. Sicron1, Y. Paltiel2, M. Katz1

1 Solid State Physics Department, Applied Physics Division, Soreq NRC, Yavne, Israel
2 Applied Physics Department, Hebrew University, Jerusalem, Israel

Extended Short Wave Infra-Red (E-SWIR, 1.7-2.5-mm) photodetectors are required for several defense and civil industry applications. Existing E-SWIR high responsivity detector technology can be divided into two groups, unmatched InGaAs/InP layers, and MCT layers .        

Unmatched InGaAs/ InP layer devices exhibit low operability in Focal Plane Arrays (FPA) due to the large concentration of defects originating in the lattice mismatch. MCT layer devices are expensive and suffer from very low yield. Therefore, there is a need for high quality near room-temperature E-SWIR detectors.

The work presented here focuses on a nanometric Type- Two Super Lattice (T2SL) structure, based on interleaving nano-layers of InGaAs and GaAsSb, grown by MBE process on an InP substrate. These layers were recently proposed as a candidate for near room temperature E-SWIR detection. The quantum confinement effect within the nano-layers allows for bandgap engineering of a new artificial material.

Material characterization, quantum simulation, and device fabrication is presented.

The described structure is adjusted for ~2.35mm detection. The devices fabricated are PIN photodiodes formed by selective diffusion of Zinc. The results show promising high- quantum efficiency E-SWIR detection, while exhibiting relatively low dark currents.

 

 

Mechanistic Insights into Crystallization of Perylene diimide Based Organic Nanocrystals in Aqueous Media.

 

Yael Tsarfati, Shaked Rosenne, Raja Bhaskar Kanth, Haim Weissman,

and Boris Rybtchinski.

 

Department of Organic Chemistry, Weizmann Institute of Science, Rehovot, Israel

 

Supramolecular synthesis allows us a facile fabrication of a wide variety of complex systems from simple molecular precursors. However, understanding of the mechanism of formation, specifically, the transition from solution based molecular recognition into practical solid state nanocrystals has been found to be extremely challenging. Many studies are attempting to achieve insights into the crystallization mechanism, including our own lab.1, 2

 

In this contribution, we present our developing perspective and methodology to target the study of early stage crystallization in organic crystals encapsulating one or two component systems. Our molecular crystals are based on representative simple aromatic compounds – Perylene diimide (PDI) derivatives. These PDI-based electron donors and acceptors are extensively studied in the context of molecular self-assemblies due to their excellent optical and electronic properties that also render them applicable in the fields of solar cells and nano-electronics. Such molecules often assemble into needles-like nanocrystals, depending on their solubility in water and their functional groups. The crystallization evolution is monitored using electron microscopy, including cryo-TEM, and optical spectroscopy to gather experimental data on the intermediate stages and products of crystallization. The results reveal interesting insights both into crystallization in general and into PDI-based co-crystals in particular. We hope that our study will shed light on nucleation and growth mechanisms and increase our control on the processes and products of crystallization. 

 

References

 

(1)      Vekilov, P. G. Nucleation. Cryst. Growth Des. 2010, 10, 5007–5019.

(2)      De Yoreo, J. J.; Gilbert, P. U. P. a.; Sommerdijk, N. a. J. M.; Penn, R. L.; Whitelam, S.; Joester, D.; Zhang, H.; Rimer, J. D.; Navrotsky, A.; Banfield, J. F.; Wallace,  a. F.; Michel, F. M.; Meldrum, F. C.; Colfen, H.; Dove, P. M. Crystallization by particle attachment in synthetic, biogenic, and geologic environments. Science. 2015, 349, aaa6760–aaa6760.

 

 

GaInAs and InGaAsP Based Photovoltaic Absorber Materials for
Optical Power Transmission in the 980 and 1310 nm Range

 

Henning Helmers#, David Lackner, Paul Beutel, Jens Ohlmann, Simon P. Philipps, Frank Dimroth,
Andreas W. Bett

Fraunhofer Institute for Solar Energy Systems ISE, Freiburg, Germany

 

Key Words: III-V, nano materials, power-by-light, semiconductors

Optical power transmission is an emerging technology and enables various remote applications where conventional power supply over copper wire is challenging or even impossible. To power remote electronics by light, three main components are required: a light source (laser), an optical connection (optical fiber or free space transmission), and an opto-electronic converter (photovoltaic cell). Advantages of power-by-light technology include inherent galvanic isolation, electromagnetic compatibility, and the possibility for wireless power transmission.

III-V compound semiconductors (Figure 1) are used to realize high-efficient photovoltaic laser power converters. For optimal system efficiency, the absorber bandgap has to be tuned to match the laser wavelength. This way, thermalization losses (as a major loss mechanism in solar cells) practically vanish. In this work, we report on progress on GaInAs and InGaAsP absorber materials, optimized for wavelengths around 980 nm and 1310 nm, respectively. The materials are grown epitaxially by MOVPE. The Ga0.85In0.15As material system is grown metamorphically on a GaAs substrate, the InGaAsP material system is deposited lattice-matched on an InP substrate.

 

Figure 1: Plot of bandgap and corresponding wavelength of III-V materials over the lattice constant of the respective compound semiconductors.

 

 

 

New Horizons in Structural and Chemical Nanocharacterization of Carbon Based Nanotubes and Graphene

 

Hybrid microscopic technologies have great potential for developing new directions of combined structural and chemical nanocharacterization.  In order for the full utilization of such tools there has to be a unique architecture.  In the case of Raman spectroscopic chemical characterization combined with atomic force microscopy (AFM) both the instrument and the probe design have to be transparently integrated for fully accessing the application potential of this combined tool. In this paper three singular developments will be highlighted.  The first is an AFM instrument that is completely compatible with any optical microscope.  The second is a AFM probe that is transparent and totally non-interfering with the Raman measurement and the third is a measurement of force that has extreme sensitivity down to 1.6pN.  This is in the realm of such techniques as optical tweezers and allows for the sensitivity of optical tweezers without a liquid environment. The applications of such an instrument to the interesting problem of functional imaging in new carbon based materials will be discussed within the context of single walled carbon nanotubes and 2D materials including graphene.  The force sensitivity of the instrument will be described and the ability of the combined tool to functionally follow with AFM based techniques both structural and functional changes will be presented.

 

 

 
 

Summary

 

Title

New Horizons in Structural and Chemical Nanocharacterization of Carbon Based Nanotubes and Graphene

Category

Nanomaterials

Presentation type

Poster Presentation

Submitter

Dr. John Parthenios, FORTH/ ICE-HT, Patras, Greece

 

Speaker

Dr. John Parthenios, FORTH/ ICE-HT, Patras, Greece

 

Main author

Dr. John Parthenios, FORTH/ ICE-HT, Patras, Greece

Authors

Dr. John Parthenios1

 

Prof. Aaron Lewis 2

 

1 FORTH/ ICE-HT, Patras, Greece

 2 Hebrew University of Jerusalem; Applied Physics, Jerusalem, Israel & Nanonics Imaging Ltd., Jerusalem, Israel

 

 

Exhibition Floorplan

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CONTACT DETAILS

KENES EXHIBITIONS 

6 Ha-Yotsrim Str., 3rd floor, Or Yehuda 6021820, Israel
Tel: +972 (0) 74 745 7491  
Email: nanoinni@kenes-exhibitions.com
Website: http://www.kenes-exhibitions.com/

 

PROJECT MANAGER 

Ms. Lyne An
Tel: +972 (0) 74 745 7489
Mobile: +972 54 678 7898
E-mail: lan@kenes-exhibitions.com

 

SCIENTIFIC PROGRAM MANAGER

Ms. Chantal Gelderbloem
Tel: +972 (0) 74 745 7435
E-mail: cgelderbloem@kenes-exhibitions.com

 

REGISTRATION AND ACCOMMODATION MANAGER 

Mrs. Anna Farfanyuk
Tel: +972 (0) 74 745 7487
E-mail: afarfanyuk@kenes-exhibitions.com

 

Contact us

KENES EXHIBITIONS                                                                                                           
3 Ariel Sharon Ave., Or Yehuda 6037606, Israel
Tel: +972 (0) 74 745 7489 
E-mail: biomed@kenes-exhibitions.com
Website: http://www.kenes-exhibitions.com/

 

PROJECT MANAGER                                                     
Ms. Lyne An
Tel: +972 (0) 74 745 7489
Mobile: +972 54 678 7898
E-mail: lan@kenes-exhibitions.com

About Tel Aviv and Israel

 

tel-aviv-beach-663x407

 

TEL AVIV – THE CITY THAT NEVER STOPS

 

Tel Aviv, often called ‘the city that never stops’, was the first modern Jewish city built in Israel, and is the country’s economic and cultural center. It also now has the distinction of being named a top tourist site by major tourist publications. 

Tel Aviv is a national center of rich, innovative and popular culture which serves not only the residents of the city, but the entire country. It is also a huge employment and production center and was recently proclaimed one of the ten high-tech capitals of the world

Visible from a distance with its seafront skyscrapers and exclusive hotels, Tel Aviv presents a lively combination of entertainment venues, shopping malls, exotic markets, nonstop active nightlife, gorgeous golden beaches and wonderful restaurants of all kinds.

The special blend of Mediterranean ambience, seaside resort and modern façade is what makes the city so uniquely appealing.

Stretched along the beautiful beach strip of the Mediterranean, Tel-Aviv is Israel’s largest city and biggest commercial center. It is a busy metropolis, which inspires its visitors with a unique energetic atmosphere of excitement and fun.

Visible from a distance with its seafront skyscrapers and exclusive hotels, Tel-Aviv presents a lively combination of entertainment venues, shopping malls, exotic markets, nonstop active nightlife, gorgeous golden beaches and wonderful restaurants of all kinds.

It is also the country’s greatest cultural center, a home for a variety of museums, galleries, theatres and concert halls.

By contrast, the ancient port city of JAFFA is medieval in appearance.

This special blend of Mediterranean ambience, seaside resort and modern facade is what makes the city so uniquely appealing.

 
ABOUT ISRAEL

For more information about Israel and Tel Aviv, visit Israel’s official site: www.aboutisrael.

 

 

 

 

 

Information

This year,  NanoIsrael 2016, the fifth bi-annual conference & exhibition, will be held on 22-23 February, 2016 at the Smolarz Auditorium, Tel Aviv University.

 

How to get there:

 

 

Map of the Campus

 

 

From North Ayalon:

Exit Rokach Boulevard interchange towards Tel Aviv University,

Turn left at the first circle,

Take the first turn right down to Dr. George Wise Street,

The auditorium is located at Gate four.

 

From South Ayalon:

Exit towards the direction of Sderot Rokach Interchange,

Turn left at the traffic light and immediately right in the direction of the University,

Drive to the first circle and turn left,

Turn Right at the first entrance down to Dr. George Wise street.

 

Through Namir:

From the North: Turn left to Boulevard Einstein,

Turn right into Haim Levanon Street,

Turn left into Dr. George Wise Street.

From the South: Turn right to Haim Levanon Street,

Turn right at the second light into Dr. George Wise Street,

The auditorium is located at Gate four.

Pedestrian entrance through gate 4 is adjacent to the north side of the Auditorium.

 

Public Transportation:

אגד, דן, רכבת ישראל, מטרופולין

 

 

 

Download Conference Brochure HERE

 

Exhibition Opening Hours

All participants are invited to view the exhibition. Opening hours are as follows:

Monday,February 22nd

09:00-18:00

Tuesday, February 23rd

09:00-19:00

 

Airport Information

Ben Gurion International Airport is the main international gateway to and from Israel. It is situated approximately 25km (16 miles) south-east of Tel Aviv.
Journey to Tel Aviv is approximately 30 minutes

 

Transportation to Tel Aviv

For information on schedules and fares: Israel Railways website – Schedules and Fares

 

By Train
The train station is located on Level S of the Landside Building. Train tickets can be purchased through automated ticket dispensers on Level G of the terminal.

To leave Ben Gurion Airport by train, from the arrivals section you need to descend from the Greeters’ Hall (located on Level G), to the railway station (located on Level S). 

By Bus
Upon exit from customs, take either the elevator or escalator to the 2nd floor.  Exit the terminal either by gate number 21 or 23.  Cross over the road for Egged bus number 5 which serves as an internal transport line from Ben Gurion International Airport to El Al Junction.  The price today is NIS 5 (USD 1.20).
You need to take line 475.
Buses arrive at Tel Aviv Central Bus Station.

Note: Buses do not run on Saturday (Shabbat) – from half hour before sunset on Friday till one hour after sunset on Saturday.

By Private Taxi
The Taxi Stations and dispatcher’s counter at Terminal 3 are located on Level G of the Multi Level Road.
Cost is NIS 150 (USD 40-42).
It is recommended not to use random taxi services.
Rate 2 (25% extra) will apply in the following cases:
Night journeys between 21:00 and 05:59 hours the next day.
An additional NIS 2.7 will be applicable for each piece of luggage.

 

Climate and Clothing

Weather in Tel Aviv in March is approximately 23°C during the day. Clothing is informal for all occasions. walking shoes are highly recommended.

 

Insurance

The conference secretariat and organizers cannot accept liability for personal accidents or loss of or damage to private property of participants and accompanying persons.  Participants are advised to take out their own personal travel and health insurance for their trip.

 

Safety and Security

Please do not leave bags and suitcases unattended at any time.

 

Smoking Policy

This is a non-smoking event. Kindly use the hotel designated smoking areas only.

 

Accomodation & Travel

Book your hotel reservation now!!! You will find a variety of hotels in order to suit your needs and desires..

 

Please contact Anna Farfanyuk directly via email:  afarfanyuk@kenes-exhibitions.com to obtain the best and lowest accommodation rates for your group requiring 10 or more rooms.

CONTACT FOR QUESTIONS/FURTHER INFORMATION                                                

Should you have any questions or require information with regard to registration and or accommodation please contact us directly:

 

Registration & Accommodation Department
3 Ariel Sharon Ave., Or Yehuda 6037606, Israel
Tel:  +972 (0) 74 745 7487
Fax: +972 (0) 74 745 7487
Email: afarfanyuk@kenes-exhibitions.com

Cancellation Policy’
All changes or cancellations should be made in writing to: afarfanyuk@kenes-exhibitions.com
Please do not contact the hotel directly.
Cancellations/changes received between 45 to 30 days prior to arrival – full refund less USD $35 handling fee.
Cancellations/changes received between 29 to 14 days prior to arrival – 1 night cancellation charge.
Cancellations/changes received less than 13 days prior to arrival – no refund.
In the event of non- arrival the hotel will automatically release the reservation and payment will be non-refundable. 
 

 
 

Sponsorship Opportunities

The conference will serve as a meeting point for local and multinational companies, venture capitalists, private equity investors, corporate and institutional investors, technology transfer experts, licensing executives, business development executives, university, government and corporate research scientists and government representatives.

We hereby, offer you the exciting opportunity to sponsor the event the estimated 2,000 visitors would benefit tremendously from your generosity.

Applications for sponsorship opportunities should be made via email to Lyne An: lan@kenes-exhibitions​.com

 

Sponsorship Opportunities Booklet

 

Registration

 

 

Conference Online Registration:

shutterstock_185558546 submit
REGISTRATION FEES

The rates below apply to payments received prior to the published deadlines. 

Registration will be confirmed only upon full payment. Unpaid registrations will not be valid.

*** By completing and submitting this registration form, you agree that your details may be included in our database for the purpose of one-on-one meetings.

 

Non-Israeli Participants
 

 

Early Registration
(Extended to November 20,2015 )

 

Late Fee / On Site Registration
(from November 21,2015)

Full Participant US$ 334 US$ 375
Daily Participant (per day) US$ 190 US$ 210

 

 
Israeli Participants
 

 

Early Registration
(Extended to November 20,2015 )

 

Late Fee / On Site Registration
(from November 21,2015)

Full Participant NIS 1240 NIS  1380
Daily Participant (per day) NIS  710 NIS 770
Academic Full Participant *
(University Institute Member)
NIS  1100 NIS 1240
Academic Daily Participant *
(University Institute Member)
NIS  650  NIS 700
Student Full Participant **
NIS 600 NIS 750
Student Daily Participant **
NIS 360 NIS 390
 

 

 

Please note: All prices for Israeli’s include VAT (currently 17%).In case of change in VAT the registration fee will be updated accordingly.

 

* Proof of status is required (valid student / university / institute member card) and must be brought to the registration desk.

 

**Student Rate is applicable until age 30.
The  local Nano centers are subsidizing the registration fee for their students. Please check with your center directly to see if you are eligible.

Outstanding payments will be collected on-site and charged the on-site rate.

 

Registration fees for participants include:

 

METHODS OF REGISTRATION  

 

Please register online or contact: 
Anna Farfanyuk 
Tel: +972 7 4745 7487 
​email: afarfanyuk@kenes-exhibitions.com

 

 

METHODS OF PAYMENT 

 

Credit Card
We Accept: Visa, MasterCard, American Express, Isracard

 

Bank Transfer
IMPORTANT: Please ensure the name of the conference and participant/s are clearly stated on the bank transfer.
Please make drafts payable to: Kenes Exhibitions (Nano Israel 2016), Bank Leumi Le Israel,

Details of Bank Transfer:

Bank  Leumi 10

Branch 837

Account number 22710062

IBAN: IL930108370000022710062,  SWIFT CODE: LUMIILITXXX

 

 

 

REGISTRATION CANCELLATION POLICY 

 

All cancellations must be emailed to : afarfanyuk@kenes-exhibitions.com

Refund of registration fees will be as follows:
Until and including December 20, 2015 full refund less $35 USD for bank charges
Until and including January  20, 2016 50% refund
No refund on cancellations from January 21, 2016

 

 

CONTACT FOR QUESTIONS/FURTHER INFORMATION

 

Should you have any questions or require further information with regard to registration and or accommodation please contact us directly:

Registration & Accommodation Department
3 Ariel Sharon Ave., Or Yehuda 6037606, Israel
Tel:  +972 (0) 74 745 7487
Fax: +972 (0) 74 745 7487
Email: afarfanyuk@kenes-exhibitions.com

An Event By

 

 

 

KENES EXHIBITIONS 

3 Ariel Sharon Ave., Or Yehuda 6037606, Israel
Tel: +972 (0) 74 745 7489  
Email: nanoinni@kenes-exhibitions.com
Website: http://www.kenes-exhibitions.com/

 

PR Services

Welcome to NanoIsrael’s web press room – a comprehensive, constantly updated source of news and information.

Focal point for press releases and PR articles explaining NanoIsrael’s purposes and scope.

Latest information on exhibitors and their innovative products and ideas to be presented at NanoIsrael 2016.

For all use media kits at onsite press room, to be deployed at NanoIsrael 2016 for providing the exhibitors with easily accessible and efficient press coverage services.

For details and further information, please contact:

DMC – Donitza PR
Neve Tsedek St.
Tel Aviv 65146, Israel.
Tel: +972-3-5167336 (Nahum Donitza)
Fax: +972-3-5167338
Email
:
donitza@donitza.co.il 
Website:
www.donitza.co.il  

 

Networking


The partnering event is aimed at supporting the NanoIsrael2016 participants in creating fruitful connections and providing a convenient platform for networking. The event is organized by the Israel-Europe R&D Directorate (ISERD) in co-operation with Enterprise Europe Network (EEN).

 

To utilize this service you need to register your academic / company profile ASAP  – then you’d be able to request meetings with other companies and researchers, and vice versa – all ahead of time. The system will set up the meetings for you automatically. Before the conference you will get your own personal meetings schedule.

 

The service is provided FREE of charge to all NanoIsrael2016 attendees. Please note that you need to have already registered to NanoIsrael2016  in order to enter the meetings.

 

NOTE: You need to register as a new user in this system, even if you already registered to the NanoIsrael2016 conference!

 

 

Networking

 

 

EEN

Enterprise Europe Network (EEN) is happy to offer its services and to assist you with finding suitable partners for your B2B meetings at the upcoming IATI Biomed 2015 event.

EEN is the largest business network in Europe aimed at promoting and facilitating international collaboration. The extensive global EEN network features over 600 partner organizations in more than 50 countries throughout Europe and beyond. The EEN company database holds more than 23,000 companies searching partners for R&D, technology transfer and commercial cooperation.

EEN provides access to partner matching services, referral programs, funding and grants, exclusive events, conferences and more. Join our network today!

For more information and partner finding support, contact Ran Arad at:  ran@iserd.org.il or Sharyn Liberman  :sharyn@iserd.org.il

FAQs

Sponsors

 

Coming Soon..

Exhibitors List

Applied Materials Israel SPONSOR
A.T.S.L- Advanced Technological Solutions     Booth   9
AVBA Hi-Tech Services  Booth 19+20
Bargal Analytical Instruments                   Booth  8
Bar-Ilan Institute of Nanotechnology & Advanced Materials (BINA)                                      Booth 6
Ben Gurion University                                         Booth 1-3
Meyer Burger (Germany) AG / Dashro trade Israel  Booth 32
Elbit SPONSOR
Getter Group Bio Med Scientific Division Booth 24
CST – Computer Simulation Technology AG  Booth 10
Kurt J. Lesker Company Booth 30
Mark Technologies Booth 29
MATIMOP                                                     Booth 22
Medent – Scientific Equipment Booth 4
Merck SPONSOR
Nano Instruments Booth 27
Nano Canada Booth 31
New Technology S.K Booth 5
NMPTeAm III               Booth 17
Qlight Nanotech SPONSOR
Rafael Advanced Defense Systems Ltd SPONSOR
RAMOT at Tel Aviv University Booth 21
Rhenium   Booth 18
Tortech Nano Fibers                  SPONSOR
The Center for NanoScience and Nanotechnology, Tel-Aviv University SPONSOR
The Ministry of Aliyah and Immigrant Absorption Booth 25
Technion – The Russell Berrie  Nanotechnology Institute Booth 28
TEMPUS Education Project Booth 7
V.I.S. Vacuum and Instrument Services- S.P.T. 3000 Scientific Products and Technology  Booth 26
Yissum Booth 23
   
   
   

  MATIMOP

 3G Solar Booth 22
Melodea Booth 22
NanoAir Booth 22
Nano Retina Booth 22
Vulcan Booth 22
Ray Techniques Booth 22
Callplant Booth 22
Elbit C4I Booth 22
KiloLambda Booth 22
Granalix Booth 22
Nano Dimension Booth 22
Nano Spun Booth 22
Tortech Booth 22
NanoPass Booth 22
NanoMaterials Booth 22
Ramot Booth 22
IAI Booth 22
CENS Booth 22
Tracense Booth 22

Israel Institute of Metals

 

 

 

Exhibition Application Form

untitled

 

 

To reserve your space, please contact Ms. Lyne An:

 

Phone: +972 -7-4745-7489

Email: Lan@kenes-exhibitions.com 

Exhibition Profile

The exhibition is open to all companies and organizations with products and services which are professional interest to the conference delegates.

 

Main Topics:

Information for Exhibitors

 

To download Exhibition Instructions:                                                           

 

click button

 

 

 

 

Download the Furniture Catalogue:

 

 

Catalogue-Button

 

 

 

How to Attend

EXHIBITION DETAILS

untitled

To reserve your space, please contact Ms. Lyne An:  

Phone: +972 -7-4745-7489

Email: Lan@kenes-exhibitions.com 

 

 

Space Allocation

The allocation of space will be on a first come first serve basis, according to the receipt of signed application forms accompanied by payment. Any space reservation made verbally, in writing or by application form without payment, will not be considered binding by the organizers.

 

 “Standard” stand construction – 4 sqm

Rental Fee: 3,500 NIS /$860 USD

 

 

Currency, VAT and Bank Charges

Previous Events

 nano 2014  

The 4th International Nanotechnology Conference & Exhibition NANO ISRAEL 2014

Visit the web site

 

 nano2012  

The 3rd International Nanotechnology Conference & Exhibition

March 26-27, 2012

Visit the web site

 

 nano2010

 The 2nd International NanoTechnology Conference –
NANO ISRAEL 2010 –
Israel, Tel Aviv, November 8-9, 2010.

Visit the web site

 

nano2009 

Nano Israel 2009
March 30-31, 2009 Inbal Jerusalem Hotel, Jerusalem, Israel
The Internation al NanoTechnology Conference
 Visit the web site

Website Link 

 

Picture Gallery

Nano In the Art Competition

 

EXHIBITION AND COMPETITION AT NANOISRAEL 2016 CONFERENCE

 

Following the success of NanoIsrael 2014, we are proud to host again an exhibition of works of art based on nanotechnology. The best Art work piece will be awarded, as judged by a jury of experts in the arts and sciences. 

Prof. Ron A. Nabarro acts as the Chair of the Selection Committee.

 

Ron Nabarro

Click here for CV

 

Nano art features nanolandscapes (molecular and atomic landscapes which are natural structures of matter at molecular and atomic scales) and nanosculptures (structures created by manipulating matter at molecular and atomic scales using chemical and physical processes). These structures are visualized with research tools like scanning electron microscopes and atomic force microscopes and their scientific images are captured and may be further processed by using different artistic techniques to convert them into artworks showcased for large audiences.

 

NanoIsrael 2016 participants wishing to submit, need to comply with the following:

 

2 files need to be emailed: One file with the art image in a high resolution good enough for print (MacIntosh files are not accommodated) and the second, a word.doc format, with text in answer to the following:  

Figure caption: A brief description of the scientific content 

Personal statement: free text describing your personal view of the scientific content, as depicted in the submitted image.  Files must be saved by participant’s name (Family Name_First Name). Both files must be saved with the same name.

To send by email to: lan@kenes-exhibitions.com

Submissions must be uploaded by January 31st, 2016

 

Ten posters only, will be selected for display at the NanoIsrael 2016 Conference. 

 

 

Kindly be aware that by sending your nano picture you will allow the organizers to use it for other PR publications after the event.

Prizes will be awarded during the closing ceremony on February 23, 2016.

Winners must be present in order to collect their prize. If winners are not present during the ceremony their win will be forfeited and given to the next best chosen work.

 

Call for Posters

NANO ABSTRACT SUBMISSION IS NOW   CLOSED_NEW

 

 

 

ABSTRACT SUBMISSION FOR POSTER PRESENTATION INSTRUCTIONS 

 

You are invited to submit an abstract to be reviewed for poster presentation at NanoIsrael 2016.

 

 

IMPORTANT NOTES FOR ABSTRACT PREPARATION AND SUBMISSION

 

  1. Prior to starting the abstract submission process, you should download the official template to be found in the on-line system and insert the text for your abstract. Complete the abstract and save it to your computer. The abstract will now be ready for upload to the submission system.
  2. Official confirmation of abstract submission will be emailed to all final submitted abstracts. If you have not received this confirmation then the abstract submission process is not yet complete and your abstract will not be sent for review.
  3. The abstract title should be the topic discussed in the abstract and not the Company name.
  4. To final submit/publish your abstract please use the following link login, select your open abstract,  click on the Summary tab at the top right of the page. If all information is correct, click the Publish button to be found on the bottom left of the Summary tab. 
  5. Please save your document as a doc.file and NOT a dox.file.
  6. Abstract submissions are limited is 320 words with a minimum of 130 words.
  7. Abstract submitter are requested to assign up to four key words of the list or suggest a new key word to be approved. (If nano-related industry, please include this key word)
  8. Poster presenters are requested to choose one category in the list.
  9. Uncommon abbreviations must be defined on first use. 
  10. Images, tables, diagrams and graphs should be JPG files. Images reduce the number of words allowed in your abstract text. Once the uploading and inserting of images into the abstract body is complete, the reduced number of words for abstract text will be advised. 
  11. In cases of genuine difficulties with uploading on the website, please contact the Organizer: cgelderbloem@kenes-exhibitions.com

 

CONDITIONS FOR ABSTRACT SUBMISSION

 

 

 

 

Topics

 

Meet The Speakers

 

PLENARY SPEAKERS  & KEYNOTE SPEAKERS

Prof. Toshio Ando, Kanazawa University, Japan

Prof. Louis Brus, Colombia University, USA

Prof. Bradley F. Chmelka, University of California, USA

Prof. Pieter  Cullis,  Ph.D, FRSC, Life Sciences Institute, University of British Columbia and NanoMedicines Research Group

Prof. Gitti Frey, Technion, Israel

Prof. Klaus Müllen, Max Planck Institute for Polymer Research, Germany

Prof. Eran Rabani, Berkeley, USA

Prof. Ronit Satchi Fainaro, Tel Aviv University, Israel

Prof. Oded Shoseyov, Hebrew University of Jerusalem, Israel

Prof. Yeshayahu (Ishi) Talmon, Technion-Israel Institute of Technology, Israel

 

 

INVITED SPEAKERS

Prof. Roy Bar Ziv, Weizmann Institute of Science, Israel

Prof. Smadar Cohen, Ben Gurion University, Israel

Dr. Ayelet David, Ben-Gurion University of the Negev, Israel

Dr. Barak Dayan, Weizmann Institute of Science, Israel

Dr. Tal Ellenbogen, Tel Aviv University, Israel

Dr. Dror Fixler, Bar Ilan University, Israel

Prof. Ilan Goldfarb, Tel Aviv University, Israel

Dr. Vered Padler-Karavani, Tel Aviv University, Israel

Dr. Ori Katz, The Hebrew University of Jerusalem, Israel 

Prof. Ron Lifshitz, Tel Aviv University, Israel

Prof. Oded Millo, Hebrew University of Jerusalem, Israel

Dr. Doron Naveh, Bar Ilan University, Israel

Dr. Gilbert Nessim, Bar Ilan University, Israel 

Prof. Dan Oron ,Weizmann, Institute of Science, Israel

Prof. Boaz Pokroy, Technion – Israel Institute of Technology, Israel

Dr. Meital Reches,  Hebrew University of Jerusalem, Israel

Prof. Roy Shenhar, Hebrew University of Jerusalem, Israel

Dr. Yonatan Sivan, Ben-Gurion University of the Negev, Israel

Dr. Oren Tal, Weizmann Institute of Science, Israel

Dr. Iris Visoily Fisher, Ben-Gurion University of the Negev, Israel

 

MEET THE INDUSTRY 

Dr. David Altreuter, Quiet Therapeutics

Mr. Shlomo Amir, Qlight

Mr. Barry N. Breen, 3G Solar Photovoltaics Ltd.

Dr. Ziv Gottesfeld, VoltaNano

Dr. Ziv Hermon, NanoAir

Dr. Shaul Lapidot , Melodea

Dr. Ricardo Osiroff, Tracense Systems

 

Full Program


Icon for Download Printable version of Program

Monday, 22 February 2016
 
    Hall A
09:00-09:20
Opening Remarks:                                                                                                                                                                                    
Mr. Rafi Koriat, INNI, Israel                                                                                                                                                                
Mr. Dan Vilenski, INNI, Israel
Welcome and Greetings, honored by:
Prof. Joseph Klafter, Tel Aviv University, Israel 
Mr. Avi Hasson, Ministry of Economy and Industry, Israel
 
09:20-10:00
 
SCIENCE FICTION OR SCIENCE, COMPUTING EVOLUTION AND MOORE’S LAW
 
Mr. Mooly (Shmuel) Eden
Former Senior V.P at Intel Corporation and President of Intel, Israel
10:00-10:40
SIZE, DIMENSIONALITY AND STRONG ELECTRON CORRELATION IN NANOSCIENCE
 
Prof. Louis Brus
Columbia University, USA
10:40-11:10
Coffee Break and Visit to Exhibition
 
Hall A
Hall B
Hall C
 11:10-13:00
Parallel Session  1 – Nano Medicine
Chair: Prof. Rimona Margalit 
Tel aviv University, Israel
Parallel Session 2 – Nano Energy
Chair: Prof. Gideon Grader
     
Technion , Israel
 
Parallel Session 3 – Nano Innovation and Policy 
Chair: Dr. Nili Mandelblit
ISERD, Israel
11:10-11:40
NOVEL CANCER MODELS-BASED IDENTIFICATION OF TARGETS FOR THE RATIONAL DESIGN OF PRECISION NANOMEDICINES

 

Prof. Ronit Satchi-Fainaro
Tel Aviv University, Israel 
ALL-OXIDE PHOTOVOLTAICS: A COMBINATORIAL MATERIAL SCIENCE STUDY

 

Prof. Arie Zaban
Bar Ilan University, Israel 
NANOTECHNOLOGY POLICY AND INNOVATION IN HORIZON 2020
Download Lecture Presentation
 
Mr. Jyrki Suominen
European Commission, Belgium
11:40-12:00
LIGAND-TARGETED POLYMER-DRUG CONJUGATES FOR INHIBITION OF PRIMARY AND METASTATIC TUMORS IN MICE

 

Dr. Ayelet David
Ben Gurion University, Israel 
INTRODUCING CARBON-NANO TECHNOLOGY INTO AN ULTRA-ORTHODOX INDUSTRY: THE LEAD ACID BATTERY CASE STUDY
Download Lecture Presentation

 

Mr. Ziv Gottesfeld
VoltaNano, Israel 
SMART CERAMIC MATERIALS FOR ENERGY AND ENVIRONMENTAL TECHNOLOGY

 

Prof. Alexander Michaelis
Fraunhofer IKTS, Germany
12:00-12:20
GAGOMERS, TUMOR-TARGETED NANOPARTICLES; DELIVERING ON A PROMISE OF BETTER CANCER THERAPIES

 

Dr. David Altreuter
Quiet Therapeutics Inc., Israel-USA
HONEYCOMB 3D-MICROBATTERIES

 

Prof. Diana Golodnitsky
Honeycomb Batteries, Israel
NOVEL OPPORTUNITIES FOR PHOTONICS BASED ON SEMICONDUCTOR NANOSTRUCTURES AND QUANTUM EFFECTS

 

Prof. Jean-Michel Gerard
CEA, France
12:20-12:40
A BRIDGE TO SILENCING: CO-ASSEMBLING ANIONIC NANOPARTICLES OF SIRNA AND HYALURONAN SULFATE VIA CALCIUM BRIDGES

 

Prof. Smadar Cohen
Ben Gurion University, Israel
POWERING WIRELESS ELECTRONICS WITH DYE

 

Mr. Barry Breen
3GSolar Photovoltaics Ltd, Israel
 
NANOTECHNOLOGY AT THE NATIONAL RESEARCH COUNCIL OF ITALY
 
Prof. Corrado Spinella
CNR, Italy

 

12:40-13:00
TARGETING THE SWEET SIDE OF CANCER WITH GLYCO-NANOPARTICLE
 
Dr. Vered Karavani
Tel Aviv University, Israel 
 

DESIGN OF NANOSTRUCTURES FOR  ENERGY AND ENVIRONMENTAL APPLICATIONS

 

Prof. Ashok Kumar Ganguli
Institute of Nano Science and Technology, India
 MULTI-TECHNOLOGY ADDITIVE MANUFACTURING FOR 3D STRUCTURAL ELECTRONICS
Download Lecture Presentation
 
Dr. Erwin Meinders
TNO, The Netherlands
13:00-14:20
Lunch Break and Visit to Exhibition
14:20-15:40
Poster Session 1 (Poster Hall)
 
Hall A
Hall B
Hall C
 15:40-17:10
Parallel Session  4 – Nano Physics 
Chair: Prof. Uri Sivan
                   
Technion, Israel  
Parallel Session  5 – Nano Material Synthesis and Characterization
Chair: Prof. Yuval Golan
Ben Gurion University, Israel
 
Parallel Session  6 – International Nano Cooperation
Chair: Mr. Dan Vilenski  
INNI, Israel

 

 

 

15:40-16:10
MULTIEX CITON GENERATION AT THE NANOSCALE
Download Lecture Presentation
 
Prof. Eran Rabani
University of California, USA
SURFACE COMPOSITIONS, STRUCTURES, AND PROPERTIES OF SURFACTANT-DIRECTED NANOSCALE SEMICONDUCTORS

 

Prof. Bradley F.Chmelka
University of CA Santa Barbara, USA
 A MACRO VIEW ON NANO
Download Lecture Presentation
 
Prof. Eugene Kandel
Start-up Nation Central (SNC), Israel
16:10-16:30
RECENT ADVANCES IN BORON NITRIDE NANOTUBES: MANUFACTURING, CHEMISTRY, COMPOSITES AND APPLICATIONS
Download Lecture Presentation

Dr. Benoit Simard
National Research Council, Canada
LESSONS LEARNED FROM CARBON NANOTUBE GROWTH CAN BE APPLIED TO GRAPHENE: 100% REPRODUCIBILITY AND IMPROVED GRAPHENE QUALITY BY PREHEATING PRECURSOR GASES USING THERMAL CHEMICAL VAPOR DEPOSITION
 
Dr. Gilbert Daniel Nessim 
Bar Ilan University, Israel
MATERIALS INNOVATION AT MERCK:  NAVIGATING THE HYPE CYCLE 

 

Dr. Brian Daniels
Merck KGaA, Germany                                                                        
                                                                       
16:30-16:50
ELECTRONIC PROPERTIES OF CU-CHALCOGENIDES BASED SYSTEMS: FROM NANOCRYSTALS TO THIN-FILM SOLAR CELLS
 
Prof. Oded Millo
The Hebrew University
of Jerusalem, Israel
HIERARCHICALLY-ORDERED NANOPARTICLE/BLOCK COPOLYMER FILMS: INCREASING OUR CONTROL OVER MORPHOLOGICAL PARAMETERS
 
Prof. Roy Shenhar
The Hebrew University
of Jerusalem, Israel
NETHERLANDS NANO INITIATIVE: STRATEGIC RESEARCH AGENDA TOWARDS APPLICATIONS
Download Lecture Presentation
 
Prof. D.H.A. Blank 
NanoNetNL, The Netherlands
16:50-17:10
QUANTUM MATERIAL FOR WIDE COLOR-GAMUT DISPLAY

 

Mr. Shlomo Amir
Qlight Nanotech Ltd, Israel
PROGRAMMABLE ON-CHIP DNA COMPARTMENTS AS ‘ARTIFICIAL CELLS’

 

Prof. Roy Bar Ziv
Weizmann Institute of Science, Israel
NANOMATERIALS DEVELOPMENT AND COMMERCIALIZATION AT 3M

 

Dr. Michal Vakrat Wolkin
3M, Israel
17:10-17:30
Coffee Break and Visit to Exhibition
17:30-18:10
Plenary Session 2  Hall A                                                                                                                                                                               
Chair: Prof. Dan Peer, Tel Aviv University, Israel

 

LIPID NANOPARTICLE SYSTEMS FOR IN VIVO DELIVERY OF SIRNA AND MRNA
 

Prof. Pieter R Cullis

University of British Columbia, Canada
           
Tuesday, 23 February 2016
 
Plenary Session 3 – Hall A                                                                                                                                                                              
Chair: Prof. Yael Hanein, Tel Aviv University, Israel
09:00-09:40
CHEMICAL ROUTES TO NANOGRAPHENES

 

Prof. Klaus Müllen
Max Planck Institute, Germany
09:40-10:20
NANO BIO MIMETICS: MATERIALS FOR THE FUTURE
Download Lecture Presentation

 

Prof. Oded Shoseyov
The Hebrew University of Jerusalem, Israel
10:20-10:50
Coffee Break and Visit to Exhibition
 
Hall A
Hall B
Hall C
 10:50-12:50
Parallel Session  7 – Bio Materials 
Chair: Prof. Reshef Tenne, 
Weizmann Institute of Science, Israel 
Parallel Session  8 – Nano Photonics
Chair: Dr. Moshe Oron 
Kilolambda Technologies Ltd, Israel                  
 
 
Parallel Session  9 – Nano Defense
Chair: Mr. Ophir Shoham 
MAFAT , Israel
 

 

10:50-11:20
NANOSCIENCE AND HUMAN DISEASE

Sir  Mark Welland 
University of Cambridge, England
LIGHT MANIPULATION IN BIOLOGICAL SYSTEMS AT THE MICRO- AND NANOSCALE

 

Prof. Dan Oron
Weizmann Institute of Science, Israel 
NANO TECHNOLOGY IN DEFENSE IN ISRAEL

 

Dr. Amir Uziel & Dr. Ehud Galun
IMOD, MAFAT, Israel

11:20-11:50
AN ELECTRON MICROSCOPY VIEW OF NANOSTRUCTURE FORMATION BY SELF-AGGREGATION

 

Prof. Yeshayahu Talmon
Technion, Israel
NEW ASPECTS OF THE THERMAL NONLINEARITY OF METALS

 

Dr. Yonatan Sivan
Ben Gurion University, Israel
CURRENT RESEARCH AT THE NAVAL RESEARCH LABORATORY NANOSCIENCE INSTITUTE

 

Dr. Igor Medintz
NRL Nano Institute, USA
11:50-12:10
HOW DO PEPTIDES SENSE A SURFACE: FUNDAMENTALS AND APPLICATIONS

 

Dr. Meital Reches
The Hebrew University
of Jerusalem, Israel
MANIPULATION OF HARMONICS AND HYBRID LIGHT-MATTER STATES WITH OPTICAL METASURFACES
Download Lecture Presentation
 
Dr. Tal Ellenbogen
Tel Aviv University, Israel 
SELECTED ACTIVITIES OF WIWEB IN THE FIELD OF NANOTECHNOLOGY

 

Dr. Ines Schneider
German Defense Office, Germany
12:10-12:30
BIO-INSPIRED CRYSTAL GROWTH: FROM BAND GAP ENGINEERING TO SINGLE CRYSTALLINE NANO-POROUS GOLD

 

Prof. Boaz Pokroy
Technion, Israel
SEEING THROUGH THE FOG: LOOKING INTO OPAQUE SAMPLES AND AROUND CORNERS WITH SCATTERED LIGHT
 
Dr. Ori Katz
The Hebrew University
of Jerusalem, Israel
OPPORTUNITIES IN NANOSTRUCTURES AND NANOMATERIALS FOR DEFENSE APPLICATIONS
Download Lecture Presentation
 
Mr. Bruno Mortaigne
The French Defence (DGA), France
12:30-12:50
NANO CRYSTALLINE CELLULOSE (NCC), BIO-BUILDING BLOCKS FOR TOMORROW’S MATERIALS

 

Dr. Shaul Lapidot
Melodea, Israel
NANO-THERANOSTICS WITH PLASMONIC NANOPARTICLES: GOD EXISTS IN THE SMALL DETAILS
Download Lecture Presentation
 
Dr. Dror Fixler
Bar Ilan University, Israel
 
NANOTECHNOLOGY FOR THE DEFENSE SECTOR IN CANADA
Download Lecture Presentation
 
Dr. Marie D’Iorio
National Institute for Nanotechnology (NINT), Canada
                                                              
 
12:50-14:10
Lunch Break and Visit to Exhibition
14:10-15:30
Poster Session 2 (Poster Hall)
 
Hall A
Hall B
Hall C
 
Hall D
 15:30-17:30
Parallel Session  10 – Nano Electronics 
Chair: Prof. Yuval Garini  
Bar Ilan University, Israel
Parallel Session  11 – Nano Mechanics
Chair: Prof. Dov Sherman
Tel-Aviv University, Israel
 
Parallel Session  12 – Nano Sensors
Chair: Prof.
Uriel Levy
The Hebrew University of Jerusalem, Israel
 
 
Parallel Session  13 – Nano Education
Chair: Mr. Haim Rousso                      
Elbit, Israel
 
15:30-16:00
THE “INSTABILITY” OF ORGANIC SOLAR CELLS – TURNING DISADVANTAGES INTO ADVANTAGES

 

Prof. Gitti Frey
Technion, Israel 
TOWARDS QUANTUM NANOMECHANICS

 

Prof. Ron Lifshitz
Tel Aviv University, Israel 
NANO-TO-KILO DEVICE FIBERS

 

Prof. Yoel Fink
MIT, USA
16:00-16:10
School Project 1
16:00-16:20
NANOSTRUCTURED PHOTOVOLTAIC DEVICES VIA WET PROCESSING OF ORGANIC AND INORGANIC MATERIALS

 

Dr. Iris Visoly Fisher
Ben Gurion University, Israel 
CAN INORGANIC NANOTUBES REPLACE CARBON NANOTUBES IN POLYMER NANOCOMPOSITES?

 

Prof. Samuel Kenig
Shenkar College of Engineering and Design, Israel
CMOS COMPATIBLE GAS SENSOR BASED ON ELECTROSTATICALLY FORMED NANOWIRES

 

Prof. Yossi Rosenwaks
Tel Aviv University, Israel
16:10-16:30
MASSIVE OPEN ONLINE COURSE IN NANOTECHNOLOGY AND NANOSENSORS:         PROMOTING INNOVATIVE THINKING AND MOTIVATION TO LEARN AMONG  INTERNATIONAL LEARNING TEAMS  
                  
Prof. Hossam Haick
Technion, Israel
16:20-16:40
WHAT LIMITS THE CONDUCTION OF METAL-MOLECULE JUNCTIONS?

 

Dr. Oren Tal
Weizmann Institute of Science, Israel 
NANOAIR – PAPER THIN ACTIVE COOLING SOLUTIONS FOR CHIPS AND ELECTRONIC DEVICES

 

Dr. Ziv Hermon
Nano Air, Israel 
DETECTION AND IDENTIFICATION OF EXPLOSIVES USING LARGE-SCALE ARRAYS OF CHEMICALLY-MODIFIED ELECTRICAL NANO-SENSORS
Download Lecture Presentation
 
Mr. Noam Noy
Tracense Systems Ltd, Israel
16:30-16:40
School Project 2
16:40-17:00
2D LAYERED MATERIALS FOR NANO-ELECTRONICS

 

Dr. Doron Naveh
Bar Ilan University, Israel 
3D PRINTING OF DISSIMILAR MATERIAL STRUCTURES
 
Prof. Marcelo Dapino
The Ohio State University, USA
NEW SENSORS APPROACH BASED ON ULTRA-LONG CNTS FIBERS & MATS

 

Dr. Shuki Yeshurun 
Tortech Nano Fibers Ltd, Israel
16:40-17:00
PARTICIPATION OF HIGH SCHOOL STUDENTS IN SCIENTIFIC CONFERENCES: THE CASE STUDY OF NANOISRAEL 2014

 

Dr. Ron Blonder
Weizmann Institute of Science, Israel
17:00-17:20
TOWARDS NEW GENERATION NON-VOLATILE MEMORY CELLS

 

Prof. Ilan Goldfarb
Tel Aviv University, Israel 
NANOSPUN BIO-FIBROUS STRUCTURE FOR IMPROVED BIOLOGICAL PROCESSES

 

Dr. Yael Dror
NanoSpun Technologies, Israel 
CHALLENGES IN THE DEVELOPMENT OF NANOMEDICINES: RELEVANCE TO FUTURX, THE ISRAELI BIOTECHNOLOGY INCUBATOR

 

Dr. Einat Zisman
FutuRx Incubator, Israel
17:00-17:10
School Project 3
       
 17:10-17:30
EDU-NANO: AN INTERNATIONAL PARTNERSHIP FOR NANOSCIENCE E-LEARNING

 

Dr. Efrat Bodner
Bar Ilan University, Israel 
17:20-17:40
Coffee Break and Visit to Exhibition
 17:40-18:10
Awarding of The Tenne Family Prize to Prof. Taleb Mokari,
Best Poster Award,
Nano Art Award,
Company / Innovation of the year Award  
 
Plenary Session 4 – Hall A                                                                                                                                                                            
Chair: Prof. Ori Cheshnovsky, Tel Aviv University, Israel
 18:10-18:50
NANO-VISUALIZATION OF BIOMOLECULES IN DYNAMIC ACTION BY HIGH-SPEED ATOMIC FORCE MICROSCOPY

 

Prof. Toshio Ando
Kanazawa University, Japan
18:50-19:00
Closing Remarks

Welcome Letter

 

Dear Colleagues,

 

We are excited to invite you to join us at the NanoIsrael 2016, the fifth bi-annual conference & exhibition, to be held in Tel Aviv on 22-23 February, 2016.

Israel is renowned for its achievements in innovative products and solutions.  Over the past decade Israel has also established itself as a key player in nanotechnology, providing new and exciting opportunities and solutions in materials, medical, mobile, defense & aerospace, semi-conductor and other important and emerging industrial sectors.

 

Join us to meet the top researchers and leaders from Israel and abroad and to gain a first look at cutting-edge technologies, leading scientific achievements and unique business and investment opportunities.

 

NanoIsrael has established itself as the central meeting point for local and multinational companies, investors, university and corporate research scientists and government representatives from around the world. Bringing together elite speakers and top individuals from academia, business and government, the forth conference held in Tel Aviv in March 2014 drew over 1400 delegates from Israel and abroad that were able to review the full range of cutting-edge technologies. From scientific innovation presented by top scientists and speakers, through “Golden Nuggets”, technologies on the verge of commercialization, dozens of innovative start-ups, multinationals seeking collaborations, top defense related bodies from Israel and the USA, a Nano-Education session, government agencies and a display of 20 of the latest innovations and products.

 

NanoIsrael 2016 is held in cooperation with the Israel National Nanotechnology Initiative (INNI), the Nanotechnology centers at Israeli universities along with the Ministries of Economy and Foreign Affairs and key industry players.

 

We look forward to welcoming you in Tel Aviv.

 

Sincerely,

Prof. Ori Cheshnovsky 

Prof. Yael Hanein

Mr. Rafi Koriat

Co-Chairpersons, NanoIsrael 2016

 

 

Nano-Energy

[22] DIRECT FORMATION OF HOT ELECTRON INJECTING NANOSTRUCTURES FOR PHOTOVOLTAICS

 

Hannah Noa Barad1, Adam Ginsburg2, Kevin Rietwyk2, Hagai Cohen3, David A Keller4, Shay Tirosh2, Assaf Anderson2, Arie Zaban2

1 Bar Ilan University; Department of Chemistry
2 Bar Ilan University; Bar Ilan University
3 Weizmann Institute of Science; Weizmann Institute of Science
4 Bar-Ilan University; Bar-Ilan University

Direct Formation of Hot Electron Injecting Nanostructures for Photovoltaics
Hannah-Noa Barada, Adam Ginsburga, Kevin J. Rietwyka, Hagai Cohenb, David A. Kellera, Shay Tirosha, Assaf Y. Anderson*,a, and Arie Zaban*,a
aDepartment of Chemistry and the Nanotechnology and Advanced Materials Center, Bar Ilan University, Ramat Gan
bDepartment of Chemical Research Support, Weizmann Institute of Science, Rehovot
assaf.anderson@gmail.com, arie.zaban@biu.ac.il
TiO2, a photoactive semiconductor (Eg= 3.2 eV), cannot generate enough current to sustain power in a photovoltaic device due to its limited spectral activity. Typically it is used in conjunction with light absorbing materials that extend the spectral response of the photovoltaic device. Recently, it was shown that plasmonic nanoparticles can inject hot electrons into TiO2 and extend the photovoltaic spectral response. However, in order to obtain these nanoparticles, their formation requires either patterning or special preparation techniques. Furthermore, to complete the solar cell structure usually a hole transport material is used.
We prepared a solid state plasmonic solar cell, based on TiO2 and Ag, without complicated nanoparticle deposition techniques and with no hole transport material. To obtain these solar cells, silver was deposited with different thicknesses by sputtering as a back contact for the solar cells. The silver nanostructures are formed by the rough nature of the TiO2. The Ag has a dual role both as the current conductor and as the metal forming a Schottky barrier. The Ag generates hot electrons upon illumination, injected into the TiO2, enhancing the photovoltaic activity of the solar cells. We provide evidence for the plasmonic photovoltaic activity by performing IPCE measurements that show a current onset at around 700 nm, while XPS reveals a wide-spread plasmonic peak. I-V measurements show photovoltaic activity dependent on the Ag back contact thickness. The best cell performances give short circuit currents of 1.18 mA cm-2 and open circuit voltages of 400 mV. To our knowledge the obtained currents are much higher than any previous report for TiO2/Ag solar cells.

 

[34] SOLAR ENERGY DRIVEN SOLID STATE FERMENTATION FOR CONTINUOUS FLOW BIOETHANOL PRODUCTION

 

Betina Tabah1

1 Bar-Ilan University; Department of Chemistry and Bar-Ilan Institute of Nanotechnology and Advanced Materials (Bina)

Betina Tabah, Indra Neel Pulidindi, Aharon Gedanken*
Department of Chemistry and Bar-Ilan Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan 52900, Israel

* Corresponding author:
e-mail: gedanken@mail.biu.ac.il
ABSTRACT
The focus of the present research is to develop energy efficient, sustainable, and continuous flow bioethanol production based on solar energy. Solid state fermentation of glucose was performed in a specially designed solar energy driven reactor. Produced ethanol was separated from the yeast bed soon after its formation by an evaporation-condensation process. When aqueous glucose solutions of 10 and 20 wt. % were fed into the reactor bed containing the Baker’s yeast (Saccharomyces cerevisiae), 4.7 and 8.7 wt. % ethanol yields were obtained, respectively. High ethanol yields (91.2 and 85.5 % of the theoretical yield, respectively) indicate the atom efficiency of the process. No loss in the activity of yeast was observed even after two months of continuous operation of the solar reactor. The ethanol produced from 20 wt. % feed (ca. 2 M) was demonstrated as a potential fuel for direct ethanol fuel cells. The use of non-noble metal electrode catalysts for the operation of the fuel cell for electricity generation makes the methodology innovative and economically feasible. Thus, the current study demonstrates an energy efficient methodology for bioethanol production utilizing the solar energy.

 

[44] SELECTIVE PRODUCTION OF GLUCOSE FROM RICE STRAW USING SOLID ACID CATALYST UNDER MICROWAVE IRRADIATION

 

Amudhavalli Victor1

1 Bar-Ilan University; Chemistry Department

Amudhavalli Victor, Indra Neel Pulidindi, Aharon Gedanken*
Department of Chemistry and Bar-Ilan Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan 52900, Israel

* Corresponding author:
e-mail: gedanken@mail.biu.ac.il

The problems of environmental deterioration as well as energy demands could be alleviated by the paradigm shift to the use of biofuels from fossil fuels. Innovative strategies were developed recently for the exploitation of biomass for biofuels production. A selective, green and fast method for the production of glucose from the rice (Oryza Sativa) straw is demonstrated. Aq. ammonia based pretreatment techniques played a crucial role in the removal of lignin and xylan from rice straw which in-turn accelerated glucan hydrolysis and improved the selectivity of glucose production. The cellulose isolated from rice straw was further hydrolyzed to glucose using a solid acid catalyst (activated carbon supported phosphotungstic acid, 40 wt. % HPW/AC). Microwave irradiation of cellulose from rice straw for a short duration of 5 min. at 100 °C yielded 11.2 wt.% glucose relative to 8 wt.% glucose produced from hydrothermal hydrolysis process (3 h, 150 °C) with a substrate to catalyst wt./wt. ratio of 1. Thus an effective biomass pretreatment (aq. ammonia – dil. H2SO4) method and an accelerated and selective biomass hydrolysis process were developed.

 

[56] PEROVSKITES FOR PHOTOVOLTAICS IN THE SPOTLIGHT: PHOTOINDUCED PHYSICAL CHANGES AND THEIR IMPLICATIONS

 

Ronen Gottesman1, Arie Zaban1

1 Bar Ilan University; Bar Ilan University

Perovskites for Photovoltaics in the Spotlight: Photoinduced Physical Changes and Their Implications
Ronen Gottesman* and Arie Zaban
Department of Chemistry, Center for Nanotechnology & Advanced Materials,
Bar-Ilan University, Ramat Gan 52900, Israel.
ronen.gottesman@gmail.com
Organic-inorganic halide perovskites are in consensus to revolutionize the field of photovoltaics and optoelectronic devices due to their superior optical and electronic properties which are unprecedented in comparison to those of other solution processed semiconductors. These hybrid materials are used as light absorbers and also as charge carries which makes them very versatile to be implemented and studied in multitude of fields. Traditionally, the working paradigm in solar cells and optoelectronic devices’ characterization has been that the properties of photovoltaic materials remain stable following illumination of varying times and intensities. However, a growing number of reports on prolonged illumination-dependent physical changes (photoinduced changes) in perovskite films and perovskite based devices. The changes are reversible and range from structural transformations and differences in optical characteristics, to an increase in optoelectronic properties and physical parameters.
We review photoinduced changes in three reported model systems which display changes under prolonged illumination. The systems are: i) a free-standing perovskite film on a glass substrate, ii) a symmetrical system with non-selective electrical contacts, iii) a working perovskite solar cell. The photoinduced changes of each model system are discussed along with the implications on future experimentation design, data analysis and characterization that involve organic-inorganic halide perovskites illumination.

 

[68] FERROELECTRICITY FOR ALL-OXIDE PHOTOVOLTAICS- STUDY OF BI2O3 AND BIMNO3 FABRICATED BY SPRAY PYROLYSIS

 

Adam Ginsburg1, David A Keller2, Hannah Noa Barad3, Kevin Rietwyk4, Assaf Anderson4, Arie Zaban4

1 Bar-Ilan University; Anna&max Webb
2 Bar-Ilan University; Bar-Ilan University
3 Bar Ilan University; Department of Chemistry
4 Bar Ilan University; Bar Ilan University

Recently, ferroelectric materials draw significant interest as possible materials for photovoltaics. This is due to their unique property – Its ability to remain polarized after the application of an external electric field. This property was reported to allow an internal electric filed that drives charge separation within a single material, as opposed to p-n heterojunction, where the field is formed in the junction between two materials.
In this work, spray pyrolysis of Bi2O3 and BiMnO3, both reported ferroelectric materials, were fabricated by spray pyrolysis and were tested for their photovoltaic properties both as a single materials, and in a junction configuration. So far reaching a voltage higher than 1.1V. In addition, a full characterization of the film is performed in order to discover the crystal phase (XRD), and the optical properties of the film.

 

[71] OXIDE ABSORBER MATERIALS FOR ALL-OXIDE PHOTOVOLTAICS

 

Koushik Majhi1

1 Bar Ilan Institute of Nanotechnology and Advanced Materials (Bina); Bar-Ilan

Oxide Absorber materials for All-Oxide Photovoltaics
Koushik Majhi*, Assaf Anderson, Hannah-Noa Barad, Kevin Rietwyk, Adam Ginsburg, David Keller, Yaniv Bouhadana, Zhi Yan, Eli Rosh-Hodesh, Arie Zaban
* Presenting author. E-mail: koushik.majhi@biu.ac.il
Combinatorial synthesis in conjunction with high-throughput (HT) methods have been developed to synthesize novel thin-film absorber materials for low cost all oxide photovoltaics.1 Most metal oxides (MOs) have a bandgap in the UV part of the solar spectrum and it is the aim of the project to synthesize and identify novel multi-component MOs with a band gap at lower energies. Continuous compositional spreads of metal oxides were synthesized via pulsed laser deposition (PLD) and high throughput techniques were used to study optical structural, optical and electrical properties as a function of composition. The optical transmission spectra of mixed multi-component metal oxides show enhanced light absorption in the visible range. The crystal structure as a function of composition was characterized using scanning XRD and Raman spectroscopy. Application of such light absorbers in PV devices show improved performance compared to the pure metal oxide components of the absorber.
References:
1. Rühle, S.; Anderson, A. Y.; Barad, H.-N.; Kupfer, B.; Bouhadana, Y.; Rosh-Hodesh, E.; Zaban, A. All-Oxide Photovoltaics. J. Phys. Chem. Lett. 2012,3, 3755–3764

 

[84] MAGNETISM IN OLIVINE-TYPE LICO1-XFEXPO4 CATHODE MATERIALS: BRIDGING THEORY AND EXPERIMENT

 

Yelena Gershinsky1, David Zitoun2

1 Bar Ilan Institute of Nanotechnology and Advanced Materials (Bina); Bar Ilan Institute of Nanotechnology and Advanced Materials (Bina)
2 Bar Ilan University; Chemistry and the Institute for Nanotechnology and Advanced Materials, Bar-Ilan University

Magnetism in Olivine-type LiCo1-xFexPO4 Cathode Materials: Bridging Theory and Experiment

Yelena Gershinsky § and David Zitoun*
Vijay Singh,§ Monica Kosa, Mudit Dixit, Dan Thomas Major*

Department of Chemistry and the Lise Meitner-Minerva Center of Computational Quantum
Chemistry and the Institute for Nanotechnology and Advanced Materials, Bar-Ilan University
§ Equal contribution
* Electronic mail: majort@biu.ac.il, david.zitoun@biu.ac.il

In the current work, we present a non-aqueous sol-gel synthesis of olivine type LiCo1-xFexPO4 compounds (x = 0.00, 0.25, 0.50, 0.75, 1.00). The magnetic properties of the olivines are measured experimentally and calculated using first-principles theory. Specifically, the electronic and magnetic properties are studied in detail with standard density functional theory (DFT), as well as by including spin-orbit coupling (SOC), which couples the spin to the crystal structure. We find that the Co2+ ions exhibit strong orbital moment in the pure LiCoPO4 system, which is partially quenched upon substitution of Co2+ by Fe2+. Interestingly, we also observe a non-negligible orbital moment on the Fe2+. We underscore that the inclusion of SOC in the calculations is essential to obtain qualitative agreement with the observed effective magnetic moments. Additionally, Wannier functions were used to understand the experimentally observed rising trend in the Néel temperature, which is directly related to the magnetic exchange interaction paths in the materials. We suggest that out of layer M – O – P – O – M magnetic interactions (J⊥) are present in the studied materials. The current findings shed light on important differences observed in the electrochemistry of the cathode material LiCoPO4 compared to the already mature olivine material LiFePO4.
(Paper submitted to Physical Chemistry Chemical Physics)

 

[100] A LAYERED-SPINEL COMPOSITE CATHODE LINI0.33MN0.54CO0.13O2 WITH VERY GOOD CYCLING STABILITY FOR LI-ION BATTERIES

 

Prasant Nayak1, Judith Grinblat1, Mikhael Levi1, Elena Levi1, Doron Aurbach1

1 Bar-Ilan University; Bar-Ilan University

A layered-spinel composite cathode LiNi0.33Mn0.54Co0.13O2 with very good cycling stability for Li-ion batteries
Prasant Kumar Nayak, Judith Grinblat, Mikhael Levi, Elena Levi, Doron Aurbach*
Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel 5290002

Abstract
A layered-spinel composite LiNi0.33Mn0.54Co0.13O2 is synthesized by self-combustion reaction (SCR) and studied as a cathode material for Li-ion batteries. The Rietveld analysis of LiNi0.33Mn0.54Co0.13O2 indicates the presence of monoclinic Li[Li1/3Mn2/3]O2 (31%) and rhombohedral (LiNixMnyCozO2) (62 %) phases as the major components with spinel (LiNi0.5Mn1.5O4) (7 %) as a minor component, which is well supported by TEM and electron diffraction. Its electrochemical performance is compared with that of the layered cathode material LiNi0.33Mn0.33Co0.33O2 in a wide potential window of 2.3-4.9 V vs. Li/Li+. A discharge specific capacity of about 170 mAh g-1 is obtained in the potential range of 2.3-4.9 V vs. Li at low rate (C/10) with excellent capacity retention upon cycling. On the other hand, LiNi0.33Mn0.33Co0.33O2 (NMC111) synthesized by SCR exhibits an initial discharge capacity of about 208 mAh g-1 in the potential range of 2.3-4.9 V, which decreases to a value of 130 mAh g-1 after only 50 cycles. Thus, the presence of spinel in multiphase structure of LiNi0.33Mn0.54Co0.13O2 seems to stabilize the behavior of this cathode material even when polarized to high potentials. The excellent cyclability of LiNi0.33Mn0.54Co0.13O2 can be ascribed to the suppression of layered-to-spinel phase transformation due to presence of a spinel component LiNi0.5Mn1.5O4 in the pristine active mass. Also, LiNi0.33Mn0.54Co0.13O2 shows superior retention of average discharge voltage upon cycling as compared to LiNi0.33Mn0.33Co0.33O2 when cycled in such a wide potential range.

 

[103] PHOTO-INDUCED REVERSIBLE STRUCTURAL TRANSFORMATIONS IN FREE STANDING CH3NH3PBI3 PEROVSKITE FILMS

 

Ronen Gottesman1, laxman gouda1, Basanth S. Kalanoor1, Eynav Haltzi1, Shay Tirosh1, Eli Rosh Hodesh2, Yaakov Tischler3, Arie Zaban1, Claudio Quarti4, Filippo De Angelis4

1 Bar Ilan University; Bar Ilan University
2 Dept. Chemistry; Nanotechnology
3 Bar-Ilan Institute of Nanotechnology and Advanced Materials; Bar-Ilan University
4 Computational Laboratory for Hybrid/Organic Photovoltaics (Clhyo); Computational Laboratory for Hybrid/Organic Photovoltaics (Clhyo)

Abstract:
In the pursuit to better understand the mechanisms of perovskite solar cells we performed Raman and Photoluminescence measurements of free standing CH3NH3PbI3 films, comparing dark with working conditions. The films, grown on a glass substrate and sealed by a thin glass cover slip, were measured subsequent to dark and white light pretreatments. The extremely slow changes we observe in both the Raman and Photoluminescence cannot be regarded as electronic processes which are much faster. Thus, the most probable explanation is of slow photo-induced structural changes. The CH3NH3PbI3 transformation between the dark and the light structures is reversible, with faster rates for the changes under illumination. The results seem to clarify several common observations associated with solar cell mechanisms, like performance improvement under light soaking. More important is the call for solar cell related investigation of CH3NH3PbI3 to take the photo-induced structural changes into consideration when measuring and interpreting the results.

 

[104] UNRAVELING OPPOSING OPERATING MECHANISMS IN MULTI-LAYERED ALL-OXIDE PHOTOVOLTAIC CELLS

 

David A Keller1, Koushik Majhi2, Kevin Rietwyk3, Adam Ginsburg4, Hannah Noa Barad5, Zhi Yan3, Yaniv Bouhadana6, Eli Rosh Hodesh6, Assaf Anderson3, Arie Zaban3

1 Bar-Ilan University; Bar-Ilan University
2 Bar Ilan Institute of Nanotechnology and Advanced Materials (Bina); Bar-Ilan
3 Bar Ilan University; Bar Ilan University
4 Bar-Ilan University; Anna&max Webb
5 Bar Ilan University; Department of Chemistry
6 Dept. Chemistry; Nanotechnology

Unraveling Opposing Operating Mechanisms in Multi-layered All-Oxide Photovoltaic Cells
David A Keller, Koushik Majhi, Kevin J. Rietwyk, Adam Ginsburg, Hannah-Noa Barad, Zhi Yan, Yaniv Bouhadana, Eli Rosh-Hodesh, Assaf Y Anderson and Arie Zaban
Chemistry department and the center for nanotechnology and advanced materials, Bar-Ilan University, Ramat-Gan, Israel, 5290002
dkeller@walla.co.il
A promising family of photovoltaic solar cells, based solely on metal oxide thin films, has recently been gaining interest. To improve the inadequate electrical properties of the pure metal oxide materials, various metal oxides are mixed, to create new composite materials that may exhibit enhanced properties. The new materials are then examined as light absorbing layers in photovoltaic cells, stacked between other metal oxide layers in multi-layered structure. The structure is consisting of different metal oxide layers: transparent conductive layer, electron transport layer, absorber layer and hole transport layer. Because of the multi-layered structure, it is difficult to resolve the operating mechanism of these solar cells.
To meet this need, a home-built high-throughput incident photon to current efficiency (IPCE) measuring system was constructed. Using the new system and other high-throughput optical, electrical and structural scanning systems, we thoroughly studied the operating mechanisms of several all-oxide samples, including composite materials of Fe2O3, Co3O4, Bi2O3, TiO2 and others. In many of the cells we found evidence for two distinct processes with different operating mechanisms. The two mechanisms may work in parallel, compete, or even counter each other. As for their origin, the two mechanisms may result from photovoltaic activity of two different layers, or alternatively from activity of two separate bandgaps within the same material.
Once the different mechanisms are understood, it is possible to enhance or to suppress one of them. This will allow for further improvement of the all-oxide cells’ photovoltaic performance.

 

[111] THE EFFECT OF ORGANIC LIGANDS ON SI NANOPARTICLES AS ANODE MATERIAL FOR LI ION BATTERY

 

Gal A Grinbom1

1 Bar Ilan University; Bar Ilan University

The effect of Organic ligands on Si Nanoparticles as anode material for Li ion battery
Gal Grinbom and David Zitoun

Department of Chemistry, Bar Ilan Institute of Nanotechnology and Advanced Materials (BINA), Ramat Gan 52900, Israel
Batteries are valuable electrochemical cells and play an important role in the green energy strategies. Typical Electrochemical cell is composed of many components that affect each other. In this study, we focus on understanding the contribution of organic ligands decorating Si nanoparticles (NPs) surface. These Organic ligands can affect: the solid-electrolyte interface (SEI) formation, the insertion of the Li ion into the Si and improve the conductivity of the anode.
In order to decorate Si NPs surface with organic ligands, octyne, perfluorooctyne and triethoxy(octyl)silan are used. The resulting materials are fully characterized by electrochemical measurements. In general, we have found that the octyne treatment doesn’t affect the electrochemical properties. Moreover, since the fluoro-organic layer on the Si NPs changes the connection to the SEI, the Perfluorooctyne treatment has decreased the capacity and cycle ability of the Si anode due to the formation of wide cracks on the anode.
.

Figure: from right to left, Si NPs after perflorooctyne, octyne and triethoxy(octyl)silan treatment.

 

[112] INORGANIC CSPBBR3 PEROVSKITE TYPE SOLAR CELL PHOTOVOLTAGE CHARACTERIZATION

 

Jiangang Hu1, laxman gouda1, Ronen Gottesman1, Adi Kama1, Adam Ginsburg2, David A Keller3, Shay Tirosh1, Eli Rosh Hodesh4, Yaniv Bouhadana4, Arie Zaban1

1 Bar Ilan University; Bar Ilan University
2 Bar-Ilan University; Anna&max Webb
3 Bar-Ilan University; Bar-Ilan University
4 Dept. Chemistry; Nanotechnology

Abstract: Hybrid organic-inorganic metal halide perovskites have drew much attention over the past 5 years due to their amazing optoelectronic properties and promising application in energy field. However, compared to hybrid organic−inorganic perovskites, the all-inorganic metal halide perovskites are less studied in the field of solar cells. The inorganic CsPbBr3 perovskite was implemented in solar cell and working as good as its organic counterparts especially in generation of phtovoltage. Here, we have fabricated inorganic CsPbBr3 perovskite type solar cell by sequential deposition method. The photovoltage behavior was studied as a function of light intensity and transient photovoltage decay measurements in both mesoporous and planar structured devices. We discussed the recombination pathway from TiO2 and CsPbBr3 perovskite interface and the long carrier life time due to slow recombination in mesoporous structured device. However, planar structured device showing shorter carrier life time or fast recombination of carriers which may happens in perovskite.

 

[115] RECENT ADVANCES IN THE PRODUCTION OF BIOETHANOL – A RENEWABLE AND ALTERNATE FUEL

 

Indra Neel Pulidindi1, Aharon Gedanken1

1 Bar-Ilan University; Department of Chemistry

Recent Advances in the Production of Bioethanol – a Renewable and Alternate Fuel
Indra Neel Pulidindia & Aharon Gedankena,b
aDepartment of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel
bNational Cheng Kung University, Department of Materials Science and Engineering, Tainan 70101, Taiwan
Tel: +972-3-5318315; Fax: +972-3-7384053;
*E-mail: gedanken@mail.biu.ac.il

Innovative strategies were developed recently for the exploitation of biomass for biofuels production. The concept of biomass itself is being understood in an unconventional sense. Biofuel production strategies are also undergoing drastic changes like the use of solar radiation and microwave irradiation, to meet the fuel demand and to make the process more energy and atom efficient and sustainable.
With the above scientific and technological research background, we have focused on making advances in the first (corn and sugar cane), second (cellulose) and third (algae) generation bioethanol production. First generation bioethanol has already reached the level of commercialization but facing the problem of food Vs fuel conflict. To make this process more profitable we have developed a solar energy driven reactor for the simultaneous saccharification and fermentation (SSF) of starch to bioethanol and demonstrated its applicability in driving fuel cells for electricity generation. Similarly, in the field of second generation bioethanol production, effective utilization of all the components of biomass, especially xylose metabolism is a challenge. We demonstrated the feasibility of xylose metabolism, produced from the hydrolysis of pinus radiata cones, by saccharomyces cerevisiae. With respect to the third generation bioethanol production, we have cocultured the marine algae ulva rigida under nutrient rich conditions where fish were fed, so as to produce carbohydrate rich algae. Subsequently, we have developed a sonication assisted SSF process for the conversion of the high carbohydrate ulva rigida (32 wt. % starch) to bioethanol in high yield (16 wt.% on dry weight basis). All these developments would be discussed in the Nano Israel 2016.

 

[118] ENHANCING DEVICE PERFORMANCE: PLASMONIC NANO-ANTENNAS FOR LIGHT EMISSION, DETECTION AND HARVESTING.

 

Ofir Sorias1

1 Technion; Electrical Engineering

Enhancing Device Performance: Plasmonic Nano-Antennas for Light Emission, Detection and Harvesting
Ofir Sorias* and Meir Orenstein.
Department of Electrical Engineering, Technion – Israel Institute of Technology, 32000 Haifa, Israel.
sorias@tx.technion.ac.il
Abstract: We experimentally demonstrate performance enhancement in detectors, solar-cells and light-emitting diodes, by utilizing plasmonic nanostructures and their localized surface plasmon resonances. We derive design rules for such plasmonic nanostructures – and plasmonic nano-antennas in particular – by investigating their plasmonic properties, and their effects on the emission and absorption capabilities of neighboring materials.
Plasmonic nano antennas (PNA) have been thoroughly investigated in recent years, since their localized surface plasmon resonances (LSPR) enables high field concentration and enhancement. LSPR can increase the local density of photonic states and therefore affect light-matter interactions.
Here we experimentally demonstrate how, with proper design, LSPR can modify absorption and emission processes, and enable new and interesting transitions by manipulating light-matter interactions – thereby achieving better device performance.

Figure 1 shows scanning electron microscope images of several PNAs (a), alongside measured reflection as a function of wavelength (b,c) for two such antennas (red arrows). They exhibit a LSPR accompanied by a corresponding field enhancement (inset, simulated).

Figure 2 shows various plasmonic nanostructure designs enhancing measured performance in three types of devices: a detector with improved responsivity (a), a solar-cell with better efficiency (b), and a light emitting diode with faster modulation times and improved light extraction (c).

[1] A. Pesach, S. Sakr, E. Giraud, O. Sorias, L. Gal, M. Tchernycheva, M. Orenstein, N. Grandjean, F. H. Julien, and G. Bahir, First demonstration of plasmonic GaN quantum cascade detectors with enhanced efficiency at normal incidence, Optics Express 22, 21069 (2014).
[2] T. Segal-Peretz, O. Sorias, M. Moshonov, I. Deckman, M. Orenstein, G. L. Frey, Plasmonic nanoparticle incorporation into inverted hybrid organic–inorganic solar cells, Organic Electronics 23, 144 (2015).

 

[137] HIGH POWER CONVERSION EFFICIENCY OF FTO|TIO2|CUXO|AU SOLAR CELLS

 

Zhi Yan1, Jiangang Hu2, Adam Ginsburg3, Shay Tirosh1, Kevin Rietwyk1, Koushik Majhi4, Assaf Anderson1, Arie Zaban1

1 Bar Ilan University; Bar Ilan University
2 Chemistry Department; Chemistry Department
3 Bar-Ilan University; Anna&max Webb
4 Bar Ilan Institute of Nanotechnology and Advanced Materials (Bina); Bar-Ilan

High power conversion efficiency of FTO|TiO2|CuxO|Au solar cells

Abstract: Cu-O layer, as an absorber, has been researched in many photovoltaic applications, due to its tunable bandgap from 1.4 to 2.1 eV. Although there are reports in the literature on its power conversion efficiency using heterojunctions of Cu2O and ZnO or Ga2O3, these employ an opaque substrate of Cu sheet or Si wafer and which limits possible device architectures, at a higher device cost. Here we use an inexpensive transparent substrate of glass coated with FTO and deposit a TiO2 layer using spray pyrolysis, followed by an electrochemical CuxO deposition – each of the materials and processing steps are low cost and can readily be up-scaled for module fabrication. Detailed characterization on our cells reveal a high power conversion efficiency above 1% with a high short circuit current density of 5 mA/cm2, open circuit voltage of 500 mV and fill factor of 40%.

 

[164] DESIGNING EFFICIENT BIMETALLIC PHOTOCATALYSTS FOR HYDROGEN PRODUCTION

 

eran aronovitch1, Philip Kalisman2, Shai Mangel3, Lothar Houben4, Lilac Amirav5, Maya Bar Sadan6

1 Chemistry Department, Ben Gurion University of the Negev, Beer Sheba, Israel; Chemistry Department, Ben Gurion University of the Negev, Beer Sheba, Israel
2 Technion – Israel Institute of Technology; Technion – Israel Institute of Technology
3 Ben Gurion University; Ben Gurion University
4 Weizmann Institute of Science; Weizmann Institute of Science
5 Technion – Israel Institute of Technology ; Technion – Israel Institute of Technology
6 Ben Gurion University ; Ben Gurion University

Designing efficient bimetallic photocatalysts for hydrogen
production
Eran Aronovitch1, Philip Kalisman2, Shai Mangel1, Lothar Houben3, Lilac Amirav2, Maya Bar-Sadan1*
1 Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, Israel
2 Schulich Faculty of Chemistry, The Russell Berrie Nanotechnology Institute, and The Nancy and Stephen Grand Technion Energy Program; Technion − Israel Institute of Technology, Haifa 32000, Israel
3 Peter Grünberg Institut 5 and Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.

The search for alternative clean and renewable energy source is a major pressing issue. One promising direction is the use of semiconductor nanoparticles as photocatalysts which absorb the solar radiation and produce hydrogen from water. Efficient photocatalysts should maintain charge separation of the holes and electrons and contain different sites for oxidation and reduction. Usually metallic particles are deposited on the semiconductors which acts as electron sinks and a reduction sites for protons.

Hybrid core-shell structures such as CdS@CdSe increase the charge separation and reduce the particle dissolution by confining the holes to the core and leaving the electrons delocalized over the entire structure. A bi-metallic co-catalyst composed of metals such as gold and palladium should improve the photocatalytic activity of the system. Such bimetallic particles possess the ability to attract electrons from the semiconductor and discharge them into the aqueous solution more efficiently then each of the metals separately. Here we use the CdSe@CdS-Au\Pd system as a case study to explore the effect of the inner structure of the bimetallic tip on the photocatalytic performance. In addition we study the dynamic processes which occur during photocatalysis. For this aim we used high resolution energy dispersive spectroscopy (EDS) for the system characterization and an online GC equipped setup for the long duration photocatalytic hydrogen evolution measurements.
*Aronovitch, E.; Kalisman, P.; Mangel, S.; Houben, L.; Amirav, L.; Bar-Sadan*, M.; Designing Bimetallic Co-catalysts: A Party of Two. J. Phys. Chem. Lett. 6, 3760 (2015)

 

[196] TISSUE-LIKE SILICON NANOWIRES-BASED 3D ANODES FOR HIGH-CAPACITY LITHIUM ION BATTERIES

 

Emanuel Peled1, Fernando Patolsky1, Diana Golodnitsky2, Kathrin Freeedman1, Guy Davidi1, dan Schneier1

1 School of Chemistry; School of Chemistry
2 Honeycomb Batteries Ltd; Tel Aviv University

Tissue-like Silicon Nanowires-based 3D Anodes for High-Capacity Lithium Ion Batteries

Emanuel Peled1, Fernando Patolsky1, Diana Golodnitsky1, 2, Kathrin Freedman1, Guy Davidi1, Dan Schneier1

1. School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
2. Applied Materials Research Center, Tel Aviv University, Tel Aviv, 69978, Israel.

Abstract

We report on the scalable synthesis and characterization of novel architecture three-dimensional high-capacity amorphous SiNWs-based anodes, with focus on studying their electrochemical degradation mechanisms. We achieved an unprecedented combination of remarkable performance characteristics, high loadings of 3-25 mAh/cm2, a very low irreversible capacity (10% for the 3-4 mAh/cm2 anodes), current efficiency greater than 99.5%, cycle stability both in half cells and a LiFePO4 battery and fast charge–discharge rates (up to 2.7C at 20mA/cm2). These SiNWs-based binder-free 3D anodes have been cycled for over 500 cycles, exhibiting a stable cycle life. Notably, it was found that the growth of the continuous SEI layer thickness, and its concomitant increase in resistivity, represents the major reason for the observed capacity loss of the SiNWs-based anodes, as we demonstrate by cleaning and reusing cycled anodes. We have recently begun experimenting with different types of coatings to further improve SEI and cycling stability. Our data reveal that NWs-based anodes of novel architecture are expected to meet the requirements of lithium-ion batteries for both portable and electric-vehicle applications.

 

[204] LIMITING NON RADIATIVE PATHWAYS IN ORGANIC-­INORGANIC PEROVSKITE SOLAR CELLS USING A P3HT NANOWIRES–PMMA BLEND AS AN EFFICIENT AND CHEAP HOLE‐TRANSPORTER

 

Alba PELLAROQUE1

1 University of Oxford; University of Oxford

From a stability point of view, an ideal Hole Transporter Material (HTM) would protect the perovskite from ambient moisture while still ensuring effective charge transfer and transport. Moreover, to achieve a perfect solar cell, the desired contact must not induced any nonradiative decay channels at open circuit conditions, maximizing the attainable photovoltage. In the case of the perovskites solar cells, all contacts used induce a non-radiative decay channel across the contact-semiconductor interface. Holes in the HTM recombine with electrons in perovskite, explaining the extreme photoluminescence quenching thus far always observed at perovskites – HTM interfaces. Hence, the ideal HTM is one that can perform the multiple tasks of being hole-selective, protecting the semiconductor from ambient conditions, without impeding but perhaps even improves radiative recombination yields in the semiconductor – HTM composite.
We developed a dopant free hole-transporter composite by blending P3HT nanowires semiconducting polymer with insulating PMMA. Such blend shows high increase in open circuit voltage suggesting a drastic reduction of non-radiative recombination decay channels, as well as improves stabilized efficiency compared to the pristine P3HT. Interestingly, the PMMA/P3HT-NWs composite hole-conductor seems to operate through a very different mechanism than any other currently known HTMs. We propose that upon light excitation, holes are rapidly transferred from the absorber to the nanowires, where they reside with long lifetimes and then transfer back to the valence band of the perovskite. Then, holes recombine radiatively leading to a large enhancement in photoluminescence yield.

 

[206] NOVEL EXOHEDRAL NANOCARBON HYBRID STRUCTURE: CARBON NANOTUBE COATED BY FULLERENE SHELL

 

Eugene Katz1

1 Ben-Gurion University of the Negev; J. Blaustein Institute for Desert Research

Novel Exohedral Nanocarbon Hybrid Structure: Carbon Nanotube Coated by Fullerene Shell
Leonid A. Chernozatonskii,a Anastasiya A. Artyukh,a Victor A. Demin,a
Eugene A. Katzb,c,*
a. Emanuel Institute of Biochemical Physics, RA S, Moscow,119334 Russia
b. Dept. of Solar Energy and Environmental Physics, The Jacob Blaustein Institutes for Desert Research (BIDR), Ben-Gurion University of the Negev, Sede Boker Campus 84990, Israel
c. Ilse Katz Institute for Nanoscale Science & Technology, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
* Corresponding author, e-mail: keugene@bgu.ac.il

Can a C60 layer cover a surface of single-wall carbon nanotube (SWCNT) forming an exohedral pure-carbon hybrid with only van der Waals (VdW) interactions? The aim of the present work is to address this question and to demonstrate that the fullerene shell layer in such a bucky-corn structure can be stable. Theoretical study of the structure, stability and electronic properties of bucky-corn hybrids is reported for the shell of C60 and C70 molecules on an individual SWCNT, C60 dimers on an individual SWCNT, as well as C60 molecules on SWNT bundles. The geometry and total energies of the bucky-corns were calculated by the molecular dynamics method while the density functional theory method was used to simulate the electronic band structures [1].

References
1. L. A. Chernozatonskii, A. A. Artyukh, V. A. Demin and E. A. Katz, Molecular Physics (2015), in press. DOI: 10.1080/00268976.2015.1086834.

 

[236] HYBRID CDS-AU NANORODS AS PHOTOCATALYSTS; SURFACE COATING AND METAL DOMAIN SIZE EFFECTS.

 

Yuval Ben Shahar1

1 The Institute of Chemistry and Center for Nanoscience and Nanotechnology; The Hebrew University of Jerusalem

Water reduction for hydrogen production by semiconductor-metal hybrid nanoparticles (HNPs) has been considered a promising approach towards renewable solar energy harvesting in form of chemical energy stored in a hydrogen fuel. The synergistic optical and chemical properties of HNPs such as light-induced charge separation and charge transfer, allow photocatalytic activity which can promote surface chemistry redox reactions. Control over components materials, shape, size and surface coating permits fine tuning of wavelength absorption range, energy band alignment and surface traps suppression which are key-factors for efficient charge transfer and overall catalysts activity.

Here we report on the effects of the surface coating and the co-catalyst metal size on the photocatalytic function of Au tipped CdS nanorods as a model hybrid nanoparticle system. Both tested parameters were found to influence the photocatalytic efficiency and charge transfer dynamics. Different types of surface coatings including various types of thiolated alkyl ligands and different polymer coatings were explored. A significant increase in the apparent quantum yield was detected for polyethylenimine (PEI) coated NPs compared to other surface coatings, such as L-Glutathione and mercaptoundecanoic acid. This pronounced increase in the photocatalytic efficiency is attributed to the improved surface passivation by the PEI polymer reducing the surface trapping of charge carriers, compared to alternative surface coatings. Investigation of different sizes of Au metal component reveal an optimum behavior in which an intermediate size of metal domain provides the optimal hydrogen evolution rate for the photocatalytic water reduction while smaller sized Au tips show slower rates and lower efficiency and larger sizes expose also lower rates and reduced apparent quantum yield. Ultrafast transient absorbance measurements in collaboration with Cerullo’s Group from POLMI along with steady-state emission and time-resolved spectral measurements support these observations. The understanding of the effect of the hybrid nanosystems properties on the photocatalytic processes contributes to the great potential of hybrid nanostructures photocatalytic applications.

 

[263] IMPACT OF ANTI-SOLVENT TREATMENT ON CARRIER DENSITY IN EFFICIENT HOLE CONDUCTOR FREE PEROVSKITE BASED SOLAR CELLS

 

Bat-El Cohen1

1 The Hebrew University of Jerusalem; The Hebrew University of Jerusalem

Impact of anti-solvent treatment on carrier density in efficient hole conductor free perovskite based solar cells
Bat-El Cohen, Sigalit Elboher, Alex Dymshits, Lioz Etgar*
The Hebrew University of Jerusalem, Jerusalem 919040, Israel

Recently organic-inorganic perovskite has attracted lot of attention due to its properties, which are suited to photovoltaic (PV) solar cells. The efficiency of perovskite-based solar cells has increased in a short time, achieving today 20.1% [1]. It was demonstrated that the perovskite could function simultaneously as light harvester and hole conductor, simplifying the solar cell structure and potentially reducing its cost. This work demonstrates anti-solvent treatment of organo-metal halide perovskite film. We found that the anti-solvent (toluene) surface treatment affects the morphology of the perovskite layer, and importantly it also affects the electronic properties of the perovskite. One of the most discussed phenomena in the field of perovskite-based solar cells is the hysteresis effect. It has been demonstrated that hysteresis is present in the perovskite solar cells, and hysteresis is heavily dependent on the solar cell structure as well as on the scan velocity during current voltage (IV) measurements [2]. Conductive atomic force microscopy (cAFM) and surface photovoltage show that the perovskite film becomes more conductive after the antisolvent treatment. Moreover, the anti-solvent treatment suppresses the hysteresis commonly obtained for perovskite-based solar cells. When characterizing the perovskite only, an IV plot of a single perovskite grain measured by cAFM shows that the hysteresis vanishes after the toluene treatment.
We postulated that during the toluene treatment, the excess of charges on the perovskite surface is removed, leading to a stable and naturalized perovskite crystal. As a result of the anti-solvent surface treatment, a hole conductor free, perovskite-based solar cell demonstrates impressive power conversion efficiency of 11.2%.

References
[1] http://www.nrel.gov/ncpv/images/efficiency_chart.jpg.
[2] Snaith, H. J. et al. J. Phys. Che. Lett., 2014, 5, 1511−1515.

 

[275] INORGANIC LAYERED MATERIALS AS CHARGE TRANSPORT LAYERS IN LEAD HALIDE BASED PEROVSKITE SOLAR CELLS

 

Peter Topolovšek1, Francesco Lamberti1, Chen Tao1, Victor Vega Mayoral2, Matej Prijatelj2, Christoph Gadermaier2, Annamaria Petrozza1

1 Center for Nanoscience and Technology, Istituto Italiano DI Tecnologia; Via Pascoli 70/3
2 Jožef Stefan Institute; Jamova Cesta 39

The performance leap of hybrid organic-inorganic perovskite solar cells can be ascribed to many factors, for example smart processing and deposition techniques, research on alternative metal halide compounds and the advancement in the synthesis of charge transport materials. However, the use of charge transport materials is often limited to organic polymers and small molecules which are commonly dissolved in chlorinated solvents that are not considered environmentally friendly. Recently it has been shown that the use of their inorganic counterparts show better solar cell stability over time, but it still requires high temperature deposition processing1. In this work we examine the charge transfer interface between exfoliated semiconducting inorganic layered materials, such as MoS2 and WS2, and methylammonium lead halide perovskites. The advantages of presented layered materials originate from their simple and scalable exfoliation methods2, ease of processing and doping techniques3, as well as the ability to deposit them in a form of ultra thin films which conform to the active layer surface4. In terms of device construction this results in scalable deposition and, due to the quasi 2D nature of materials, in significant reduction of material consumption. In addition, we use doping in solution to tune the properties of layered materials affecting the series resistance of the device and have control over the band alignment between the active and charge selective layer.

References:
1. W. Chen, et al. Efficient and stable large-area perovskite solar cells with inorganic charge extraction layers. Science, 29 October 2015 (10.1126/science.aad1015)
2. R. J. Smith, et al. Large-scale Exfoliation of Inorganic Layered Compounds in Aqueous Surfactant Solutions. Adv. Mater. 23, 3944–3948 (2011).
3. Y. Shi. et al. Selective Decoration of Au Nanoparticles on Monolayer MoS2 Single Crystal. Sci. Rep. 3, 1839 (2013).
4. X. Yu, M.S. Prévot, N. Guijarro and K. Sivula. Self-assembled 2D WSe2 thin films for photoelectrochemical hydrogen production. Nat. Comm. 6, 7596 (2015).

 

[295] DEVELOPMENT OF ORGANIC MATERIALS FOR PEROVSKITE SOLAR CELLS

 

Jeroen van der Velden1

1 Via Morego 30, 16163; Via Morego 30, 16163

Abstract: Perovskite solar cells are a promising class of solar cells due its low-cost solution processing and high power-conversion efficiencies close to 20% approach that of crystalline Si solar cells at lab scale. In such scenario their low long-term stability represent a crucial issue to get to the market.
Here we address such issue both working on the active material and on the device architecture where it is embodied.
The standard device architecture for Perovskite solar cells, also known as the direct architecture is TCO/TiO2/Perovskite/HTM/Au. In this architecture TiO2 works as an electron-extracting layer but is instable upon UV exposure, which can have a detrimental effect on long-term stability. To avoid this issue, the inverted architecture could be used with TCO/PEDOT: PSS/Perovskite/PCBM. The drawback of this architecture is the long-term stability and parasitic absorption of PEDOT: PSS.
An alternative approach is to use PCBM in a direct architecture as an electron-extracting layer. Due to the solubility of PCBM in DMF the perovskite layer has to be deposited in 2 steps by evaporation of PbI2 and spin coating of methylammonium iodide. To avoid the problem of solubility, cross-linkable C61-fullerene derivative was synthesized which can be cross-linked by heating, and could be a good candidate to make it possible to prepare solution process able devices with C61-fullerene derivatives.
On the surface of the active material (perovskite), different kinds of defect sites are present with energy levels close to the conduction band edge. These defect sites (such as under-coordinated Pb atoms) might lead to trap sites, which have a negative influence on the device efficiency and the mobility of defects seems to be emerging as the primary cause of electrical instability often observed in these solar cells. To fill up these defect sites we have designed different kinds of passivation materials for the surface treatment of the perovskite. By successful treatment of defect sites we expect an increase in PCE and long-term stability.

 

[309] ROLE OF EXTRACTING [6,6]-PHENYL-C61-BUTYRIC ACID METHYL ESTER (PCBM) INTERLAYER IN PEROVSKITE SOLAR CELLS IN THE LIGHT OF MOVING IONS

 

Vijay Venugopalan1, Annamaria Petrozza2, Francesco Lamberti2, Chen Tao2

1 Center for Nanoscience and Technology,; Istituto Italiano DI Tecnologia
2 Center for Nanoscience and Technology, Istituto Italiano DI Tecnologia; Via Pascoli 70/3

Abstract: In the last few years hybrid organic-inorganic metal halide perovskites have proven to be genuine challengers for traditional technologies in the field of solar cells and display technologies. Such rapid growth in efficiencies of solar cells has been unprecedented for any generation of solar technology. One of the major challenges facing us is to tackle the problem of stability in these solar cells, the origins of which are presently poorly understood. One school of thought points towards ionic motion in these semiconductors to be the key factor. Presently the mechanism of ionic motion in these cells and their effect on neighboring charge extracting layers is poorly understood. Herein we take a closer look at the interaction between the moving iodine(I-) ions in perovskites and the [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) interlayer that are widely used in perovskite solar cells. We also observe permanent changes with light soaking in both types of cell. Through Electrochemical Impedance Spectroscopy (EIS) we observe that cells with PCBM interlayers show larger capacitances after light soaking over all relevant frequency ranges. This is in contrast with devices lacking PCBM interlayers where the overall impedance drastically reduces after light soaking. The reverse bias Schottky rectification also improves with light soaking for cells with the PCBM interlayers and weakens for cells without PCBM, pointing towards a permanent change to the interface due to PCBM. In conclusion, we propose that the interaction of the moving I- ions with the PCBM permanently change the electron extraction interface of solar cells, which may be one of the chief responsible factors responsible for the stabilized efficiency and smaller hysteresis observed in these cells.

 

[313] INVERTED AND STANDARD ARCHITECTURE PEROVSKITE SOLAR CELLS: IMPACT OF NIO AND TIO2 BLOCKING LAYERS DEPOSITION TECHNIQUE

 

Ralf Niemann1

1 University of Bath; Claverton Down

ABSTRACT:
Methylammonium lead halide perovskites (CH3NH3PbX3; X = Cl, Br, I) are hybrid organic-inorganic materials with a perovskite crystal structure and are a promising candidate in next-generation solar cells. After their first employment in photovoltaics in 2009 with an efficiency of 3.9 % (Kojima et al.) they experienced a fast increase to a certified efficiency of currently to over 20 % (NREL).
In this work we analyze the impact of different types of blocking layers on the operation and performance of perovskite solar cells. Classical perovskite cells were fabricated based on an n-type TiO2 electron blocking layer and were compared to organic n-type layers. Because the processing can influence the work function of the resulting blocking layer we employed three different deposition techniques of TiO2 and compared their function as an efficient electron extraction layer. On the other hand, perovskite solar cells with an inverted structure were fabricated, where the bottom layer was based on a p-type NiO layer. Again, three different deposition techniques of NiO were used and results were compared to organic p-type layers. The measured IV curves were compared to a drift-diffusion model for charge carriers, which gives insight into the solar cells operating mechanism.
Our study gives a detailed account of organic and inorganic blocking layer fabrication methods and their influence on the operational mechanism of perovskite solar cells. We hope that these findings help in the production of more efficient cells and aid a better understanding of the physics at the blocking layer-perovskite interface.

 

[360] PERFORMANCE OF SILICON NEGATIVE ELECTRODES WITH CNTS IN LI-ION SYSTEMS

 

Sivan Okashy1

1 Bar Ilan Univesity; Bar Ilan Univesity

Performance of silicon negative electrodes with CNTs in Li-ion systems
Sivan Okashy, Shalom Luski and Doron Aurbach
Department of chemistry, Bar Ilan University. Ramat-Gan 52900 Israel.
Silicon is capable of delivering a high theoretical specific capacity of 4200 mAh g-1 order of magnitude higher than that of the state-of-the-art graphite based negative electrodes for lithium-ion batteries. Using silicon- containing negative electrodes can increase significantly the energy density of the Li – -ion cell. However, the poor cycle life of silicon electrodes, caused by the large volumetric strain during cycling, limits the commercialization of silicon electrodes. As one of the essential components, the polymeric binder is critical to the performance and durability of lithium-ion batteries as it keeps the integrity of electrodes, maintains conductive path and must be stable in the electrolyte. When addressing micrometric Silicon the conductivity must be taken under consideration and can be compensated by conductive additives such as CNTs. In this work, we demonstrate that electrodes consisting of silicon micrometric mixed with commercially available sodium alginate as well as CNTs are able to maintain a high specific capacity over 1500 mAh g-1 150 cycled between 0.7 V and 0.05 V.

 

[369] INFLUENCE OF TIO2 PHOTOELECTRODE STRUCTURE IN QUANTUM DOT SOLAR CELLS PERFORMANCE

 

Lida Givalou1, Maria Antoniadou1, Maria Giannouri1, Athanassios Kontos1, Polycarpos Falaras1

1 National Center for Scientific Research Demokritos; Institute of Nanoscience and Nanotechnology

Influence of TiO2 Photoelectrode Structure in Quantum Dot Solar Cells Performance

Lida Givalou, Maria Antoniadou, Maria Giannouri, Athanassios G. Kontos, Polycarpos Falaras*

Institute of Nanoscience & Nanotechnology, NCSR Demokritos, 15310 Agia Paraskevi, Attiki, Greece
* Corresponding author: p.falaras@inn.demokritos.gr

Quantum dots are used as low cost photosensitizers in order to replace the organic dyes and the transition metal complexes in dye sensitized solar cells. The main advantages of using quantum dots lay on the ability to tune the bandgap according to their particle size and the high molar extinction coefficients of the materials which permit the generation of high photocurrent density values. This particular behavior is due to its small particle size which is comparable to the de Broglie wavelength of the nanocrystalline semiconductor electrons. In this context, the use of quantum dots as photosensitizers, contributes to the preparation of efficient solar cells, which are known as Quantum Dot Sensitized Solar Cells (QDSSCs).
In this work, core/shell CdS-ZnS/CdSe QDs have been employed to assemble QDSSCs. The TiO2 photoanode structure has been optimized using several treatments including TiCl4, sol-gel compact layer, transparent layer and scattering layer approaches. The influence of the TiO2 film thickness on the cell performance has been examined as well. In addition, the porosity of the transparent layer has been controlled by modifying the ethyl cellulose concentration in the paste. The experimental results show that TiCl4 treatment increases the Jsc values but does not particularly improve the cell performance. Sol-gel works marginally better than TiCl4 as compact layer. The thickness increase for both the mesoporous film and the scattering layer improves the cell performance. Following a careful control on the balance between the scattering and mesoporous layer, the optimized CdSe /CdS-ZnS/ TiO2 QDSSCs demonstrated energy conversion efficiency (η) as high as 6.50% under one sun illumination (AM 1.5G, 100 mW cm− 2), which is among the highest values reported in the literature.

 

[388] CONTROLLING THE REACTIVITY OF ANATASE “CORES” USING COVALENTLY ATTACHED REDOX-ACTIVE INORGANIC PROTECTING LIGANDS

 

Manoj Raula1, Gal Gan Or2, Marina Sa2, Ira Weinstock2

1 Department of Chemistry and ; Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of Negev, Israel
2 Ilse Katz Institute for Nanoscale Science & Technology; Ben-Gurion University of Negev

Controlling the reactivity of anatase “cores” using covalently attached redox-active inorganic protecting ligands
Manoj Raula, Gal Gan-Or, Marina Saganovich and Ira A. Weinstock
Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of Negev, Israel

An unprecedented role for metal-oxide cluster-anions (polyoxometalates, or POMs) as covalently coordinated inorganic ligands for individual anatase nanocrystals, giving isolable anionic clusters uniquely positioned between molecular macroanions and traditional colloidal nanoparticles. Water-soluble polyanionic structures are obtained by reacting amorphous TiO2(s) with the 1-nm size mono-defect Keggin ion, Na(8-n)[α-Xn+W11O39], Xn+ = P5+, at 170 C, after which, an average of 55 ± 10 α-PW11O397- anions are found as pentadentate “capping” ligands for complexed Ti(IV) ions still linked—via their sixth coordination site—to 6-nm single-crystal anatase-TiO2 cores. Multiple lines of evidence reveal that the POM-protecting ligands are covalently bound to the surface of anatase nanocrystals, giving clear solutions over a wide range of pH values, and allowing for repeated precipitated and re-dissolution in water. EDS and XPS data suggest that numerous POMs are associated with each 6-nm anatase nanocrystal, and high-resolution TEM, cryogenic-TEM, and HAADF-STEM images clearly show POM-protecting ligands bound to anatase surfaces. Solid-state NMR and ESI-MS mass spectra unambiguously identify the covalently bound POM-protecting ligands as TiPW11O405–derived clusters. The surface-bound cluster-anions are reversible electron acceptors, whose reduction potentials shift to more negative values by simply changing the central heteroatom, Xn+, from P5+ to Si4+ to Al3+. Hence, just as POM cluster-anions control the reactivities of metal centers in molecular complexes, directly coordinated POM ligands with tunable redox potentials provide better control over the reactivity of TiO2 nanocrystal cores. This rational tuning of metal-oxide nanocrystal reactivity is demonstrated using photochemical hydrogen evolution from water.1

(1) Manoj Raula, Gal Gan Or, Marina Saganovich, Offer Zeiri, Yifeng Wang, Michele R. Chierotti, Roberto Gobetto, and Ira A. Weinstock, Angew. Chem. Int. Ed., 2015, 54, 12416-12421.(Highlighted as a Hot Paper)

 

[393] A NOVEL MESO/PLANAR HYBRID ARCHITECTURE OF METHYLAMMONIUM LEAD IODIDE BASED PEROVSKITE SOLAR CELLS

 

Ravi K Misra1, Bat-El Cohen2, Michael Layani3, Shlomo Magdassi4, Lioz Etgar5

1 Hebrew University of Jerusalem, Israel; Hebrew University of Jerusalem, Israel
2 The Hebrew University of Jerusalem; The Hebrew University of Jerusalem
3 Casali Institute for Applied Chemistry; Institute of Chemistry
4 Casali Center of Applied Chemistry; The Hebrew University of Jerusalem
5 Casali Institute of Applied Chemistry, Hebrew University of Jerusalem; Hebrew University of Jerusalem, Israel

A novel meso/planar hybrid architecture of methylammonium lead iodide based perovskite solar cells
Ravi K. Misra, Bat-El Cohen, Michael Layani, Shlomo Magdassi & Lioz Etgar
Casali Center for Applied Chemistry, Hebrew University of Jerusalem, Givat Ram Campus, Jerusalem, Israel-91904
Perovskite based solar cells have seen tremendous development in last five years and recently achieved a record efficiency of 20.1 %1. The high efficiency cells from the group usually based on meso-TiO2 as a base layer for perovskite infiltration, though the exact role of TiO2 in these cells is yet to be explained.
Here we are reporting for the first time a novel architecture of perovskite based solar cells, which, we prefer to call meso/planar hybrid architecture of perovskite solar cells. The deposition of meso-TiO2 after compact TiO2 blocking layer, has been done with the help of a grid in these cells similar to already reported by our group for the development of semitransparent solar cells2, followed by methyl ammonium lead iodide perovskite deposition using two step deposition process.
The initial results found promising with power conversion efficiency (PCE) of 7.9% with high open circuit voltage and reasonable current density of about 14 mA/cm2. The cells are supposed to be a good architecture to study the effect of interfaces on the cell performance using Impedance spectroscopy, since they have the compact-TiO2/perovskite (planar) interface on one hand, meso-TiO2/perovskite (meso) interface on the other hand. The detailed studies of this novel architecture, including their photovoltaic performance and effect of structural modifications on the cells PV properties will be the part of presentation.

Keywords: meso/planar hybrid architecture, perovskite solar cells, TiO2 grid, Methylammonium lead iodide perovskite

References:
1. http://www.nrel.gov/ncpv/images/effi ciency_chart.jpg. Accessed: March 2015.
2. Sigalit Aharon , Michael Layani , Bat-El Cohen , Efrat Shukrun , Shlomo Magdassi and Lioz Etgar, Self-Assembly of Perovskite for Fabrication of Semitransparent Perovskite Solar Cells, Adv. Mater. Interfaces 2015, 1500118.

 

[409] GA MODIFIED ZEOLITE BASED SOLID ACID CATALYST FOR LEVULENIC ACID PRODUCTION

 

Vijay Bhooshan Kumar1

1 Bar Ilan Institute for Nanotechnology and Advanced Materials; Bina, Department of Chemistry, Bar Ilan University

Ga modified zeolite based solid acid catalyst for levulenic acid production
Vijay Bhooshan Kumara, Indra Neel Pulidindia, and Aharon Gedankena, b*
aDepartment of Chemistry and Bar-Ilan Institute for Nanotechnology & Advanced Materials, Bar Ilan University, Ramat-Gan 52900, Israel
bNational Cheng Kung University, Department of Materials Science & Engineering, Tainan 70101, Taiwan
*Corresponding author email: gedanken@mail.biu.ac.il
Fax: 972-3-7384053; Tel: 972-3-5318315

ABSTRACT:
Gallium modified zeolite (mordenite) solid acid catalyst using the sonochemical method. The catalyst (Ga@Zeolite) was characterized using XRD, SEM, TEM, EDS, FTIR, DSC, and TGA analysis. It was found that Ga was inserted in the pores of zeolites. In addition, small Ga particles (5-60 nm) were found in between the zeolite crystals. The catalyst was further used for the production of levulinic acid from carbohydrates (glucose, molassa, sucrose, starch, and cellulose) in a hydrothermal process. Reaction conditions (time, ratio of amount of substrate and catalyst) for the optimum yield of levulinic acid were deduced (175 ˚C and 6 h). The reaction products were analysed qualitatively using NMR (1H and 13C) and quantitatively by HPLC analysis. The maximum yield of levulinic acid obtained from glucose was 60.4 wt. % and efficiency conversion is > 90%..

Keywords: Zeolite, Ga@mordenite, Hydrolysis, Hydrothermal process; Glucose; Levulenic acid

 

[412] HARSH REVERSE BIAS STRESS OF DYE SENSITIZED SOLAR CELLS MONITORED VIA ELECTRICAL AND SPECTROSCOPIC METHODS

 

Harry Georgiou1, Athanassios Kontos2, Antonio Agresti3, Aldo Di Carlo4, Sara Pescetelli5, Polycarpos Falaras2

1 National Centre for Scientific Research Demokritos; Agia Paraskevi
2 National Center for Scientific Research Demokritos; Institute of Nanoscience and Nanotechnology
3 Center for Hybrid and Organic Solar Energy; Chose
4 Dipartimento DI Ingegneria Elettronica and Chose; Tor Vergata
5 Tor Vergata; Center for Hybrid and Organic Solar Energy

HARSH REVERSE BIAS STRESS OF DYE SENSITIZED SOLAR CELLS MONITORED VIA ELECTRICAL AND SPECTROSCOPIC METHODS
Harry Georgioua, Athanassios G. Kontosa, Antonio Agrestib, Sara Pescetellib, Aldo Di Carlob and Polycarpos Falarasa
a Institute of Nanoscience and Nanotechnology, NCSR Demokritos, 15310 Athens, Greece
b C.H.O.S.E. (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome Tor Vergata, via del Politecnico 1, 00133 Rome, Italy

Abstract
Harsh reverse bias has been applied in dye sensitized solar cells (DSCs) forcing a fixed short-circuit current of 250 mA for a duration of 165 hours. This test simulates real stress of shadowed DSCs and results in considerable degradation, about 30%, loss of their solar to electrical conversion efficiency. The degradation of the cells has been characterized by Linear Sweep Voltammetry, UV-VIS absorption spectroscopy and resonant Raman scattering diagnostics. The ageing of the DSCs resulted in increased luminescence background signals and significant changes in the Raman peak intensities with respect to the reference TiO2 peak at 143 cm-1; thus the intensity of the 169 cm-1 mode due to dye-triioidide complexes increases while the corresponding intensities of the triiodide 110 cm-1 and the dye 1543 cm-1 modes decrease. Reduction of the diffusion limiting currents and changes in the transmittance and reflectance signals indicate triiodide losses and justifies decrease of the fill factor, as the main reason for the reduction in efficiency of the DSCs. Curiously, at low irradiation level (0.1 sun) the cells present increased photocurrents and efficiencies after RB stress justified by the increase of the light absorbance by the dye due to the triiodide decrease while, at such low light intensities, the increase of the diffusion resistance has not any decisive role in the operation of the cells.

 

[413] CORE/SHELL SI-NI/C ANODES FOR HIGH-ENERGY-DENSITY LI-ION BATTERIES

 

Keren Goldshtein1, Meital Goor1, Kathrin Freeedman2, dan Schneier2, Diana Golodnitsky3, Emanuel Peled2

1 Tel-Aviv University; Tel-Aviv University
2 School of Chemistry; School of Chemistry
3 Honeycomb Batteries Ltd; Tel Aviv University

Core/Shell Si-Ni/C Anodes for High-Energy-Density Li-Ion Batteries
K. Goldshtein1, M. Goor1, K. Freedman1, Dan Schneier1, D. Golodnitsky1,2, and E. Peled1
1 – School of Chemistry; 2 – Wolfson Applied Materials Research Center,
Tel Aviv University, Tel Aviv, 69978
The goal of this research was the development of low-cost, high-capacity, long-cycle-life and safer anode materials to replace the graphite anode of the common lithium-ion battery. Silicon offers the highest gravimetric capacity as an anode material (e.g. Li22Si5: nearly 4,200mAh/g). However, Si-based electrodes typically suffer from large volume changes (up to 420%) during insertion and extraction of lithium. This is followed by cracking and pulverization of silicon, which in turn, leads to the loss of electrical contact, an unstable SEI and eventual capacity fading.
Our strategy for reducing the deterioration of silicon involve attaching silicon and silicon-nickel nanoparticles to multiwall carbon nanotubes (MWCNT) in order to create a silicon-based active anode material supported by a strong, rigid and high-electrically-conducting network. The method is based on the pyrolysis of the mixture of nanoparticles and nanotubes with carbon precursor. Silicon-nickel alloying is achieved by electroless or grinding process followed by pyrolysis. Nickel was chosen since, when alloyed with silicon, this metal is expected to stabilize the structure of lithiated silicon nanoparticles, increase electron conductivity and possibly induce graphitization of the carbon shell.
Li/SiNi-MWCNT-C (1.6mg/cm2 loading) cells exhibited a de-intercalation capacity of 900mAh/ganode at C/7, 600mAh/ganode at C/3.4 and 400mAh/ganode at C/1.7. Irreversible capacity of 22% and high faradaic efficiency (FE) of 99.5% were obtained. Very highly loaded anodes, weighing 5.5mg/cm2, with de-intercalation capacities of 1000mAh/ganode, demonstrated stable cycle life three times greater than that of graphite.

 

[488] ELECTROCHEMICAL REDUCTION OF CARBON DIOXIDE USING CATALYTIC PORPHYRIN/GRAPHENE SYSTEMS

 

Yair Bochlin1

1 Iki; Ben Gurion University

Electrochemical Reduction of Carbon Dioxide Using Catalytic Porphyrin/Graphene Systems

Yair Bochlin, Eli Korin and Armand Bettelheim
Department of Chemical Engineering, Ben-Gurion University of the Negev
P.O.B. 653, Beer Sheva 8410501
Yairboch@post.bgu.ac.il

The CO2 levels in air have been increasing over the past few decades. The conversion of CO2 back to fuels is a critical goal that would restore balance to the rising CO2 levels. CO2 is a very stable, linear molecule, and returning it to a useful state in the form of fuels is a challenging problem. CO2 reduction is possible through chemical catalysis, electrochemistry, photo-chemistry and biological processes. Chemical catalytic processes generally operate at high temperatures and pressures which lead to high energy cost.
The electrocatalytic capabilities toward CO2 reduction of some cobalt porphyrins have been reported. The present work deals with the spectroscopic and electrochemical examination of the interactions occurring between such porphyrins and graphene derivatives, and their effect on CO2 reduction. Such self-assembled systems formed between 5,10,15,20-Tetrakis(1-methyl-4-pyridinio) porphyrin (CoTMPyP) and graphene carboxyl were deposited on electrode surfaces (such as glassy carbon) by means of adsorption or electrodeposition.
The electrodeposited system showed increased activity for CO2 reduction compared to an inert environment (1.2 mA/cm2 and 0.25 mA/cm2, respectively, at -1.2V vs. Ag/AgCl) as examined in an aqueous 0.1 M Na2CO3 solution at pH 11.5.

 

[491] NANOHETEROSTRUCTURE PHOTOCATALYST DESIGN

 

Sandip Pahari1, Lilac Amirav2

1 Israel Institute of Technology, Technion; Schulich Faculty of Chemistry
2 Schulich Faculty of Chemistry; Technion – Israel Institute of Technology

Nanoheterostructure Photocatalyst Design
Sandip Kumar Pahari, Lilac Amirav
Schulich Faculty of Chemistry, Technion – Israel Institute of Technology
Russell Berrie Nanotechnology Institute, Technion – Israel Institute of Technology
Haifa, 3200008, Israel, Tel: +972-4-829-3715. E-mail: lilac@technion.ac.il

Abstract:
The solar-driven photocatalytic splitting of water into hydrogen and oxygen is a potential source of clean and renewable fuel. Solar-to-fuel energy conversion alleviates the energy storage problem, since fuel can be stored more easily than either electricity or heat. After four decades of global research systems that are sufficiently stable and efficient for practical use have not yet been realized.
The photocatalyst activity is strongly correlated with its structure, morphology and composition. Hence, the design of effective artificial photocatalytic systems depends on our ability to precisely control these parameters. Here we present the design and synthesis of advanced photocatalysts, based on innovative nano scale hybrid particles. Our multi-component nanoheterostructure combines semiconductors (CdSe@CdS) with metal (e.g. Pt and Ni) and metal oxide (e.g. Fe2O3) co-catalysts, in a controlled and variable spatial arrangement. Our design targets improved charge separation, facilitates formation of distinct redox reaction sites, and minimize back reaction of intermediates. In particular we examine utilization of hollow structures for the oxidation half reaction in order to facilitate close proximity of intermediates and assist the forward reaction in this complex multi-step process.

 

[492] ANISOTROPIC PLASMONIC METAL-SEMICONDUCTOR NANOHYBRIDS

 

Firdoz Shaik1, Imanuel Peer2, Lilac Amirav3

1 Russell Berrie Nanotechnology Institute; Technion-Israel Institute of Technoloy
2 Russell Berrie Nanotechnology Institute; Technion – Israel Institute of Technology
3 Schulich Faculty of Chemistry; Technion – Israel Institute of Technology

Anisotropic Plasmonic Metal-Semiconductor Nanohybrids
Firdoz Shaik, Imanuel Peer and Lilac Amirav
Schulich Faculty of Chemistry, Technion – Israel Institute of Technology
Russell Berrie Nanotechnology Institute, Technion – Israel Institute of Technology
Haifa, 3200008, Israel, Tel: +972-4-829-3715. E-mail: lilac@technion.ac.il

Plasmonic nanostructures are known to enhance by orders of magnitude various light-matter interactions. The use of plasmon resonances to manipulate optical processes in semiconductors has been gaining increasing attention. Here we present a synthesis of controlled plasmonic nanostructure/quantum dot (QD) dimers, optimized for maximal field enhancement. We are particularly interested in anisotropic plasmonic metal nanoparticles that exhibit unique optical and electrical properties as compared to spherical plasmonic metal nanoparticles. These heterostructures will serve as model systems for exploring and exploiting plasmon-enhanced photophysical processes.
We report here on the synthesis of Au nanoprism@SiO2@CdSe-QDs nanohybrids. Au nanoprisms were synthesized by using a one-pot seedless method through oxidative etching process. The silica shell, which was deposited on the Au nanoprisms by a sol-gel method, was functionalized with amine groups to which CdSe QDs were connected. The distance between CdSe QDs and Au nanoprisms can be controlled by fine-tuning the thickness of the silica shell. This synthetic strategy can be extended for the synthesis of other complex anisotropic plasmonic metal-semiconductor nanohybrids. We believe these plasmonic/QD nanohybrids can become generalized systems for studying and discovering a range of nano-optic phenomena, and serve as groundwork for the development of several important applications, such as improved solar energy harvesting systems.

 

[505] GRAPHITE/CARBON BLACK NANOCOMPOSITE COUNTER ELECTRODE FOR PEROVSKITE SOLAR CELLS

 

surendra kumar yadav1

1 C.H.O.S.E. (Centre for Hybrid and Organic Solar Energy), Department of Electronics Engineering; Via Polytecnico 1

Graphite/Carbon black nanocomposite counter electrode for perovskite solar cells
Surendra K. Yadav1, , Francisco Fabregat Santiago2, Eva M. Barea2, , Fabio Matteocci1, Juan Bisquert2, Aldo Di Carlo1
1C.H.O.S.E. (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome “Tor Vergata”,via del Politecnico 1, Rome, 00133 Italy.
2Photovoltaics and Optoelectronic Devices Group, Departament de Fisica, Universitat Jaume I, 12071 Castello, Spain.
Email: surendraky@gmail.com
Recently, methylammonium lead halide have invoked remarkable amount of scientific and commercial attention for developing cost-effective, high-efficiency solar cells to meet the ever increasing demand for clean energy. Hole conductors such as the widely used Spiro-OMeTAD is not only expensive but can limit the long-term stability of the device. Carbon derivatives are of great interest as counter electrode material in hole−conductor free TiO2/(ZrO2 or Al2O3)/perovskite/Carbon derivative heterojunction solar cells to substitute noble metallic materials. The hydrophobic and porous carbon derivatives could be the possible solution for high performance cost effective and long term stable Perovskite solar cells (PSCs). To characterize the perovskite- carbon interface, we considered an equivalent electrochemical cell contains Iodide/Tri-iodide redox couple instead of Perovskite. This system has similar energetics as the carbon/perovskite and, at the same time, is more stable. We fabricate Graphite/carbon film of different thickness and follow many procedures to make it stable. The graphite/carbon black nanocomposite film characterised by impedance spectroscopy, transport resistance and double layer capacitance of various carbon films shows that the charge transport is faster in sample 1. The optimum thickness for significant charge transfer is (10µm-14µm) and slow ramp for sintering have added advantage for better stability of nanocomposite film.
Figure1: Transport resistance and double layer capacitance of various types of nanocomposite film specimens.
References:
1. Anyi Mei, Min Hu, Xiong Li, Linfeng Liu, Jiangzhao Chen, Ying Yang, Zhiliang Ku, Tongfa Liu, Michael Grätzel, Yaoguang Rong, Hongwei Han, Science, 345,6194, (2014).

 

[534] THE EFFECT OF PT:RU RATIO ON THE ACTIVITY OF CORE-SHELL METHANOL OXIDATION CATALYSTS

 

Dima Kaplan1, Larisa Burstein1, Yuri Rosenberg1, Inna Popov2, Emanuel Peled3

1 School of Chemistry; Wolfson Applied Materials Research Center
2 School of Chemistry; The Hebrew University Center for Nanoscience and Nanotechnology
3 School of Chemistry; School of Chemistry

The effect of Pt:Ru ratio on the activity of Core-Shell methanol oxidation catalysts

D. Kaplan*, L. Burstein**, Yu. Rosenberg**, I Popov***, and E. Peled*
*School of Chemistry, **Wolfson Applied Materials Research Center
Tel Aviv University, Tel Aviv, Israel, 69978
***The Hebrew University Center for Nanoscience and Nanotechnology
The Hebrew University of Jerusalem, Jerusalem 91904, Israel
Presenting author contact information: dimakapl@post.tau.ac.il, 03-6406951

Direct methanol fuel cells (DMFCs), using liquid and renewable methanol fuel, have been considered to be a favorable option in terms of fuel usage and feed strategies. However, in order to make DMFC technology a success, real breakthroughs in anode catalysis are necessary with respect to performance and cost. Regarding cost reduction, for early DMFC commercialization, DMFC anode catalyst loadings must drop to a level of <1.0 mg cm−2 from the present 1.0–8.0 mg cm−2.
The purpose of our research was to develop catalysts with high platinum utilization, and also to study the correlation between the surface concentrations of platinum and ruthenium and the methanol oxidation activity. Core – Shell catalysts have the potential to improve Pt utilization and reduce the currently needed Pt loadings in DMFC. Several nano-size (2-3nm) Core – Shell, XC72 supported catalysts were synthesized in a two-step successive deposition process with NaBH4 as the reducing agent. The catalysts were composed of IrNi core and varying Pt:Ru ratio shell, from Pt:Ru=0.3 to Pt:Ru=4. The structure and composition of these core-shell catalysts were determined by EDS, XPS, TEM and XRD. Electrochemical characterization was determined with the use of cyclic voltammetry. The methanol oxidation activities of the Core – Shell catalysts were studied at 80°C and compared to that of the best commercially available PtRu alloy based catalyst. A 48% improvement of catalytic activity (in terms of A g-1 of platinum) over the commercial catalyst was achieved. These results demonstrate the potential of Core – Shell catalysts in reducing the costs of catalysts for DMFC.

Nano-Electronics

[18] HIGH PERFORMANCE PATTERNED SOURCE ELECTRODE VERTICAL ORGANIC FIELD EFFECT TRANSISTOR

 

Michael Greenman1, Nir Tessler2

1 Electrical Engineering ; Technion
2 Nanoelectronics Center; Department of Electrical Engineering

Vertical organic field effect transistor is a growing research topic due to the industry demand for high-performance low-cost thin-film transistors. In vertical transistors the channel length is determined by the semiconductor film thickness. Therefore, it is possible to fabricate a short channel high-performance device in spite of the organic semiconductors’ relative low mobilities. In our design of vertical transistors the gate electrode is located beneath the source electrode and controls the amount of carriers injected from the source electrode to the organic semiconductor. From the semiconductor the carriers swiftly cross the very short channel length towards the drain electrode. We developed a new fabrication process of n-type and p-type vertical transistors reaching on/off over 105 and current densities above 10mA per cm2. Complementary inverters were successfully assembled using those transistors.

Owing to the patterned source electrode technic, the gate is able to induce an efficient potential barrier lowering between the source electrode and the semiconductor. The fabrication process is compatible with large-area and low-cost fabrication. Using simple one step photo-lithography and lift-off process patterned electrode with holes in sizes of 2-20 µm is fabricated. In this process a blocking layer is added on the top of the source electrode in order to reduce off currents for better performances. To achieve high on/off ratio there must be an injection energy barrier between the source and the organic semiconductor. When using gold as source electrode it is possible to fabricate P-type and N-type transistor at the same process just by changing the organic semiconductor casting.

 

[38] STATISTICAL FIELD EFFECT TRANSISTOR (SFET) – COLLECTIVE USE OF ORGANIC SINGLE CRYSTALS

 

Pramod Kumar1, Yulia Gerchikov2, Shivananda Kammasandra Nanajunda2, Anat Sadeh3, Yoav Eichen2, Nir Tessler3

1 551, Nanoelectronics Center; Technion-Israel Institute of Technology
2 Schulich Faculty of Chemistry; Technion
3 Nanoelectronics Center; Department of Electrical Engineering

Statistical field effect transistor (SFET) – collective use of organic single crystals
Pramod Kumar1, Yulia Gerchikov2, Shivananda Kammasandra Nanajunda2, Anat Sadeh1, Yoav Eichen2, Nir Tessler1
1. Nanoelectronics Center, Department of Electrical Engineering, Technion, Haifa, Israel. 2. Schulich Faculty of Chemistry, Technion, Haifa, Israel.
Manufacturing organic field effect transistors (OFETs) from single crystals requires complex procedures for preparation of single crystals and their alignment at the exact right position. This is in contrast to the ease of fabrication of organic thin film transistors (OTFTs) through either spin coating, printing, or various evaporation methods. There have been a great deal of research in single crystal transistors as it offers high mobility and better device performance and stability due to less defects and grain boundaries than the thin films. Here we demonstrate a new type of transistor which can be prepared with similar ease as thin films but is based on collective use of single crystals. The fabrication is carried out with the aid of stencils mask pattern to yield a device structure we call Organic single crystallites Statistical Field Effect Transistor (OSFET). The concept of the statistical FET (SFET) structure is to first grow many crystallites on gate dielectric such that they form a discontinuous poly crystalline layer of sizes smaller than the channel length. Through one additive step that deposits conducting round disks, over the entire area, the crystallites become inter-connected. In fact, the new device is now being composed of many transistors interconnected in series and in parallel. The odds that a given crystallite is being contacted on both sides and the number of crystallites connecting two conducting circles are a statistical issue and hence the name of this structure: statistical field-effect transistor (SFET).
Our results suggest that unlike single crystal transistors, OSFETs do not require tedious fabrication process, can be easily prepared with the aid of a single additive step.

 

[73] SYNTHESIS AND CHARACTERIZATION OF LARGE-SCALE CVD MOS2

 

Chen Stern1, Doron Naveh1

1 Bar-Ilan University; Bar-Ilan University

Poster submission
Synthesis and Characterization of Large-scale CVD MOS2

Chen Stern and Doron Naveh,
Faculty of Engineering, Bar-Ilan University
chenstern28@gmail.com, doron.naveh@biu.ac.il
the zero
bandgap of graphene limits its applications in nanoelectronics
and optoelectronics
the zero
bandgap of graphene limits its applications in nanoelectronics
and optoelectronics

Few-layer molybdenum disulfide (MoS2) is a semiconductor material with outstanding potential for high-performance and low-power electronic devices. Among its prominent properties are large bandgap, high quantum luminescence efficiency, relatively high electron mobility, and chemical stability. Field effect transistors show excellent on-off current ratio, low subthreshold swing and high photo responsivity. The emergence of viable technologies based on MoS2 requires high quality, wafer-scale samples. Here we report on synthesis of large-area of MoS2 films on SiO2 substrates using a chemical vapor deposition (CVD). Our samples have long-range order and thickness uniformity. The quality the MOS2 is evaluated by the signature of Raman scattering. Electrical characterization of MOS2 based transistors synthesized by CVD is to be presented.

 

[95] ENERGETICS OF ALL METAL OXIDE JUNCTIONS

 

Kevin Rietwyk1

1 Bar Ilan University; Bar Ilan University

Energetics of All Metal Oxide Junctions
During the 1990s a major breakthrough in thin film technologies was achieved with the application of metal oxide buffer layers between organic/polymer layers and metal electrodes. This improved the energy level alignment between the layers, resulting in a drastic enhancement in the performance of a range of devices. There has since been growing interest in active metal oxide layers, due to their high abundance, stability, and low-cost processing. Consequently, metal oxides are more frequently grown as adjacent layers in thin film devices. However, the underlying mechanisms that determine the energetics across all metal oxide interfaces have yet to be extensively investigated. To address this shortcoming we have developed an innovative depth profiling method.
Exploiting the proven combinatorial metal oxide growth techniques we deposit a metal oxide layer with a thickness gradient onto a homogeneous metal oxide layer. Depth profiling is then achieved by laterally scanning the energetics across the sample using scanning Kelvin probe, air photoemission and UV-Vis optical analysis and correlating the measured properties of the layer to the thickness. From this an entire band diagram of the entire active depth of the junction can be developed. To demonstrate the power of this technique we will provide a complete band diagram of the TiO2-Co3O4 heterojunction which has recently shown promise in all oxide photovoltaics and water splitting.

 

[133] TOWARD SINGLE ELECTRON TRANSISTOR DEVICE BASED ON 2D TMD

 

Eldad Peretz1, Doron Naveh2

1 Bar Ilan University; Faculty of Engineering
2 Bar-Ilan University; Bar-Ilan University

Toward Single Electron Transistor device based on 2D TMD
Eldad Peretz and Doron Naveh
Faculty of Engineering, Bar-Ilan University

Two-dimensional layered materials are considered promising for advanced technologies due to their physical and chemical properties that are suitable for advanced electronic applications including nanoelectronics, optoelectronics and spintronics.
Within this class of materials, the transition-metal dichalcogenides (TMDs) and particularly single layer molybdenum disulfide (SL-MoS2) are amongst the most promising semiconductors for applications in nanoelectronic and in quantum information processing devices. These materials are under extensive research for device applications and for physical phenomena possessed by them, including field effect transistors, photodetectors, cathodoluminescent diodes, magneto-transport measurements and more.
Herein, we discuss a prototype of devices that have yet been demonstrated on TMDs: single electron transistor (SET). SET devices have high sensitivity to changes in the surrounding electrostatic field. Even minor changes in proximity to the device will affect the conductance through the SET and hence will be observable in measurements. This property makes SET an important building block in realization of quantum bits (Qubits) and serves as charge sensor and electrometer in nanoelectronic and quantum information processing devices.

 

[173] ELECTRIC CONDUCTIVITY OF METAL ORGANIC FRAMEWORK-BASED COMPOSITIONS

 

Arie Borenstein1, Doron Aurbach2

1 Bar Ilan University; Bar Ilan University
2 Bar-Ilan University; Bar-Ilan University

Electric conductivity of metal organic framework-based compositions
A. Borenstein*, O. Fleker, R. Lavi, L. Benisvy, S. Ruthstein, and D. Aurbach
The Chemistry Department, Faculty of Exact Sciences, Bar Ilan University, Ramat-Gan, Israel, 5290002
* Corresponding author: Doron.Aurbach@biu.ac.il

ABSTRACT
Metal Organic Frameworks’ (MOFs) unique properties make them superb candidates for many high-tech applications. However, their non-conducting character suppresses their practical utilization in electronic and energy systems. Using the familiar HKUST-1 MOF as a model system, we present a new method of gaining electrical conductivity to otherwise non-conducting MOFs by preparing MOF nanoparticles within the conducting matrix of mesoporous activated carbon (AC). This composite material was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), gas adsorption measurements, and electron paramagnetic resonance (EPR) spectroscopy. We show that MOF nanoparticles grown within the carbon matrix maintain their original unique crystalline and surface area. Owing to the composition process, EPR measurements surprisingly revealed a copper signal that was not achieved so far. We could analyze for the first time the complex EPR response of HKUST-1. We demonstrate the high conductivity of the MOF composite and discuss various factors that are responsible for these results. Finally, we present an optional application for using the conductive MOF composite as a high-performance electrode for pseudo capacitors.

 

[182] SPATIALLY-RESOLVED DOPING OF TWO-DIMENSIONAL MATERIALS USING FUNCTIONAL POLYMERS

 

Ofer Sinai1, Hadas Alon2, Ashwin Subramaniam3, Egle Puodziukynaite4, Ryan Selhorst4, Todd Emrick4, Doron Naveh1

1 Bar Ilan University; Bar Ilan University
2 Bar-Ilan University; Bar Ilan University
3 Department of Industrial and Mechanical Engineering; University of Massachusetts,
4 Department of Polymer Science and Engineering; University of Massachusetts,

Two-dimensional (2D) semiconductors based on the Mo and W family of layered transition metal dichalcogenides (TMDCs) are highly attractive for digital logic and near-IR photonics. However, their widespread incorporation into devices is hindered by the lack of robust strategies for controlling carrier densities through doping, as well as by the difficulties inherent in precise, scalable engineering of semiconductor heterojunctions. Taking advantage of the exquisite sensitivity of 2D materials to their immediate environment, we apply an ‘extrinsic’ approach to work-function engineering and carrier doping of TMDCs. Using e-beam lithography techniques, mechanically exfoliated MoS2 is contacted with Cr/Pd electrodes, whereby its transport properties are assessed. Additional patterning steps allow us to selectively expose the device to specially-designed functional polymers, yielding precise spatial control over carrier doping within different regions of the same flake. This control makes possible the construction of basic building blocks of integrated circuits, e.g., diodes, bipolar transistors, and inverters. This new class of hybrid polymer-2D materials promises scalable and low-cost engineering of optoelectronic functionality within TMDC monolayers.

 

[193] GUIDED GROWTH OF GALLIUM NITRIDE NANOWIRES WITH IMPROVED ELECTRICAL PROPERTIES

 

Ella Sanders1, Regev Ben Zvi Bechler1, Ernesto Joselevich1

1 Department of Materials and Interfaces; Weizmann Institute of Science

Semiconductor nanowires (NWs) are important materials, found today in the basis of many potential nanotechnological applications and scientific research. Recently, our group has reported a new approach for the guided growth of aligned horizontal GaN, ZnO and ZnSe NWs on different substrates (sapphire (α-Al2O3), quartz, SiC, spinel), via the vapor-liquid-solid (VLS) mechanism. This new method enables control over the NWs location, growth direction and crystallographic orientation, and can lead to specific design and assembly of nanodevices. GaN specifically is an important semiconductor having a wide direct band-gap of 3.4 eV in the UV range, suitable for different electronic and optoelectronic applications. GaN NWs are unintentionally n- doped due to nitrogen vacancies and/or oxygen impurities, which often causes a high concentration of charge carriers. This often reduces their field-effect mobility, and hence the performance of nanowire-based transistors is affected. Here we demonstrate the control of the unintentional-doping level, using alumimium as an oxygen getter agent in the synthesis of GaN nanowires. In the chemical vapor deposition (CVD) system, the alumimium precursor can react with the oxygen in the reactor, originating from the Ga2O3 precursor and different impurities in the system. This can possibly allow the growth of GaN NWs with less oxygen impurities in the lattice, bringing down the n-doping level. The guided nanowires were examined in different compositional analysis methods (EELS spectroscopy, EDS and photoluminescence), which showed that the aluminium is not incorporated in the GaN nanowire lattice (no more than 2%). Electrical measurements show higher resistivity for GaN NWs grown with aluminium, and much higher response to gating measurements. These findings can indicate that the aluminium probably acts as an oxygen getter agent during the synthesis. This gettering method is thus shown to enable control of the electrical properties of guided nanowires.

 

[243] ELECTROCHEMICAL BIOSENSORS FOR POINT-OF-CARE MONITORING IN MENTAL HEALTH

 

Hadar Ben-Yoav1

1 Department of Biomedical Engineering; Ben-Gurion University of the Negev

Electrochemical biosensors for point-of-care monitoring in mental health
Hadar Ben-Yoav 1,2,*, Thomas E. Winkler 2, George Banis 2, Sheryl E. Chocron 2, Eunkyoung Kim 2, Deanna L. Kelly 3, Gregory F. Payne 2, and Reza Ghodssi 2
1 Ben-Gurion University of the Negev, Beer Sheva, Israel; 2 University of Maryland, College Park, 3 University of Maryland School of Medicine, Baltimore, Maryland, United States; * Corresponding author: benyoav@bgu.ac.il
We present the first demonstration of an electrochemical micro-system for real-time biosensing of the antipsychotic clozapine (CLZ) towards point-of-care Schizophrenia treatment monitoring. The biosensor is based on a multi-sensor approach that integrates chitosan-modified semi-selective sensors, i.e. a catechol-chitosan redox cycling system and a carbon nanotubes (CNTs) –chitosan composite (Figure 1). Here, we show the development of the microfabricated biosensor and the miniaturization of the redox-cycling system that results in the amplification of the electrochemical signal generated by CLZ (Figure 2). The catechol-chitosan integrated biosensor demonstrates a sensitivity of 54 µC×mL/cm2×µg and a limit-of-detection of 0.8 µg/mL (Figure 3), that enables detection in high interference biological samples such as Schizophrenia patients’ serum.
References:
1. H. Ben-Yoav, T.E. Winkler, E. Kim, S.E. Chocron, D.L. Kelly, G.F. Payne, R. Ghodssi, Electrochimica Acta 130, p. 497, 2014.
2. H. Ben-Yoav, S.E. Chocron, T.E. Winkler, E. Kim, D.L. Kelly, G.F. Payne, R. Ghodssi, Electrochimica Acta 163, p. 260, 2015.

 

[283] ULTRASENSITIVE GAS PHASE DETECTION OF AIRBORNE MOLECULAR CONTAMINATION IN METROLOGY APPLICATIONS

 

Or Zolti1, Fernando Patolsky2

1 Tel Aviv University; Department Of Material Science and Engineering
2 School of Chemistry; School of Chemistry

ULTRASENSITIVE GAS PHASE DETECTION OF AIRBORNE MOLECULAR CONTAMINATION IN METROLOGY APPLICATIONS
Or Zolti* and Fernando Patolsky
Abstract
Contamination of airborne molecular contamination (AMC) is responsible for numerous defects in integrated circuit manufacturing [1],[3]. The ability to sense these contaminations “in-situ” within the fabrication line vacuum chambers will allow yield increase and cost reduction. Effective detection of those AMC with selective properties are vital to insure that contaminators are not damaging the processes and machinery within the very large scale integration (VLSI) production line [3]. In our research the detection was done by exploiting the electric characteristics of Si nanowire field-effect transistors sensors (Si NWFET). The use of SiNW FET are showing promising capabilities in the recognition of the contaminating species, even at low concentrations as low as 400ppt (parts-per-trillion) in their gaseous phase. SiNW FETs provide advantages when compared to other sensing methods such as: low power consumption, gate voltage controllability, simple multiple device signals analysis, and their small dimensions [2]. We will present a novel use of SiNW FETs to detect AMCs, with detection times of a few seconds. By heating permeation tubes in an oven, with a constant flow of N2 carrying gas, we were able to control the concentration of the AMCs. In order to detect the AMCs we have modified the SiNWs surface with different silane-derivative molecular layers, and tested the change of electrical current through the NWs devices in response to their interaction with the AMCs molecular species. The AMC molecules, physisorbed to the modified SiNWs surface, induced a change in the surface potential of the NW-based sensing devices, which resulted in change of current through the NWs. In this work we have successfully tested the presence of Acetone and NMP molecules, while using different modifications.

 

[294] A CUSTOMIZED NANOWIRE-BASED SENSING ARRAY ON PROGRAMMABLE CMOS CHIP

 

Beatrice Miccoli1, Alberto Bonanno2, Alessandro Sanginario2, Valentina Cauda3, Danilo Demarchi4

1 Politecnico DI Torino; Department of Electronics and Telecommunications
2 Center for Space Human Robotics@polito; Istituto Italiano DI Tecnologia
3 Center for Space Human Robotics@polito and Politecnico DI Torino; Politecnico DI Torino
4 Center for Space Human Robotics@polito and Politecnico DI Torino; Department of Electronics and Telecommunications – Politecnico DI Torino

State-of-art research on high-performing sensors often rely on the remarkable and distinctive properties of nano-structures. Indeed, nanomaterials can interact with the surrounding environment at the nanoscale leading to sensors with improved sensitivity and limit-of-detection. Accurate Read-Out-Circuits (ROCs) are needed to directly measure small variations of resistance and capacitance of the nanomaterial during the sensing process. The presented multi-sensor CMOS platform (Figure 1-d inset), integrates the electronics able to read-out, in real-time, the conductance of different nanostructures deposited onto 24 couples of metal electrodes placed on the chip surface. The 130 nm CMOS chip both controls the nanostructure deposition by enabling a dielectrophoresis (DEP) signal on each couple of electrodes and reads-out the nanostructure electrical properties. DEP does not require any further contact deposition allowing high chip reusability by removing the nanostructure through sonication. The nanostructure/electrodes electrical contact is improved through a chemical CMOS post-processing. Therefore, the top surface of the original Al electrodes is covered with Au (Figure 1-a), less prone to oxidation. As proof-of-concept, zinc oxide nanowires (ZnO-NWs) are deposited across different couples of gold electrodes (Figure 1-b) successfully exploiting the DEP circuit on-chip. The variation of the ZnO-NW resistance, RNW, under UV-visible light is then investigated using the chip ROCs. As expected1, RNW significantly decreases (up to 93% of the dark value) for increasing irradiances (Figure 1-d). To further test the multi-sensing concept, Mo6S4I6-NWs are also integrated on the same chip (Figure 1-c) enabling the DEP signal on different electrodes. This opens the future for new combined sensing measurements potentially involving different NWs and thus sensing properties, at the same time.
Figure-1. (a) CMOS post-processing. (b) SEM image of a ZnO-NW across gold electrodes. (c) DEP results with: ZnO-NWs (l≈10 µm, d≈600 nm) and Mo6S4I6-NWs (l≈15 µm, d≈100 nm). (d) ZnO-NW UV-visible light characterization on chip (inset).

References
[1] B. Miccoli, A. Bonanno, et al., in IEEE 38th Int. Spring Seminar on Elec. Tec. (ISSE), 2015, 431.

 

[297] DOPING EFFECT ON BSA SELF ASSEMBLED MONOLAYERS ELECTRICAL PROPERTIES:CHEMICALLY RESOLVED ELECTRICAL MEASUREMENTS ANALYSIS

 

Edith Beilis1

1 Tel Aviv University; Tel Aviv University

Doping Effect on BSA Self Assembled Monolayers Electrical Properties:
Chemically Resolved Electrical Measurements Analysis
Edith Beilis1, Bogdan Belgorodsky2, Ludmila Fadeev2, Hagai Cohen*3, Shachar Richter*1
1 Center for Nanoscience and Nanotechnology, 2 School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University
3 Department of Chemical Research Support, Weitzman Institute of Science, Rehovot
E-mail address: edithno@post.tau.ac.il
Abstract:
Evidence for considerable improvement in conductivity of Self Assembled Monolayers (SAMs) composed of Bovine Serum Albumin (BSA , a transport protein without redox activity) via complexion with tetraphenyl-21H,23H-porphine (TPP) and its metallo- derivatives with copper and iron is provided. This is compared to the properties of the bare BSA and its corresponding monolayer.
As we have previously shown1,2,the doping action, namely the incorporation (non covalently) of small hydrophobic molecules to BSA, affects inter and intra molecular forces and thus affects the surface induced conformational changes of BSA upon adsorption to gold. This phenomenon has been also correlated to the morphological properties of the corresponding SAMs as well as changes in BSA molecules dehydration upon adsorption.
By using the unique technique of Chemically Resolved Electrical Measurements (CREM)3,4 we provide I-V characteristics of selected sub-surfaces domains (specific chemical elements) within the monolayer along with X-ray photoelectron spectroscopy (XPS) measurements. Thus the doping effect on the layer’s electrical properties is evaluated in regards to: its morphological properties as well as intrinsic properties such as specific elemental tendency to accumulate charge (electrons/holes).
(1) Beilis, E.; Belgorodsky, B.; Fadeev, L.; Cohen, H.; Richter, S. Journal of the American Chemical Society 2014, 136, 6151.
(2) Mentovich, E.; Belgorodsky, B.; Gozin, M.; Richter, S.; Cohen, H. Journal of the American Chemical Society 2012, 134, 8468.
(3) Cohen, H. J Electron Spectrosc 2010, 176, 24.
(4) Doron-Mor, H.; Hatzor, A.; Vaskevich, A.; van der Boom-Moav, T.; Shanzer, A.;
Rubinstein, I.; Cohen, H. Nature 2000, 406, 382.

 

[327] LIGHT DIRECTION DEPENDENT PLASMONIC ENHANCED GAN/ALN QUANTUM CASCADE DETECTOR

 

Matias Katz1

1 Technion; Technion

Light direction-dependent plasmonic enhanced GaN/AlN quantum cascade detector
Matias Katz1*, Asaf Pesach1, Etienne Giraud2, Martin Denis2 ,Ofir Sorias1, Lior Gal1, Meir Orenstein1, Nicolas Grandjean2, and Gad Bahir1

1Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
2Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
Author e-mail address: matiask@technion.ac.il
The Quantum cascade detector (QCD) has emerged in recent years as an alternative for quantum well infrared photodetector (QWIP). The fundamental building-block of a QCD consists of an active quantum well (QW) where electron excitation occurs upon photon intersubband (ISB) absorption, and multi-quantum well extractor that transfers the excited electron to the ground level of the following active QW. Major drawback of the QCD in applications based on normal light incidence is related to the polarization selection rule of QW inter-subband (ISB) transitions, allowing absorption only for an electric field polarized perpendicular to the QW layers (Ez). The use of two dimmensional metallic holes arrays (MHAs) allows coupling surface plasmons (SP) to absorption region of the QCD. The generated SP is a TM mode thus exhibits a dominant electric field component normal to the surface that is the proper polarization for exciting the ISB resonance. Recently, a normal-incident plasmonic GaN/AlN QCD was introduced by our group. In the present work we show experimentally and by simulation that plasmonic enhancement performance of a QCD integrated with top MHA depends on the direction of the incidence light; normal Front Illumination (FI) or Backside Illumination (BI). In the study, it is shown that BI considerably increases the light coupling strength compared with FI. The peak responsivity is incresead from 1.77 to 2.72 mA/W at 1.82 μm by changing the light direction. For studying the effect of plasmonic Ez field depth decay on QCD performance, further work is being done on a new QCD sample that consists of 3 active periods and the results will be presented at the conference.

 

[336] TOWARDS ELECTRICAL TRANSPORT MEASUREMENTS THROUGH SINGLE DNA MOLECULES

 

Roman Zhuravel1

1 Institute of Chemistry and The Harvey M. Krueger Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem; Givat Ram

Towards electrical transport measurements through single DNA molecules
Roman Zhuravel1, Haichao Huang1, Haya Dachlika1, Avigail Slutzkin1, Dvir Rotem1, Shalom Wind2 and Danny Porath1
1 Institute of Chemistry and The Harvey M. Krueger Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Israel
2 Department of Applied Physics and Applied Mathematics Center for Electron Transport in Molecular Nanostructures, Columbia University, New York, USA

The field of Nano-electronics concentrates a lot of interest from technological and scientific point of view. The technological interest is obvious as the semi-conductor industry approaches the nanometric scales and seeks for further device miniaturization. It raises many scientific questions and challenges, one of them is understanding the charge transport in single molecules. While charge transport in the solid state has been widely researched, for large single molecules many fundamental questions remain unsolved.
DNA is a good model molecule for many polymeric systems and its structure suggests the possibility for significant charge transport. Charge migration along DNA molecules has attracted scientific interest for over half a century. However, due to the many free parameters concerning these experiments, a variety of results were achieved triggering an ongoing scientific debate on the DNA molecule conductivity. Our goal in this research is to eliminate as many degrees of freedom as possible.
We create dimers of gold nanoparticles bridged by exactly one DNA molecule. Each nanoparticle is connected to the DNA trough one thiol. This system is very well-defined with minimum number of unknown parameters. The dimer is brought to a small gap between pointing electrodes by dielectrophoresis for further electrical characterization. Our system enables precise measurements with very good control of many environmental parameters such as temperature, atmosphere etc. These measurements have already generated promising preliminary results.

 

[337] STATISTICAL ANALYSIS OF PHOTO-INDUCED SWITCHING IN NANO ANTENNA-JUNCTIONS EMBEDDED WITH PBSE SEMICONDUCTOR COLLOIDAL QUANTUM DOTS.

 

Iftach Ilsar1, Arthur Shapiro2, Efrat Lifshitz2, Yoram Selzer1

1 Tel Aviv University; School of Chemistry
2 Technion; Faculty of Chemisrty

Abstract
Statistical analysis of photo-induced switching in nanoantenna-junctions embedded with PbSe semiconductor colloidal quantum dots.
We study the influence of light on electron transport in plasmonic nanoantenna electrical junctions embedded with ~5nm PbSe Semiconductor Colloidal Quantum Dots (SCQD). In these junctions, the origin of photocurrents may be quite involved owing to several possible mechanisms which influence the junction’s conductance under illumination. These may include photo excitation of the QDs, interaction of photons with the metal leads, plasmonic enhancement of the electric field in the junction’s gap, heating effects and more. Distinguishing between the different photocurrent constituents is very challenging and yet highly important for the use of such junctions in numerous applications. To tackle this difficulty, we exploit the unique phenomena of switching in SCQD junctions, conventionally attributed to random charge trapping events in trap states of the SCQD, to distinguish between the various possible photo-effects by statistical analysis methods.

 

[356] AMINO ACIDS BASED-MONOLAYERS FOR TUNING SURFACE ELECTRONIC PROPERTIES OF CONDUCTIVE OXIDES

 

Naomi Kramer1, Nurit Ashkenasy1

1 Ben Gurion University of the Negev; The Department of Materials Engineering

Amino acids based-monolayers for tuning surface electronic properties of conductive oxides
Naomi Kramer and Nurit Ashkenasy
The department of Materials engineering,
Ben-Guriun University of the Negev, Beer Sheva , Israel
Abstract
Organic based optoelectronics devices have a promising potential in various applications. Energy band alignment at interfaces between the organic layers and indium tin oxide (ITO), a commonly used electrode, is extremely important for the efficiency of these devices. Using organic monolayers as a mean to control the work function of the conductive oxide via the molecular dipole moment and/or charge redistribution has shown to be an effective way for tailoring the interfacial electronic properties without hindering the overall performance of such devices. In this respect, amino acids provide a versatile platform to control ITO work function, since they easily form monolayers by attaching to the surface through their carboxylic residue, enabling their side groups to tune the electronic properties. Here, we show the effect of selected amino acids’ side chain on the electronic properties of ITO.
Monolayers of Lysine, Glutamic acid and Tyrosine were assembled on ITO in order to study the effect of positively charged, negatively charged and aromatic side chains (respectively) on the work function and surface photovoltage of the surface, while bare ITO and Glutamine (uncharged side chain) were chosen as reference. Our results show that Lysine monolayers decrease the work function due to positive dipole moment while Tyrosine monolayers increase the work function due to negative dipole moment. Glutamic acid monolayers decrease the work function, probably due to adsorption through both carboxylic groups. Surface photovoltage spectroscopy studies show an increase in the band bending in all cases, except for Tyrosine, in respect to bare ITO, showing charge redistribution at the surface. These results present a simple and versatile process for tuning the electrical properties of conductive oxide surfaces using amino acids.

 

[358] ELECTRICAL CHARACTERIZATION OF 1D MOLECULAR STRUCTURES

 

Avigail Stern1, Dvir Rotem1, Suzanna Azoubel2, Shlomo Magdassi3, Danny Porath1

1 Hebrew University; Givat Ram
2 The Hebrew University of Jerusalem; Givat Ram
3 The Hebrew University of Jerusalem; Chemistry

Electrical Characterization of 1D Molecular Structures

Avigail Stern1, Gideon I. Livshitz1, Dvir Rotem1, Suzanna Azoubel1, Shlomo Magdassi1, Danny Porath1*

1Institute of Chemistry and The Harvey M. Krueger Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, 91904 Israel
*danny.porath@mail.huji.ac.il
Charge transport through 1D polymers is intriguing, but extremely challenging to research. Detailed research of the mechanism of such transport has been detained, mainly due to shortage of reliable charge transport measurements through such molecules. In order to supply this shortage a reliable measurement setup was recently developed in our lab, that is suitable for measurement of molecules tens to hundreds of nanometers long. This setup involves a stationary gold electrode that is evaporated over the molecules of interest and a conductive AFM tip serving as a second mobile electrode that contacts single molecules protruding from the gold electrode. We used the technique to characterize the conductivity of a SWCNT network before and after HNO3 fume treatment, and concluded that the fumes improve the network conductivity by decreasing the resistance at CNT junctions. In addition we are attempting to implement the technique for measurements of single non-crystalline 1D molecules.

 

[363] ANALYSIS OF THE ROLE OF FILM MORPHOLOGY ON THE PERFORMANCE OF VACUUM DEPOSITED CUPC/C60 SMALL MOLECULE BASED ORGANIC PHOTODIODE

 

Himanshu Shekhar1, Nir Tessler2

1 Technion Institute; Electrical Department
2 Nanoelectronics Center; Department of Electrical Engineering

To achieve efficient organic photodiode (OPD) for their use as photodetector in image sensor, donor and acceptor molecules are co-evaporated to form the photoactive layer in the device. The effect of the mixing ratio of copper-phthalocyanine (CuPc) and C60 in the photoactive layer on the optical and electrical device performance is investigated by solar cell characterization measurements. We find that a 70:30 (vol %) mixing ratio in CuPc:C60 blend gives maximum short-circuit current and highest power conversion efficiency (PCE).
We studied the effect of various active layer thicknesses, ranging from 40nm to 120nm, on the device performance. The results show that the device with 40nm thick active layer has best photodiode characteristic parameters. Morphological analysis using AFM and SEM of 40nm and 120nm films revealed difference in grain sizes and their distribution across the film. Thin film has smaller grains with a well interconnecting network compare to the thick film, this was also confirmed from intensity vs efficiency measurement1. The later measurement also shows higher generation efficiency for the thinner device despite absorbing less light (45% in thin film compare to 70% in thick) as found using optical modeling. Moreover, 34% drop in efficiency, moving from low light intensities to one sun, is observed for thicker film compare to only 10% drop for the thin film. We believe that the superior performance of thin active layer device is associated with the film morphology leading to lower losses.
Our device, a photodiode, has short-circuit current of 7.80 mA/cm2 and 1.80% PCE. The dark current rectification ratio (Ion/Ioff) between -2V and 1V is more than 105 which is better than reported for the similar material system2.
Reference
1. Tzabari, L. and Tessler, N., Role of Charge Transfer States in P3HT-Fullerene Solar Cells. J. Phys. Chem. C, 118(48), 2014, 27681-27689
2. Sullivan, P., et al., Influence of Co-deposition on the Performance of CuPc-C60 Heterojunction Photovoltaic Devices. Applied Physics Letter, 84 (2004)

 

[401] LOCALIZATION OF CHARGE CARRIERS IN MONOLAYER GRAPHENE GRADUALLY DISORDERED BY ION IRRADIATION

 

Erez Zion1

1 Bar-Ilan University; Max and Anna Web St.

Localization of Charge Carriers In Monolayer Graphene Gradually Disordered by Ion Irradiation

Erez Zion1, Alexander V. Butenko1, Leonid Wolfson3, Yuri Kaganovskii3, Amos Sharoni1, Doron Naveh2, Vladmir Richter4, Moshe Kaveh3, Eugene Kogan3, Issai Shlimak3
1 Department of Physics and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, Israel
2 Faculty of Engineering, Bar-Ilan University, Ramat-Gan, Israel
3 Jack and Pearl Resnick Institute, Department of Physics, Bar-Ilan University, Ramat-Gan, Israe
4 Solid State Institute and Physics Department, Technion-Israel Institute of Technology, Haifa, Israel

Gradual localization of charge carriers is studied in a series of micro-size samples of monolayer graphene fabricated on the common large scale film and irradiated by different doses of C+ ions with energy 35 keV. Measurements of the temperature dependence of conductivity and magnetoresistance in fields up to 4 T show that at low disorder, the samples are in the regime of weak localization and antilocalization. Further increase of disorder leads to strong localization regime, when conductivity is described by the variable-range-hopping (VRH) mechanism. A crossover from the Mott regime to the Efros-Shklovskii regime of VRH is observed with decreasing temperature. Theoretical analysis of conductivity in both regimes shows a remarkably good agreement with experimental data.

 

[405] NOVEL ITO SURFACE PASSIVATION BY MOLECULAR ADSORPTION

 

Hela Sasson1, Yulia Furmansky2, Jose .M. Alonso3, Han Zuilhof3, Iris Visoly-Fisher4

1 Ben Gurion University ; Ilse Katz Institute for Nanoscale Science & Technology
2 Ben Gurion University; Ilse Katz Institute for Nanoscale Science & Technology
3 Wageningen University; Wageningen University
4 Swiss Institute for Dryland Environmental and Energy Research; Swiss Institute for Dryland Environmental and Energy Research

Hela Sassona, Yulia Furmanskya, b, c, Jose M. Alonsod, Han Zuilhofd, Iris Visoly-Fishera, c.
aDept. of Solar Energy and Environmental Physics, Jacob Blaustein Inst. for Desert Research, Sede Boqer campus, bDept. Of Materials Eng., cIlse Katz Institute for Nano-scale Science and Technology, Ben-Gurion University of the Negev, Israel.
dLaboratory of Organic Chemistry, Wageningen University, Wageningen, The Netherlands.
Indium tin oxide (ITO) is widely used as a transparent electrode in optoelectronic devices. ITO is known to have in-gap surface states due to its non-perfect nature, which affect charge transport across its interface with other (opto)electronic materials [1]. Accordingly, ITO/PEDOT:PSS junctions have shown significant UV photoconductance due to photoinduced discharging of ITO surface states resulting in a decrease of the ITO’s surface band bending. In contrast, we show that 1-alkenes adsorbed in ITO surface via the formation of an C−O−In(Sn) linkage [2], and n-phosphonic acids adsorbed via OH, have shown negligible such photoconductance. Furthermore, Kelvin probe measurements of the work function showed very small surface photovoltage. This possibly indicates passivation and discharging of ITO surface states by adsorption via C−O−In(Sn) or phosphonic acid linkage. Passivation of surface states and elimination of the ITO photo-response could be highly significant for the use of ITO in optoelectronic devices such as OLEDs and solar cells.

[1] Y. Gassenbauer and A. Klein, “Electronic and Chemical Properties of Tin-Doped Indium Oxide (ITO) Surfaces and ITO/ZnPc Interfaces Studied In-situ by Photoelectron Spectroscopy” J. Phys. Chem. B. 110, pp. 4793-801,2006.
[2] Y. Li and H. Zuilhof, “Photochemical grafting and patterning of organic monolayers on indium tin oxide substrates” Langmuir 28, pp. 5350–9, 2012.

 

[408] THERMOELECTRIC EFFECT IN GRAPHENE BIPOLAR JUNCTION

 

Moshe Kirshner1

1 Bar Ilan University; Bar Ilan University

Eldad Peretz, Doron Naveh

Thermoelectric effects in graphene, a two dimensional electron gas of Dirac Fermions are well recognized.  Here we induce bipolar junctions in graphene field effect transistors via interfacial doping and study the temperature-dependent transport. The character of charge carrier distribution is devised from transport measurements and the thermal generations, and the resulting thermo-power is estimated in asymmetric interdigitated transistors.

 

 

[410] GRAPHENE PN JUNCTIONS ACHIEVED BY SOFT DOPING WITH PSBMA

 

Hadas Alon1

1 Bar-Ilan University; Bar Ilan University

Graphene pn Junctions Achieved by Soft Doping with PSBMA
Hadas Alon1,2, Vlada Artel1,2, Chaim N. Sukenik1, Ashwin Ramasubramaniam3, Egle Puodziukynaite4, Ryan Selhorst4, Todd Emrick4, and Doron Naveh2

1 Department of Chemistry and Bar-Ilan Institute for Nanotechnology and Advanced Materials, Ramat-Gan 52900
2 Faculty of Engineering and Bar-Ilan Institute for Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900
3 Department of Industrial and Mechanical Engineering, University of Massachusetts, Amherst, MA
4 Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA
Graphene, a single layer of carbon atoms arranged in a honeycomb lattice, is one of the most fascinating and promising electronic materials known. While its atomic thickness is a significant advantage in many respects, this unique structure creates a serious challenge in developing the controlled modification of its charge carrier concentration. In this work, we demonstrate a viable strategy for achieving substantial control over the charge carrier concentration in graphene. It is achieved by using patterned structures of polymers that exhibit charge transfer with graphene. The patterning is achieved by conventional lithography and the work-function engineering is provided by the charge transfer between the graphene and the overlaid polymer. This conceptually simple and versatile approach will be applied to devices built around graphene-based PN junctions that can be used in photodetectors and transistors.

 

[429] THE UPPER LIMIT OF CONDUCTANCE ACROSS A SINGLE MOLECULE

 

Tamar Yelin1, Richard Korytar2, Nirit Sukenik1, Ran Vardimon1, Bharat Kumar3, Colin Nuckolls3, Ferdinand Evers2, Oren Tal1

1 Weizmann Institute of Science; Chemistry
2 Regensburg University; Theoretical Physics
3 Columbia University; Chemistry

Single molecules set the ultimate miniaturization limit of conductive components in electronic circuits. A major challenge of molecular electronics is to achieve high and robust conductivity. However, it is not clear what is the upper boundary for conductance across a single molecule and what are the factors that would determine this limit. We addressed these questions by studying the effect of molecule length on the conductance in metal-molecule-metal junctions, based on a series of oligoacene molecules. We found that the conductance can reach an upper limit where it is independent on molecule length. Furthermore, we found that this limit can be controlled by rational orbital hybridization at the metal-molecule interface. Interestingly, the evolution of conductance towards its upper limit can be understood with the aid of a simple analytical model. Our findings shed light on the mechanisms that determine the upper limits for conductance across molecules, providing guiding principles for the design of highly conductive metal-molecule interfaces.

 

[430] TOWARD SINGLE ELECTRON TRANSISTOR DEVICE BASED ON 2D TMD

 

Eldad Peretz1, Doron Naveh2

1 Bar Ilan University; Faculty of Engineering
2 Bar-Ilan University; Bar-Ilan University

Toward Single Electron Transistor device based on 2D TMD
Eldad Peretz and Doron Naveh
Faculty of Engineering, Bar-Ilan University

Two-dimensional layered materials are considered promising for advanced technologies due to their physical and chemical properties that are suitable for advanced electronic applications including nanoelectronics, optoelectronics and spintronics.

Within this class of materials, the transition-metal dichalcogenides (TMDs) and particularly single layer molybdenum disulfide (SL-MoS2) are amongst the most promising semiconductors for applications in nanoelectronic and in quantum information processing devices. These materials are under extensive research for device applications and for physical phenomena possessed by them, including field effect transistors, photodetectors, cathodoluminescent diodes, magneto-transport measurements and more.
Herein, we discuss a prototype of devices that have yet been demonstrated on TMDs: single electron transistor (SET). SET devices have high sensitivity to changes in the surrounding electrostatic field. Even minor changes in proximity to the device will affect the conductance through the SET and hence will be observable in measurements. This property makes SET an important building block in realization of quantum bits (Qubits) and serves as charge sensor and electrometer in nanoelectronic and quantum information processing devices.

 

[436] NICKEL NANOPARTICLE–BASED PRINTED MAGNETIC SENSORS

 

Leah Ben Gur1, Einat Tirosh1, Amir Segal2, Gil Markovich1, Alexander Gerber2

1 School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences; Tel-Aviv University
2 School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences; Tel-Aviv University

In the past few years printed electronics technology has been developing vastly. This field is oriented towards the low-cost and high volume printed circuit market, where the high performance of conventional electronics is not required.
In this work we have developed printable magnetic thin-films consisting of nickel-nanoparticles ink, which, after drying under controlled conditions, exhibited a significant Extraordinary Hall Effect (EHE) signal (1-10mΩ). The EHE is a well-known effect in the field of ferromagnetic materials, where a voltage proportional to the magnetization across a current carrying magnetic film is generated. The origin of the EHE is spin-orbit scattering that breaks the spatial symmetry of scattered electrons. In cases of our interest the EHE contribution significantly exceeds the ordinary Hall- effect, resulting in a Hall voltage VH that is directly proportional to the magnetization M of the material and as such can be used for sensing magnetic fields.
An EHE sensor can exceed a sensitivity of 104 /T, which is an order of magnitude higher than the best sensitivity achieved in semiconducting Hall materials. An important feature of EHE, particularly relevant for printing technology, is that EHE signal increases with enhancement of electrical resistivity of the material. In other words, the performance of EHE sensors improves with imperfections. Thus, low quality of magnetic films fabricated by printing techniques is not expected to impede their performance.
Ni nanoparticles were selected due to the fairly low oxidation of the Ni on exposure to air, and the relative ease of reduction of the oxide to the metal form. In addition, Ni is a relatively soft magnetic material, which will ensure very low coercivity of the nanoparticle based magnetic sensor, increasing its field sensitivity around zero field.

A typical EHE measurement exhibited from a Ni NP Thin-film

 

[470] A REDOX-REACTIVE NANOWIRE BIOSENSOR FOR MULTIPLEX MONITORING OF CELLULAR METABOLIC ACTIVITY

 

Vadim Krivitsky1, Marina Zverzhinetsky1, Sharon Lefler1, Vladimir Naddaka1, Fernando Patolsky1

1 School of Chemistry; School of Chemistry

A Redox-Reactive Nanowire Biosensor for Multiplex Monitoring of Cellular Metabolic Activity

Vadim Krivitsky†,Marina Zverzhinetsky†, Sharon Lefler†,Vladimir Naddaka† and Fernando Patolsky†

†School of Chemistry, the Raymond and Beverly Sackler Faculty of Exact Sciences,
Tel-Aviv University, Israel

Silicon nanowire field-effect transistors (SiNW FETs) are potential leading candidates for monitoring cellular metabolic activity because they enable real-time, label-free detection of biological and chemical species. However, to conduct sensing in most biosamples of high ionic strength, the detection limit issue related to Debye length has to be resolved. We have developed a novel redox reactive SiNW FET array that enables to perform extracellular real-time multiplex monitoring of metabolites without any pre-processing of the sample, including desalting, directly from the cellular environment. This breakthrough was possible due to a new chemical modification approach performed on the SiNWs surface, which has sensitized them to a redox process on their surfaces. This redox-reactive SiNW FET was successfully utilized for various applications, such as estimating the metabolic activity of bacteria or evaluating chemotherapeutic treatments of cancer cells. Our redox-reactive SiNW-based FETs allow a multiplex, real-time, non-invasive, sensitive, selective, label free and robust detection of various metabolites. This sensing configuration can be performed in a wide range of applications, from food quality control, to point of care and personalized medicine.

 

[484] 1/F NOISE AS A PROBE TO INVESTIGATE THE BAND STRUCTURE OF GRAPHENE

 

Atindra Nath Pal1, Arindam Ghosh2

1 Weizmann Institute of Science; Department of Chemical Physics
2 Indian Institute of Science; Deaprtment of Physics

1/f noise as a probe to investigate the band structure of graphene
Atindra Nath Pal* and Arindam Ghosh
Department of Physics, Indian Institute of Science, Bangalore-560012, India.
The flicker noise or low frequency resistance fluctuations in graphene depend explicitly on its ability to screen external potential fluctuations and more sensitive compared to the conventional time average transport. Here we show that the flicker noise is a powerful probe to the band structure of graphene that vary differently with the carrier density for the linear and parabolic bands. We have used different types of graphene field effect devices in our experiments which include exfoliated single and multilayer graphene on oxide substrate, freely suspended single layer graphene, and chemical vapor deposition (CVD)-grown graphene on SiO2. We find this difference to be robust against disorder or existence of a substrate. Also, an analytical model has been developed to understand the mechanism of graphene field effect transistors. Our results reveal the microscopic mechanism of noise in Graphene Field Effect Transistors (GraFET), and outline a simple portable method to separate the single from multi layered graphene devices.
References

1. Atindra Nath Pal and Arindam Ghosh, Physical Review Letters 102, 126805 (2009).
2. Atindra Nath Pal and Arindam Ghosh, Appl. Phys. Lett., 95, 082105 (2009).
3. Atindra Nath Pal, Ageeth A. Bol, and Arindam Ghosh, Appl. Phys. Lett. 97, 133504 (2010).
4. Atindra Nath Pal et al., ACS Nano, 5, 2075 – 2081 (2011).

 

[487] ELECTRON DELOCALIZATION IN CDSE/CDS TYPE−I CORE−SHELL SYSTEMS: AN INSIGHT FROM SCANNING TUNNELING SPECTROSCOPY

 

Sudipto Chakrabarti1, Biswajit Kundu2, Amlan Jyoti Pal2

1 Weizmann Institute of Science; Chemical Physics
2 Indian Association for the Cultivation of Science; Department of Solid State Physics

Electron delocalization in CdSe/CdS type−I core−shell systems: an insight from scanning tunneling spectroscopy
In this work, we choose CdSe/CdS type-I core−shell nano−heterostructures that evidence confinement of holes to the core only where as electrons are delocalized upto the shell layer1. Such selective confinement occurs due to a low energy−offset of the conduction band (CB) edges between core and the shell, resulting in delocalization of electrons upto the shell layer. Since such delocalization occurs through a thermal assistance, we study temperature dependence of selective delocalization process through scanning tunneling spectroscopy (STS). From the density of states (DOS), we observe that the electrons are confined to the core at low temperatures and above a certain temperature, they become delocalized up to the shell leading to a decrease in the CB of the core−shell system due to widening of quantum confinement effect. We record the topography of the core−shell nanocrystals by probing their CB and VB edges separately. The topographies recorded at different temperatures representing wave−functions of electrons and holes correspond to the results obtained from the DOS spectra. The results evidence temperature−dependent wave−function delocalization of one−type of carriers up to the shell layer in this core−shell nano−heterostructures.

Figure 1. DOS for CdSe/CdS core−shell nanocrystals at different temperatures. The CB and VB edges of the core−shells are marked with vertical lines at the positive and the negative voltages, respectively. Topography of a single nanostructure recorded with a positive or a negative voltage on the substrate and thus probing the CB or the VB of the nanostructures at the temperatures are shown in the right and left side of the corresponding DOS spectra. Dimension of all the images are 12 nm × 12 nm.
Reference
1. J. J. Li, Y. A. Wang, W. Z. Guo, J. C. Keay, T. D. Mishima, M. B. Johnson, X. G. Peng, J. Am. Chem. Soc., 2003, 125, 12567-12575.

 

 

[525] NANOCHANNEL-EMBEDDED SILICON NANOWIRE FETS FOR SINGLE MOLECULE DETECTION

 

Fernando Patolsky1, Alon Kosloff1, Omri Heifler2

1 School of Chemistry; School of Chemistry
2 Faculty of Engineering; Material Engineering Department

Nanochannel-embedded Silicon Nanowire FETs for single molecule detection
Abstract
To increase sensing potential, silicon nanowires sensor arrays are confined along a nano-fluidic channel for the selective single molecule detection. The differential conductance of silicon nanowires, tuned with source-drain bias voltage, has been previously demonstrated to be highly sensitive to molecular charge. In this work, we have fabricated SiNWs-based FET (field-effect transistor) arrays, which based on the nano-channel diameter, show selectivity to molecular size. Furthermore, the nanochannel can also be selective to ion charge, either by modifying channels surface, or utilizing the electrical double layer effect. By applying electrophoresis principle, we can now investigate ion transport, nanochannels electrical cross section properties, and analyze low concentration samples, of high ionic strength, by eliminating the Debye screening length factor. By using simple electrical and optical measuring methods, we can validate molecule transport control in a 100nm thick channel, and distinguish between opposite-charged and size-varied macromolecules.

Nano-Biology

[20] ONE-STEP SYNTHESIS OF HIGH FLUORESCENT BSA QUANTUM DOTS

 

Vijay Bhooshan Kumar1

1 Bar Ilan Institute for Nanotechnology and Advanced Materials; Bina, Department of Chemistry, Bar Ilan University

One-Step Synthesis of high fluorescent BSA quantum dots
Vijay Bhooshan Kumara, Aharon Gedankena, b*

aDepartment of Chemistry and Bar-Ilan Institute for Nanotechnology & Advanced Materials, Bar Ilan University, Ramat-Gan 52900, Israel
bNational Cheng Kung University, Department of Materials Science & Engineering, Tainan 70101, Taiwan
*Corresponding author email: gedanken@mail.biu.ac.il
Fax: 972-3-7384053; Tel: 972-3-5318315

Abstract:
In the current work, we present a new general facile synthesis of BSA (bovine serum albumin) quantum dots from BSA polymer, using hydrothermal reaction. The as-prepared BSA QDs exhibited high quantum yield, high photostabiliy and colloidal stability, and high functionalization efficiency. Interestingly, a high Quantum yield (ca. 40%) was observed with the help of various spectroscopy techniques. However, the advantage of these particles are nontoxic and long stability for the biological applications (in vitro and in vivo) as well as the low cost. Importantly, with high physiological stability, excellent biocompatibility, and homogenous distribution of BSA QD suspension was used to obtain a high contrast bio-imaging and life cell imaging.

 

[48] THE DYNAMIC PROPERTIES OF A DNA ORIGAMI POLYMER STRUCTURE

 

Efrat Roth1

1 Bar- Ilan University; Bar- Ilan University

The Dynamic Properties of a DNA Origami Polymer Structure
Efrat Roth and Yuval Garini
Abstract:
DNA origami is an enabling technique that has been developed during the last decade. Using this technique, one can design almost any kind of form and 3-dimensional structure and build many copies of it in a nanometer scale in a very exact way. Little has been studied about dynamic properties of systems constructed by DNA origami. A polymer-like structure will be built using the DNA origami method, which is a new concept. The polymer consists of rigid rods connected to each other by short double-stranded DNA. The structure allows each rod a wide degree of freedom to move so that it mimics a polymer that may be described by the freely joint chain or other polymer models. The Polymer-like structures will be measured by using tethered particle motion (TPM) method and atonic force microscopy. Both the polymer conformations and dynamics will be studies and it will allow us to check whether the polymer’s properties match the expectations according to the model and the previous measurements of dsDNA. The synthesized polymer-like structures can be used later on for further biophysical studies, as building blocks for biosensors and even for biomedical applications.

 

[52] DESIGN OF POLY(STYRYL BISPHOSPHONATE) NANOPARTICLES GRAFTED ONTO POLYPROPYLENE FILMS FOR INHIBITION OF BIOFILM FORMATION

 

Hanna Adelman-Steinmetz1, Safra Rudnick-Glick2, Michal Natan3, Ehud Banin4, shlomo Margel5

1 The Institute of Nanotechnology and Advanced Materials ; Department of Chemistry
2 Department of Chemistry ; The Institute of Nanotechnology and Advanced Materials, Bar-Ilan University,
3 The Institute for Advanced Materials and Nanotechnology; Bar Ilan University
4 The Mina and Everard Goodman Faculty of Life Sciences; The Institute for Advanced Materials and Nanotechnology
5 Biu; Department of Chemistry & The Institute of Nanotechnology and Advanced Materials

In the past decades bacterial biofilms have been intensively studied for medical and industrial applications. Biofilms cause hazardous contaminations since they have a high resistance to antibiotics and hostile environments. Their unique structure consists of bacterial aggregates which attached to the surface. Ca2+ ions play an important role in the formation of biofilms and impact their stability, architecture, viscosity and strength. Bisphosphonates are a stable chemical analog of the inorganic pyrophosphate and exhibit a high affinity to Ca2+ ions. Bisphosphonates may inhibit the formation of biofilms by acting as sequestering agents for Ca2+ ions. In this study we present a new approach for antibacterial coating, based on bisphosphonates, on polymeric materials while maintaining the mechanical properties. Polypropylene films were treated by O2 plasma to form the desired conjugated-hydroperoxide groups which used as initiator for the graft polymerization of the novel styryl bisphosphonate monomer. The produced bisphosphonate surface coating was confirmed by surface measurements including XPS, AFM, ATR-IR and contact angle. A significant inhibition of the biofilm formation was achieved for both gram-negative (Escherichia coli) and gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) bacteria.

 

[74] ENHANCED ACTIVITY OF IMMOBILIZED PEPSIN NANOPARTICLES COATED ON SOLID SUBSTRATES COMPARED TO FREE PEPSIN

 

David Meridor1, Aharon Gedanken2

1 Bar-Ilan University; Bar-Ilan University
2 Department of Chemistry, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University; Bina

Enhanced activity of immobilized pepsin nanoparticles coated on solid substrates compared to free pepsin

Pepsin, an aspartic peptidase, is used for a variety of applications in industry. Pepsin is sensible to changes in the environment and requires improvement in its catalytic efficiency. Immobilization of pepsin onto solid supports can offer advantages such as easier separation of the enzyme from the product and the possibility of repetitive use of a single batch of enzyme.
In the present work, nanoparticles of pepsin were generated in an aqueous solution using high intensity ultrasound, and were subsequently immobilized on low-density polyethylene (PE) films, or on polycarbonate (PC) plates, or on microscope glass slides. The leaching properties, and the catalytic activity of the immobilized enzyme on the three surfaces were compared. Catalytic activities of pepsin deposited onto the three surfaces as well as free pepsin, without sonication, and free pepsin NPs were compared at various pH levels and temperatures. Compared to native pepsin, pepsin coated onto PE showed the best catalytic activity in all the examined parameters. Pepsin immobilized on glass exhibited better activity than the native enzyme, especially at high temperatures. Enzyme activity of pepsin immobilized on PC was no better than native enzyme activity at all temperatures at pH 2, and only over a narrow pH range at 37 oC was the activity improved over the native enzyme. A remarkable observation is that immobilized pepsin on all the surfaces was still active to some extent at pH 7, while free pepsin was completely inactive. The kinetic parameters, Km and Vmax were also calculated and compared for all the samples. Relative to free pepsin, pepsin coated PE showed the greatest improvement in kinetic parameters (Km= 15 g/L, Vmax= 719 U/mg versus Km= 12.6 g/L and Vmax= 787 U/mg, respectively), whereas pepsin coated on PC exhibited the most unfavorable kinetic parameters (Km= 18 g/L, Vmax= 685 U/mg).
Keywords:
Sonochemistry, pepsin nanoparticles, immobilization, enzyme activity

 

[81] MAGNETIC NANOPARTICLES FOR MANIPULATING NEURONAL GROWTH

 

Michal Marcus1, Moshe Karni1, Koby Baranes1, Noa Alon1, Itay Levy2, Tony Yamin3, shlomo Margel2, Amos Sharoni3, Orit Shefi1

1 Biu; Faculty of Engineering & The Institute of Nanotechnology and Advanced Materials
2 Biu; Department of Chemistry & The Institute of Nanotechnology and Advanced Materials
3 Biu; Department of Physics & The Institute of Nanotechnology and Advanced Materials

The ability to manipulate neuronal organization and growth has extensive implications in neuronal regeneration and tissue engineering. In the present study we use magnetic nanoparticles (maghemite, γ-Fe2O3) as mediators to apply physical forces locally and as carriers of neuronal growth factors. We use these nano-complexes in order to locate cells, promote neuronal growth and affect growth orientation. We designed and generated magnetic fields with controlled magnetic flux densities at multiple scales of size and strength. We fabricated a unique device embedded with micro-patterned pads that can be magnetized selectively. We incubated PC12 cells and primary neurons, in medium enriched with iron oxide nanoparticles conjugated to fluorescent tag. Both types of cells uptake the nanoparticles and turned sensitive to the magnetic stimulation with no cytotoxic effect. Plating PC12 cells atop the micro-patterned device has led to an organized network of clusters of cells. Currently we are mathematically modelling nanoparticles uptake by cells and the organization of magnetized cells in response to various external magnetic fields. In addition, we found that covalent conjugation of the magnetic nanoparticles to nerve growth factor (NGF) which is a critical component in nerve tissue development and repair enhanced the typical effect of NGF. Morphometric and molecular measurements revealed that treatment with the nanoparticle-NGF complex leads to a promoted differentiation progression and to more complex dendritic trees. Stability and signaling pathway assays suggest conjugation to NPs as a method to extend the half-life of NGF, thereby increasing its availability and efficiency. Our study presents an emerging magneto-chemical method for the manipulation of neuronal migration and growth opening new directions in non-invasive neuronal repair.

 

[93] DIRECTING NEURONAL GROWTH IN 3D COLLAGEN HYDROGELS

 

Mereav Antman-Passig1, Orit Shefi2

1 Faculty of Engineering, Bar-Ilan University; Insititue for Nanotechnology and Advanced Materials, Bar-Ilan University
2 Biu; Faculty of Engineering & The Institute of Nanotechnology and Advanced Materials

The ability to manipulate and direct neuronal growth has great importance in the field of tissue engineering, both for neuronal repair and potential medical devices. Since mammalian neurons have limited regeneration abilities creating scaffolds for enhanced regeneration is beneficial. Moreover, guiding and directing neuronal outgrowth can enhance neuronal repair and recovery. Previous studies, including in our lab examined nanoparticles for enhancing neuronal regeneration. Here, we designed a 3D collagen gel-scaffold for neuronal cultures. We further modulated the gel system to create alignment of collagen fibers for directing neuronal growth using nanoparticles.
A collagen hydrogel system was chosen as a 3D ECM analog to best mimic the natural environment of cells. The gels mechanical properties were examined and tuned to achieve desired properties similar to nervous tissue. We compared the neuronal growth in 3D to a 2D model and showed that neurons grown in 3D collagen gels develop significantly longer dendritic trees and neurites. To manipulate neuronal growth we developed a method to align collagen fiber matrix by incorporating magnetic nanoparticles within gels, and exposing the gel to an external magnetic field We showed fiber directionality by analysis of light microscope images via Fast Fourier transform (FFT) and by SEM imaging. We grew neurons in aligned gels for 7 days and followed regeneration process of single cells for up to 7 days. For this purpose we used both primary leech (Hirudo medicinale) neuronal culture, and PC12 as a mammalian analog. Using a designed Matlab script we evaluated cellular direction of growth and compared it to collagen matrix orientation. We further measured morphometric parameters of neuronal growth. Using aligned gels we’ve elongated and directed neuronal growth coinciding with collagen matrix orientation. We also found aligned gels initiate neurite growth patterns similar to growth in 3D control gel.

 

[94] NANO STRUCTURED POROUS SILICON CHIPS FOR NEURONAL DIFFERENTIATION

 

Neta Zilony1, Orit Shefi2, michal Rosenberg3, Esty Segal3, Liran Holtzman4

1 Faculty of Engineering and Institute of Nanotechnology and Advanced Materials; Bar Ilan
2 Biu; Faculty of Engineering & The Institute of Nanotechnology and Advanced Materials
3 Department of Biotechnology and Food Engineering; Technion
4 Department of Biotechnology and Food Engineering,; Technion

Nano Structured Porous Silicon Chips for Neuronal Differentiation

Zilony N.1, Rosenberg M.2, Holtzman L.2, Segal E.2 and Shefi O.1
1Faculty of Engineering, Bar-Ilan University Ramat-Gan, Israel
2Department of Biotechnology and Food Engineering, Technion, Haifa, Israel

Nerve growth factor (NGF) is a well characterized protein and an essential contributor to neuronal differentiation. NGF has shown high pharmacological potential in several models of neurodegenerative diseases. However, growth factors undergo rapid degradation which leads to a short biological half-life. Therefore, its effectiveness in therapeutics is limited. Recent work showed an enhancement in the NGF activity due to covalent conjugation of NGF to iron oxide nanoparticles. In our study, we develop a delivery system, composed of porous Silicon (PSi) chips, that allows sustained release of NGF. Nanostructured PSi is characterized by several particularly appealing tunable properties predestining it for design of drug delivery systems, including high surface area, biocompatibility and ability to degrade completely in physiological environment. Different PSi nanostructures were fabricated by anodic electrochemical etching of single-crystalline Si wafers and the synthesis conditions were adjusted to allow efficient loading of NGF by physical adsorption. In order to study the effect of the combined complex, we used a neuronal like cells model (PC12 cells). NGF is an essential factor for the maintenance and differentiation of PC12 cells in culture. The NGF-chips were added to PC12 cells in culture and the cell began to differentiate. The differentiation was determined by the neurites number, the neurites total length and by molecular markers. The culture was sustained with the NGF-chips up to 14 days. Our work aims to develop new PSi-based carriers for the controlled release of NGF. We demonstrate that NGF entrapment within the PSi allows for its sustained delivery to promote differentiation of PC12 cells without any need of external supplement. Therefore, this novel system will be able to be used in in vivo trails.

 

[108] PDOTS NANOPARTICLES LOAD PHOTOSENSITIZERS AND ENHANCE EFFICIENTLY THEIR PHOTODYNAMIC EFFECT BY FRET

 

Elina Haimov1, Hana Weitman1, Debby Ickowicz2, Zvi Malik2, Benjamin Ehrenberg1

1 Department of Physics; Institute of Nanotechnology and Advanced Materials
2 Faculty of Life Sciences; Bar Ilan University

A new type of nanoparticles, Pdots, and a new methodology of photosensitization are developed to achieve a more efficient photodynamic effect in aqueous solutions and in cells. Pdots are nano-sized particles, composed of conjugated chromophoric polymers coated with PEGylated phospholipids. They exhibit good aqueous colloidal properties, a broad absorption band and a strong and narrow emission band. We show that these characteristics improve biological photosensitization, which is employed in photodynamic therapy of cancer. Pdots nanoparticles load amphiphilic photosensitizers such as Rose Bengal with a high affinity, into the amphiphilic coating, without necessitating covalent attachment. At this close contact, very efficient fluorescence resonance energy transfer (FRET) occurs between the Pdot donor and the sensitizer acceptor. The Pdots serve as broad-band collectors of light, which is funneled, via FRET, to the photosensitizer. Therefore, FRET from them can additively assist to the activity of the acceptor’s energy. The efficient FRET mechanism, strong uptake of the Pdot-sensitizer dyads by MCF-7 adenocarcinoma cells and their enhanced photosensitized killing are demonstrated.

 

[128] A NOVEL APPROACH TO THE DECORATION OF PARYLENE C USING FUNCTIONAL SILICA-TRICLOSAN CO-POLYMERS NANOPARTICLES

 

Rina Binyamini1

1 Bar-Ilan; Biotechnology Chemistry

A Novel Approach to the Decoration of Parylene C Using Functional Silica-Triclosan co-polymers Nanoparticles
Rina B. Binyaminy a, Edith Laux b, Herbert Keppner b, Ehud Banin c
and Jean-Paul Lellouche a*
a Department of Chemistry, Faculty of Exact Sciences, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
b Haute Ecole Arc Ingénierie (HES-SO), CH-2300 La Chaux-de-Fonds, Switzerland
c The Mina and Everard Goodman Faculty of Life Science, Institute for Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
*Corresponding author, Prof. Jean-Paul Lellouche. Email: jean-paul.m.lellouche@biu.ac.il
Both pure silica (SiO2) nanoparticles (SNPs) and functionalized hybrid triclosan/silica nanocomposites (T-SNC) were deposited onto non-functional Parylene C films using a novel, readily executed, one-step decoration method. Unlike previously known methods, this functionalization method of Parylene C films required neither a binding agent nor sophisticated equipment/devices. The SiO2-based NPs anchored on Parylene C substrates were formed via a common base-catalyzed hydrolytic sol-gel method. Regarding the mechanism, it has been assumed that the SiO2 phase precursor (Si(OEt)4, tetraethyl orthosilicate, (TEOS) was first adsorbed and 2D polymerized onto the parylene C film due to hydrophobic interactions that served as an anchor mechanism for further NP growth. This assumption was investigated by comparing thermal behaviors (measured by differential scanning calorimetry, DSC) of parylene C coatings before and after the following specific surface treatment, i.e., (i) first parylene C coating incubation with TEOS followed by (ii) SNP formation and growth from such a TEOS-modified coating surface. Following the same procedure, hybrid thiophene-containing H-SiO2-Tricl NPs were also successfully grown from the surface of a TEOS-modified parylene C film and characterized using high resolution scanning electron microscopy (HR-SEM) and X-ray photoelectron spectroscopy (XPS). In order to obtain deeper insight into the overall functionalization process, the similar hybrid H-SiO2-Tricl NPs that formed in the bulk contacting medium were also isolated and fully characterized for comparison needs. Biological experiments were done as well.

 

[171] SURFACE MODIFICATION OF CELLULOSE NANOCRYSTALS WITH GLYCIDYL METHACRYLATE FOR UV-CROSSLINKING

 

Yuval Nevo1, Yifeng Cao2

1 The Hebrew University of Jerusalem; Robert H. Smith Faculty of Agriculture, Food and Environment
2 The Hebrew University; Robert H. Smith Faculty of Agriculture, Food and Environment

Cellulose nanocrystals (CNCs) are considered to be promising natural components for composite reinforcement, coatings, light-weight foams and hydrogels. Here, CNCs were modified with glycidyl methacrylate (GMA) to introduce C=C groups that can be UV-crosslinked to give CNC based hydrogels and aerogels. The effects of various parameters (molar ratio of GMA to hydroxyl groups, different catalysts, reaction time, temperature, etc.) on the degree of substitution were investigated in order to optimize the reaction conditions. The GMA modified CNCs (GMA-m-CNCs) were characterized by ATR-FTIR, solid state 13C-NMR, POM and XRD. Hydrogels prepared using CNCs modified using the optimized reaction conditions were stable in water and other organic solvents. In addition, methacrylated CNCs were introduced as nanoreinforcing agents inside acrylamide matrices, resulting in enhanced mechanical properties and better crosslinking density of the polymer.

 

[255] REALIZING ULTRASENSITIVE LIVE CELL ATOMIC FORCE IMAGING WITH LARGE FORCE CONSTANT FUNCTIONAL GLASS PROBES

 

Aaron Brahami1, Efrat Zlotkin-Rivkin2, Benjamin Aroeti2, Aaron Lewis1

1 Department of Applied Physics; The Selim and Rachel Benin School of Computer Science and Engineering
2 Hebrew University of Jerusalem; Silberman Life Sciences Institute

Since the invention of atomic force microscopy (AFM) in 1986 live cell imaging has gradually progressed inspite of fundamental limitations in generally applied laser beam deflection (LBD) force sensing. This has been achieved by developing algorithmically based protocols to quantitatively delineate the interactions of AFM probes with cell surfaces. A recent effort was the application of a relatively recent algorithm to image fine cellular protrusions or microvilli, a previously unachievable goal [1]. For this advance ultrasoft silicon probes with cantilever force constants of 0.0611N/m were required. A significant next step would be to implement the same ultrasensitive live cell imaging with an important class of large force constant (1-10N/m) functional glass probes for applications such as near-field scanning optical microscopy (NSOM), AFM sensing with patch clamping pipettes [1], scanning electrochemical microscopy etc. In the presentation this next step in live cell imaging is described, with considerable import for scanned probe imaging of live cells.
[1]. H. Schillersa, I. Medalsyb, S. Hub, A. L. Sladeb and J. E. Sha

 

[267] SYNTHETIC GENE CIRCUITS INTEGRATED ON A CHIP

 

Alexandra Tayar1, Eyal Karzbrun2

1 Weizmann Institute of Science; M&i Perlamann 414
2 Weizmann Institute of Science; Department of Molecular Genetics

Synthetic gene circuits integrated on a chip

Alexandra M. Tayar1, Eyal Karzbrun1, Vincent Noireaux2, Roy H. Bar-Ziv1, 3
1Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, Israel, 76100
2Department of Physics, University of Minnesota, Minneapolis, Minnesota, 55455, USA

Abstract

Gene circuits regulate fundamental cellular functions, from macroscopic spatiotemporal patterns in development to assembly of structures and machines at the nanoscale. Integration of synthetic transcription-translation circuits into solid-state devices, with control of local RNA and protein synthesis, would enable programmable devices and assembly lines for applications in nanobiotechnology. We created a diffusive system of confined localized gene expression sources and sinks, which drive the emergence of rich dynamic states of patterned gene circuits. Proteins are synthesized from crowded DNA brushes (source) patterned in silicon-fabricated 2D compartments about a micron deep. Steep steady-state linear protein concentration gradients form along a capillary connecting the DNA compartments to a flow reservoir (sink). We observe steady-state expression, pulses, and oscillations, with protein levels and period times linear in the capillary length, thereby establishing a geometric means to regulate circuits in the device. Transcription regulation in the 100nm thick DNA brush is directly observed in real-time. More than 80 circuits were integrated in a single device, which in principle could be scaled up to thousands of micron-size compartments using current fabrication techniques1,2.

1. Karzbrun E, Tayar AM, Noireaux V, Bar-Ziv RH. Programmable on-chip DNA compartments as artificial cells. Science. 2014;345(6198):829–832. doi:10.1126/science.1255550.

2. Tayar AM, Karzbrun E, Noireaux V, Bar-Ziv RH. Propagating gene expression fronts in a one-dimensional coupled system of artificial cells. Nat Phys. 2015;advance on. doi:10.1038/nphys3469.

 

[278] LIGHT ACTIVATED HYBRID NANOPARTICLES FOR BIO-MEDICAL APPLICATIONS

 

nir waiskopf1, Yuval Ben Shahar2, Hermona Soreq3, Uri Banin4

1 Institute of Chemistry and the Center for Nanoscience and Nanotechnology; Dept. of Biological Chemistry, The Hebrew University of Jerusalem
2 The Institute of Chemistry and Center for Nanoscience and Nanotechnology; The Hebrew University of Jerusalem
3 Dept. of Biological Chemistry; The Hebrew University of Jerusalem
4 Institute of Chemistry and the Center for Nanoscience and Nanotechnology; The Hebrew University of Jerusalem

Hydrogen peroxide (H2O2) can cause significant damage in biological systems, culminating in cell death. However, local and tunable control of H2O2 production can be of utmost importance. For example, the enzyme thyroid peroxidase uses H2O2 for the production of the thyroid hormones. Its depletion leads to hypothyroidism, resulting in fatigue, joint and muscle pain, depression and more. At the translational research level, horseradish peroxidase (HRP) and hydrogen peroxide are employed in many detection and quantification methods where the introduction of hydrogen peroxide at high spatial-temporal resolution offers an added value.
Recent developments and progress in the synthesis of semiconductor-metal hybrid nanoparticles (HNPs) allow unprecedented control over the composition and structural properties of these hybrid systems, promoting the ability to tune its chemical and physical characteristics. Such control opens new opportunities for utilizing HNPs in diverse applications. A unique synergistic property that arises from the semiconductor-metal interface is an efficient spatial charge separation. This results in efficient functioning and photo-catalysis in redox reactions, including hydrogen generation by water splitting, and photo-degradation of organic contaminants.
Here we present HNP-mediated formation of radicals and peroxides amenable for use in the controlled local modulation of biological systems, with important research and bio-medical utilities. As a model system we show potentiation of HRP activity and inhibition of cholinesterase activities by light stimulation of CdSe/CdS-Au HNPs, as well as the option to add supportive enzymes (e.g superoxide dismutase (SOD)) or molecules (hole acceptors) which increase the efficiency and specificity of the system. We further demonstrate the advantages in the use of HNPs over bare semiconductor nanoparticles and the context-dependence of these capacities on the HNP properties.
The ability to control radicals and peroxides formation in a high spatio–temporal manner using HNPs excitation can deepen our understanding of the corresponding biological processes, improve the available tools for light modulation of enzymatic activities and open new avenues for developing novel treatments for diverse diseases.

 

[417] PEPTIDE INDUCED PLASMONIC CIRCULAR DICHROISM AS A SENSITIVE PROBE OF PEPTIDE CONFORMATION

 

Tatyana Levi Belenkova1, Gil Markovich2

1 School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences; Tel Aviv University
2 School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences; Tel-Aviv University

Chirality is an important theme in bio-molecular and organic chemistry due to its key role played in biological processes and in determining pharmacological, pharmacokinetic and toxic features of various molecules. When bio-molecules are assembled on metal nanostructures they can impart optical activity to the nanomaterial in the form of plasmonic circular dichroism (CD) signal in the visible spectral region.
In our study we explore plasmonic CD signal induced by short polyproline peptides adsorbed to silver nanocubes (NCs). Interestingly, the CD induction occurs for one specific plasmon resonance mode and not in other modes. We show that the plasmonic CD signal inverts its polarity when the adsorbed molecule orientation is inverted. This is due to a change in the orientation of transition dipole moments of chromophores in the peptide chain (mainly carbonyl groups) with respect to the metal surface.
This work demonstrates that CD induction by chiral molecules in noble metal nanostructures with well defined geometries may be used as a sensitive conformational probe and provide information about the adsorbed configuration of the molecules. Such molecule-NC assemblies might be useful for chiral separations.

 

[431] EXCITON SUPER TRANSFER IN BIOLOGICAL NANO-WIRES

 

Ido Eisenberg1

1 Hebrew University; Hebrew University

Exciton super transfer in biological nano-wires
Antenna complexes of photosynthetic cyanobacteria poses superior excitation transfer efficiency at room temperature. In this study we explored how to control and use these properties in order to get an efficient nano to micro scale energy transmission. The energy transfer is examined using Phycocyanin trimers that are modified and dried on several substrates. Results show ordering of the proteins using two different methods. One method is adding salts to the solution which makes them arranged in orthogonal dendrites. The second method is filling micro-trenches by spin-coating. Using this method we achieve bundles of nano-wires of Phycocyanin. We believe that during the drying process the proteins arrange in super-molecular organizations mimicking the native proteins. Optical measurements indicate large distance of ~1μm size excitation transport mechanisms. Time resolved measurements show that organized structures exhibit shorter exciton life-time than native proteins. Such structures may serve as a nano-metric energy transmission lines, and may be used to couple light to nano-devices.

 

[432] SINGLE MOLECULE FLUORESCENT ASSAY FOR QUANTIFICATION OF DNA TANDEM REPEATS

 

assaf grunwald1

1 Tau; School for Chemistry

SINGLE MOLECULE FLUORESCENT ASSAY FOR QUANTIFICATION OF DNA TANDEM REPEATS
Assaf Grunwald a, , ElmarWeinhold b, Fredrik Westerlund C, Yuval Ebenstein a
aDepartment of Chemical Physics, School of Chemistry, Tel Aviv University, Tel Aviv, Israel, bInstitute of Organic Chemistry, RWTH Aachen University, Aachen, German ,cDepartment of Chemical and Biological Engineering, Chalmers University of Technology, Goteborg, Sweden
yebenstein@gmail.com
Studies and quantification of DNA repetitive elements is a major stumbling block for next generation sequencing methods, due to difficulties in assembly of identical short reads. Other methods used today to assess repeats offer relative, averaged and inaccurate results. Thus, these regions, which occupy almost 50% of the human genome(ref), are still poorly characterized. Accurate quantification of genetic repeat regions is especially important for the diagnosis of some genetic disease, characterized by an impaired number of DNA repeat units, such as FSHD, the third most common muscular dystrophy.
Optical mapping of DNA enables direct visualization of individually stretched DNA molecules. DNA stretching is enabled by forcing it into a nano-channels array using an electric field. This concept can be harnessed for repeat quantification if a distinct fluorescent signal could be encoded on each repeat unit, allowing direct physical counting of repeats.
We applied this approach to characterize BAC DNA containing the FSHD disease associated repeat array, and its surrounding DNA region. The DNA methyltransferase M.TaqI was used to generate a single fluorescent label on each repeat unit, enabling direct quantification of the repeat array. The same labeling reaction generates a specific labeling pattern on the DNA sequence surrounding the repeat, allowing its identification by measurement of the fluorescent amplitude modulations along the stretched DNA and using cross correlation analysis between the experimental and theoretical fluorescent modulation plots.
We demonstrate initial results towards establishing this assay as a clinical platform for FSHD studies. This would allow rapid detection, from relatively low amounts of DNA, hopefully enabling efficient diagnosis and studies of the disease.

 

[450] TUNING CHEMILUMINESCENCE OF A LUMINOL FLOW BY PLASMONIC NANOPARTICLES

 

Alina Karabchevsky1, Ali Mosayyebi2, Alexey Kavokin3

1 Ben-Gurion University of the Negev; 84105
2 2optoelectronics Research Centre University of Southampton; University of Southampton
3 3department of Physics and Astronomy, University of Southampton, So17 1bj; Spin Optics Laboratory, St-Petersburg State University, 1, Ulianovskaya, 198504

Chemiluminescence is a fascinating optical effect that finds its use in various application areas: from forensic science to industrial bio-chemistry. Luminol is a chemical that exhibits chemiluminescence with emitted blue glow light. About five decades ago, luminol was used, for the first time, to analyze a crime scene in Germany. Since then, it became a very popular tool of criminology as it allows for revealing blood stains. We discover a giant increase of the intensity of chemiluminescence of a luminol flow (Figure 1) and a dramatic modification of its spectral shape in the presence of metallic nanoparticles [1]. We observed that pumping gold and silver nanoparticles into a microfluidic device fabricated in polydimethylsiloxane prolongs the glow time of luminol. We demonstrate that the intensity of chemiluminescence in the presence of nanospheres is dependent on the position along the microfluidic serpentine channel. We show that the enhancement factor can be controlled by the nanoparticle size and material. Spectrally, emission peak of luminol overlaps with the absorption band of nanospheres (Figure 1). This maximizes the effect of confined plasmons on the optical density of states in the vicinity of the luminol emission peak. This observations interpreted in terms of the Purcell effect mediated by nano-plasmons is an essential step toward the development of microfluidic chips with gain media. Practical implementation of the discovered effect includes improving detection limits of chemiluminescence for the forensic science, research in biology and chemistry, and for a number of commercial applications.

Figure 1 (a) Experimental images of the studied serpentine taken by a CCD camera. Luminol has been injected with the flow rate of 0.35 L/sec with silver nanoparticles of rSNP=30nm (left) to be compared with reference signal detected in the absence of nanoparticles (right). (b) Intensity over a cross section of images shown in (a). Serpentine arms under investigation are labeled by roman numerals. Note: the subscript SNP abbreviates silver nanoparticles.

 

[479] ASSEMBLY OF SILK-CBD NANOFIBERS, MIMICKING SPIDER SILK HIERARCHICAL STRUCTURE

 

zvi shtein1, Oded Shoseyov1

1 The Hebrew University of Jerusalem; Robert H. Smith Faculty of Agriculture, Food and the Environment

Assembly of Silk-CBD Nanofibers, Mimicking Spider Silk
Hierarchical Structure
Biopolymer research has focused in recent years on fibrous proteins due to their unique mechanical properties. Examples include collagen, elastin, silk worm silk, spider dragline silk and resilin. These proteins are distinguished by their repetitive amino acid sequences that confer impressive mechanical properties, such as strength and flexibility.
Spider silk proteins form intrinsic composites dictated from their unique molecular structure that combine highly crystalline domains embedded in amorphous domains resulting in fibers that combine strength and elasticity. In spite of the attractive mechanical properties of silk fibers, spiders produce silk in small quantities, and their territorial behavior prevents large amounts from being raised for farming silk. Consequently isolation of large amounts of silk from spiders is not feasible and these materials must be produced by recombinant protein technologies.
In the present study, we examined the hypothesis that the dimerization of cellulose binding domain (CBD) can direct the ordered assembly of silk proteins into supermolecular fibrillar structures. Nanofiber formation, in the absence of the nonrepetitive N and C termini, is possible due to the novel cellulose binding capability of the recombinant silk-CBD protein.
The fusion spider silk-CBD gene, consists of a synthetic 15 monomer long spider silk gene based on a monomer consensus derived from the native sequence of MaSp1 of Nephila clavipes fused to the 5′ of family III CBD originated from Clostridium cellulovorans, was successfully expressed in E.coli and purified on Ni-NTA under native conditions. Based on the silk-CBD assembly model, suggesting CBD induces spider silk molecular order and can function as the non-repetitive C-termini of MaSp1 protein, we further investigated the ability of CBD to form dimers which is thought to give molecular alignment to silk proteins in the nanofiber formation process. We show that sonication and buffer conditions encourages the self-assembly of nanofibers.

 

[489] PROGRAMMABLE SELF-ASSEMBLY OF PROTEIN NANO MACHINES ON SILICON CHIPS

 

Ohad Vonshak1, Shirley Daube1, Roy Bar-Ziv1

1 Weizmann Institute of Science; Department of Materials and Interfaces

Programmable self-assembly of protein nano machines on silicon chips
Ohad Vonshak, Shirley S. Daube, Roy H. Bar-Ziv
Department of Materials and Interfaces
Weizmann Institute of Science
The bottom up design and fabrication of man-made self-assembled machines at the nano scale could be advanced by looking for inspirations in nature. Biological systems operate as an intricate network of association and dissociation reactions run by large macromolecular machines. From structural assemblies that serve as vehicles of genetic materials such as T4 bacteriophage (figure), to multi protein RNA complexes that catalyze complicated biochemical reactions such as the ribosome, these biological nano-machines are self-assembled in vivo in an orchestrated assembly line, avoiding non-specific interactions with thousands of surrounding cytoplasmic proteins and RNA molecules. Could we delineate key mechanistic steps that are required to realize specific, reproducible and efficient nano-machine self-assembly?
Towards mimicking in vitro self-assembly of biological nano-machines, we have devised a methodology to synthesize in cell-free extracts protein and RNA molecules on a silicon chip (figure). The chip can be programed in space and time to dictate assembly of the protein and RNA building blocks in to macromolecular nano-machines. We are using surface-bound genes as the source of assembly components and antibody traps as the localization site for assembled complexes. In a multi-well silicon chip, the surface is patterned by UV light to spatially resolve genes and traps, each well with its own pattern. The genetic program in each well specifies which proteins would be destined to fluorescent labeling or for antibody trapping, respectively. Preliminary results demonstrate that proteins can be synthesized in a cell-free extract and reproducibly form specific multi-protein complexes on the silicon chip. Significantly, assembly outcome may be tunable by the relative geometrical arrangement of genes and traps.

 

[499] NANOCHANNEL ARRAYS FOR EPIGENETIC MAPPING OF HUMAN CHROMOSOMES

 

Tslil Gabrieli1, Yuval Ebenstein2

1 Tel Aviv University; Tel Aviv University
2 School of Chemistry; Tel Aviv University

NANOCHANNEL ARRAYS FOR
EPIGENETIC MAPPING OF HUMAN CHROMOSOMES

Tslil Gabrieli, Yael Michaeli, Tamar Shahal, Hila Sharim, Yuval Ebenstein

5-hydroxymethyl-cytosine (5hmC) is a recently rediscovered epigenetic modification of DNA with tissue and cell type specific distribution in mammalian genomes. Recent studies of genomic DNA, found that a substantial fraction of 5-methyl-cytosine (5mC) in CpG dinucleotides is converted to 5hmC and is mainly abundant in the central nerves system. The dynamic nature of this modification implies that 5hmC patterns may exhibit a high degree of cell to cell variation and should be studied by single-cell or single-molecule analysis. We have recently developed a method for optical detection of the epigenetic modification 5hmC at the single-molecule level. We use a chemo-enzymatic reaction to covalently attach a fluorescent reporter molecule to 5hmC nucleotides. Labeled DNA is electrokinetically squeezed into an array of silicon nanochannels and imaged on a fluorescence microscope. This nanochannels array has two entrance points in which the tangled DNA can enter, by high electrical force. The molecules enter to wide nanochannels and are then forced to straighten by nano-pillars which are positioned in the entrance to the narrow nanochannels.
5hmC residues are visible as fluorescent spots along the DNA contour. The human genomic DNA was labeled with an additional color at specific sequence motifs (GCTCTTC) to generate a locus specific pattern of dots that can be used in order to map the molecule onto the reference genome. We show first results of single-molecule epigenetic mapping of chromosomal DNA extracted from human peripheral blood cells. DNA molecules typically spanning several hundred Kbp (and up to 2Mbp) were visualized in the channels.

 

[501] THE INTERMOLECULAR FORCES THAT GOVERN THE FORMATION OF AMYLOID-LIKE FIBERS IN A BACTERIAL BIOFILM

 

razan abbasi1

1 Hebrew University of Jerusalem; Givat Ram

Razan Abbasi and Liraz Chai
The School of Chemistry, The Hebrew University of Jerusalem
A biofilm is a group of microorganisms in which cells stick to each other on a surface. Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial and hospital settings. The cells in a biofilm are embedded within a self-produced matrix of extracellular polymeric substance (EPS). The EPS is generally composed of extracellular DNA, proteins and polysaccharides. In biofilms of our model organism, the soil bacterium Bacillus subtilis, cells are held together by extracellular cell-anchored amyloid-like fibers that are composed primarily of the protein TasA. TasA has an accessory protein, TapA, that serves both to anchor the fibers to the cell wall and to assemble TasA into fibers. Despite the knowledge of the location of TapA in the biofilm, little is known about the mechanism of action of this protein. In particular, we are interested in studying the TapA-TasA and the TapA – cell surface interactions in order to better understand the role of TapA in the formation of the amyloid-like fibers. A molecular understanding of the assembly of the amyloid-like fibers may lead the way to developing new anti-biofilm drugs.

 

[522] SILICON NANOWIRES ARRAY FOR MONITORING OF BCTERIAL BIOFILM METABOLIC ACTIVITY

 

Ella Davidi1, Vadim Krivitsky1, Marina Zverzhinetsky1, Fernando Patolsky1

1 School of Chemistry; School of Chemistry

Silicon Nanowires Array for Monitoring of Bcterial Biofilm Metabolic Activity
Abstract
Bacterial biofilms cause severe infections, which are usually difficult to remove without invasive surgery. Cell metabolism, and in particular glucose metabolism, has been shown to reflect the state of living cells and microorganisms. Our goal is to investigate metabolic activity of biofilms in real time, in order to adjust the proper medical treatment to overcome biofilm infection. We created a platform that enables monitoring the metabolic activity of biofilms based on glucose consumption and other metabolites secretion. Monitoring the metabolic activity of biofilms, could help us finding effective treatment approaches. Here we present a series of experiments, monitoring in real time the Bacillus Subtilis biofilm metabolic activity. The metabolic activity of cells has been researched and monitored in our lab, using silicon nanowires (SiNWs) arrays, configured as a field-effect transistor (FET), that enable real time, label-free detection of biological species. We used surface modification on SiNWs FET, to generate a monolayer of the electroactive 9,10-dihydroxyathracene species, in order to perform direct sensing of glucose. We have managed to monitor the metabolic pathway of Bacillus Subtilis Biofilms from glutamate and glycerol consumption to glucose consumption. In addition, we managed to track the glucose consumption during several repetitive cycles. These results support the novel application of these biosensors for real time monitoring of bio-samples, for both clinical and environmental applications.

 

Proton conduction in self-assembled Amyloid β peptide fibrils: the effect of peptide side chains.

 

Ohad Silberbush1, Moran Amit1 and Prof. Nurit Ashkenasy1, 2
1. Department of Materials Engineering, Ben Gurion University of the Negev, Beer- Sheva, Israel
2. The Ilse Katz Institute for Nanoscale Science & Technology, Ben Gurion University of the Negev, Beer- Sheva, Israel
Abstract:
The chemical diversity, ease of synthesis, and self-assembly propensity of peptides make them attractive materials for bioelectronics applications. Taking example from nature, conduction in such bio mimetic materials could be facilitated either by electrons, protons or both. In particular, the presence of hydrogen donating and accepting groups, such as carboxylic acid and amino groups, at the peptide side chains may facilitate affective proton conduction. Aiming at revealing the effect of such side chains on the unexplored proton conduction of self-assembling peptide nanostructures, we present here a systematic study that examines the dependence of protonic conductance on peptide side chains in amyloid β- based peptide fibers.
The peptides used in this work are mutations of the core sequence of the amyloid β protein, AAKLVFF and AAELVFF, with amine and carboxylic acid side chain residue at the third amino acid in the sequence, respectively. The self-assembly of the peptides into fibrous nanostructures with a varying diameter is verified using atomic force microscopy and scanning electron microscopy. Current-voltage measurements reveal an exponential dependence of the conductance on the relative humidity, as expected for proton conduction. Moreover, the conductance was found to be higher for AAELVFF peptide assemblies than for AAKLVFF assembly at each of the measured relative humidity conditions. This behavior is related to the higher mobility of protons (H+) vs. proton holes (OH-). Our findings demonstrate that protonic conduction may be tuned by a proper peptide sequence design. The ability to generate both proton and proton holes may lay the ground to proton based switches and transistor devices.

 

Steering Committee

Scientific Committee

 

Prof. Ernesto Joselevich, Weizmann Institute of Science, Israel

Prof. Reshef Tenne, Weizmann Institute of Science, Israel

Prof. Uriel Levy, The Hebrew University of Jerusalem, Israel

Prof. Yuval Golan, Ben Gurion University, Israel  

Prof. Yuval Garini, Bar Ilan University, Israel

Prof. Yael Hanein, Tel Aviv University, Israel  

Prof. Gadi Eisenstein, Technion, Israel

Mr. Rafi Koriat, Israel National Nanotechnology Initiative, Israel  

Mr. Haim Rousso, Elbit, Israel  

Prof. Uri Sivan, Technion, Israel  

Prof. Ori Cheshnovsky, Tel Aviv University, Israel

Prof. Rimona Margalit ,Tel Aviv University, Israel

 

Steering Committee

 

Ms. Shoshi Caspi, Matimop, Israel

Prof. Ori Cheshnovsky, Tel Aviv University, Israel

Prof. Gadi Eisenstein, Technion, Israel

Prof. Yuval Garini, Bar Ilan University, Israel

Prof. Yuval Golan, Ben Gurion University, Israel    

Prof. Yael Hanein, Tel Aviv University, Israel    

Mr. Michel Hivert, Matimop, Israel    

Prof. Ernesto Joselevich, Weizmann Institute of Science, Israel

Mr. Rafi Koriat, Israel National Nanotechnology Initiative, Israel    

Prof. Uriel Levy, The Hebrew University of Jerusalem, Israel

Mr. Oren Regev, Kenes Exhibitions, Israel    

Mr. Haim Rousso, Elbit, Israel    

Ms. Michal Shenhar, Tel Aviv University, Israel    

Prof Uri Sivan, Technion, Israel    

Dr. Ehud Galun ,MAFAT, Israel

Mr. Dan Vilenski, Israel National Nanotechnology Initiative, Israel    

Mrs. Prema Zilberman, Kenes Exhibitions, Israel

Ms. Lyne An, Kenes Exhibitions, Israel

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