January 15th, 2015

ctors' message: 

Over the fall and early winter, we had several fruitful meetings including the annual UW AMIC meeting last fall with record turnout (feedback is still welcome!), speed networking and research descriptions oriented for broader spectrum audiences; the Breakthroughs in Research and Education Workshop (BREW) with a more fundamental focus on research and its translation to educational activities; Wisconsin Materials Science and Engineering Affiliates (WIMSEA) which highlighted the industry sponsored senior capstone projects for materials science undergraduates and a tour of the new collaborative and teaching facilities which includes a new Hysitron nano-indenter (more details below); and we attended several manufacturing conferences as well as the Digital Manufacturing and Design Innovation Institute (DMDII) kickoff meeting in Milwaukee.  


We made site visits to Xolve (technology: chemical nanomaterial (graphene) dispersal process), Imbed Biosciences (technologies: antibacterial, antibiofilm and analgesic wound dressing films), Platypus Technologies (liquid crystal chemical sensors and precision gold coatings), Sector67 (hacker/maker space) and Midwest Prototyping (additive and traditional manufacturing center), learning more about their products, their questions and how we can connect them to the resources of the University of Wisconsin-Madison.


This is an exciting time for advanced materials research, education and industry in Wisconsin. Federal, state, academic and industry stakeholders are committed to executing the goals of the Strategic Plan of the Materials Genome Initiative:


1)     Leading a culture shift in materials-science research to encourage and facilitate an integrated team approach;


2)     Integrating experiment, computation, and theory and equipping the materials community with advanced tools and techniques;


3)     Making digital data accessible; and


4)     Creating a world-class materials-science and engineering workforce that is trained for careers in academia or industry.


Over the last several months we have been networking with partners, both on- and off-campus and within state agencies, to synergize efforts to interconnect advanced materials- and manufacturing-oriented groups at several UW System campuses. We are partnering with the Wisconsin Materials Institute (WMI) as WMI develops a Regional Materials and Manufacturing Network (RMMN).  


The heart of this effort is an online portal (wiscmat.org) to materials development resources, expertise, and equipment available within the University of Wisconsin System. As part of this effort, RMMN member schools will join with their industry partners to form a Regional Industrial Network (RIN) to facilitate Industrial collaborations with UW System materials development resources to solve materials problems. 


Collaborative interactions will vary according to RMMN member campus policies, but will take advantage of local expertise and connection in each local area throughout the state, with benefits modeled loosely on UW Madison's AMIC. UW AMIC is the first member of the RIN, and is working closely with WMI to build the RIN. The motivations behind this are to foster a more collaborative network which will tend to naturally form a technology pipeline - connecting fundamental researchers with researchers that focus on problems found in current Industrial materials engineering needs and manufacturing practice, by partnering with regional manufacturers, and accelerating the development of scalable and manufacturable products and processes.


On a more grassroots level, we have been talking to and getting to better know the entrepreneurs in our backyard through meetings and site visits (let us know if you want to arrange a call, meeting or site visit!). Through this, the tapestry of the local technology and business landscape becomes more complete allowing us to make and facilitate better connections to help you solve your materials issues. As always, if you have questions, suggestions or comments, please let us know!



Best regards,


Felix Lu and Erin Gill,

Co-Directors, UW AMIC




Visit to UW Stout Plastics Engineering Laboratory with (L-R) Prof. Wei Zhang, Dr. Erin Gill, Prof. Elizabeth Glogowski (UW Eau Claire), Dr. Felix Lu

Prof. Adam Kramschuster (UW Stout) leading the tour of the Plastics Engineering Laboratory at UW Stout.


Prof. Mike Zach at UW Stevens Point demonstrating his desktop setup for depositing and transferring molded nanostructures.
New Director of Research Shared Instrument Facilities hired

Dr. Jerry Hunter

New Director of Research Shared Instrument Facilities for the College of Engineering

After the former director, Dr. Jon McCarthy retired last summer, Dr. Jerry Hunter was recently announced as the new director.   Jerry was most recently a research assistant professor, and adjunct professor in the departments of materials science and engineering and geosciences at Virginia Tech University, working mainly with SIMS and XPS instruments along with research and proposal development. Previous appointments he has held include senior consultant and specialist at Evans Analytical Group, Western regional manager for Materials Analytical Services,  VP of Operations and Engineering, and Director of Materials Analysis at Accurel Systems, Surface Analysis Area Manager at Intel Corp., SIMS Analyst at Phillips Corp., and a post doctoral Researcher at North Carolina State University. He received in PhD. from the University of North Carolina at Chapel Hill in Chemistry.

Jerry started in his position at the UW Madison College of Engineering in mid-November and will be responsible for managing all business aspects of the core facilities, which include the Materials Science Center, the Wisconsin Center for Applied Microelectronics and the Soft Materials Laboratory.

He can be reached at:  jhunter5@wisc.edu and 608-263-1073, and his office is 272 Materials Science and Engineering Building (MSE).

AMIC Partner Groups
Are you confused by the array of different groups on campus for helping local industry? Here is a consolidated list with explanations and descriptions that may help:

AMIC - Advanced Materials Industrial Consortium (http://uwamic.wisc.edu) - the industrial outreach branch of the NSF funded MRSEC at UW Madison. We continually seek to engage or re-engage local and regional industry by marketing our materials characterization and processing resources, offering : targeted student recruitment, facilitated meetings with faculty and other subject matter experts, and serve as a liaison between companies and the university centered around materials science issues. Ask us about anything though and we will redirect you to the appropriate resource.

CTC - Center for Technology Commercialization (http://www.wenportal.org) - the people at the CTC are a branch of the Division of Entrpreneurship and economic development under the UW Extension. They are veterans of the startup process which includes proposal writing, securing funding, business infrastructure development, and management issues. Their services are provided free towards the economic and industrial development for the state of Wisconsin.

OCR - Office of Corporate Relations  (http://ocr.wisc.edu) - OCR serves as a general point of contact between the university and the business world. They initiate all administrative processes, and redirect customers to the appropriate offices within the university for specific matters.

OIP - Office of Industrial Partnerships (http://research.wisc.edu/projectagreementsip/oip/)- OIP provides institutional review and negotiation of agreements and serves as a point of contact for UW investigators and industry partners.  They offer a flexible and individualized approach to establish industry partnerships while upholding the university's missions related to education, research, and public service.

WMI / RMMN (RM2N) - The Wisconsin Materials Institute / the Regional Materials and Manufacturing Network  (previously also known as the Regional Materials Network (RMN)) (http://wiscmat.org/) - is a group of materials scientists and engineers who are establishing regional connections to make a pipeline of resources to help speed up the discovery to product process. The WMI is the campus partner institute to the Materials Genome Initiative, which is about building and enhancing a materials science, engineering and manufacturing infrastructure to accelerate commercialization of new materials and products.

WIMSEA - The Wisconsin Idea - Materials Science and Engineering Affiliates  (http://sites.google.wisc.edu/wisconsin-idea-mse-affil/ )- is another way for local industry to be involved in the educational process while getting some insight on materials issues that they may be dealing with. The event is focused on small sponsored capstone research projects that students work on with faculty supervision.

IIP - International Industrial Program (http://internships.international.wisc.edu) IIP helps provide structured work placements related to students' academic studies.  For University of Wisconsin students exploring career options, IIP is a starting point  to find information and offers advising about working in the global economy and help them understand and overcome some of the barriers of international work assignments.

UW EXTENSION - Wisconsin Idea outreach (http://www.uwex.edu)
The UW Extension is a program that extends the boundaries of the UW system so that the universities' resources can touch and provide opportunities thoughout the state.

Then there are off campus groups that we also work with:

WMEP - Wisconsin Manufacturing Extension Partnership  (http://www.wmep.org) is a private, non-profit, consulting organization focused on the growth and success of wisconsin manufacturer.

WARF - Wisconsin Alumni Research Foundation (http://www.warf.org)

WARF is the private, nonprofit patent and licensing organization for the University of Wisconsin-Madison. WARF was founded in 1925 and is a pioneer and innovator among university-based technology transfer offices. WARF's mission is to support, aid and encourage UW-Madison research by protecting its discoveries and licensing them to commercial partners for beneficial use in the real world. It is best known for commercializing groundbreaking vitamin D therapies, the revolutionary anticoagulant Coumadin�, innovative medical imaging and cancer radiation systems, and its patents for human embryonic stem cells.



Wisys -(http://www.wisys.org) the patent and licensing organization for all the other UW universities except UW Milwaukee. WiSys Technology Foundation extends the mission, goals and objectives of its affiliate, the Wisconsin Alumni Research Foundation, to benefit 11 four-year campuses and 13 two-year colleges of the University of Wisconsin System. WiSys also serves UW-Extension.

WEDC - Wisconsin Economic Development Corporation (http://inwisconsin.com) - public-private corporation (created 2011) to replace the Wisconsin chamber of Commerce.

WEDA - Wisconsin Economic Development Association (http://www.weda.org) Lobbying group

WEDI - Wisconsin Economic Development Institute (http://www.wi-edi.org)  - "is a non-profit, non-partisan, foundation formed to conduct research and education designed to increase the effectiveness of the economic development efforts."

Still confused? Inaccurate? Not correct? Let us know what needs correction or clarification!

Recent patent filings from WARF and WYSIS

Recent selected materials related patent filings

New Amphiphiles for Manipulating Membrane Proteins
(INVENTORS - Samuel Gellman, Pil Seok Chae)

Superabsorbent, Sustainable Aerogels
(INVENTORS - Shaoqin Gong, Zhiyong Cai, Qifeng Zheng)

Thermogel for Combination Drug Delivery
(INVENTORS - Glen Kwon, Hyunah Cho)

New Method of Constructing a Quantum Cascade Laser with Improved Device Performance
(INVENTORS - Luke Mawst, Thomas Kuech, Jeremy Kirch)

Environmentally Green Glue
(INVENTORS - Srinivasan Damodaran, Dani Zhu)

Low-Temperature, Corrosion-Resistant Integrated Metal Coatings to Improve Efficiency of Coal Plants
(INVENTORS - John Perepezko, Ridwan Sakidja)

Water Purification Membranes Bearing Antimicrobial Polymers (INVENTORS - Samuel Gellman, Roni Kasher, Shannon Stahl, Jihua Zhang)

Nanoporous Insulating Oxide Deionization Device for Softening and Treating Water
(INVENTORS - Marc Anderson, Kevin Leonard)

Atmospheric Growth of Vertically Oriented Graphene
(INVENTORS - Junhong Chen, Kehan Yu, Zheng Bo, Ganhua Lu)

Electrochemical Capacitor/Battery Energy Storage Device Capable of Self-Charging
(INVENTORS - Marc Anderson, Kevin Leonard, M. Isabel Tejedor-Anderson)

Cleavable, Water-Soluble Surfactants
(INVENTORS - Nicholas Abbott, Lana Iva Jong)

Smoother Surfaces with Pulsed Laser Polishing
(INVENTORS - Frank Pfefferkorn, Xiaochun Li, Neil Duffie, Chao Ma, Venkata Madhukanth Vadali)
Have an area that you would like us to focus on?  
Please let us know!

Upcoming conferences & seminars 

Sponsored by the Wisconsin Manufacturing Extension Partnership (WMEP), the conference focuses on delivering unmatched opportunities for learning, networking, and collaboration. For 18 years the conference has focused attention on innovative practices that place Wisconsin Manufacturers among the very best in the nation.

Thursday, February 26th 2015

7:00 am - 4:15 pm

Hyatt Regency Milwaukee

333 West Kilbourn Avenue Milwaukee, WI 53203


Pittcon is the world's largest annual conference and exposition for laboratory science.
This dynamic global event offers a unique opportunity to get a hands-on look at the latest innovations and to find solutions to your all laboratory challenges. The robust technical program offers the latest research in more than 2,000 technical presentations covering a diverse selection of methodologies and applications. Pittcon also offers more than 100 short courses in a wide range of topics and the once-a-year chance to network with colleagues.

March 8 - 12, 2015
Ernest N. Morial Convention Center
New Orleans, LA USA

The 2015 MRS Spring Meeting and Exhibit will be held in San Francisco, California. All technical sessions and non-technical events will be held at the Moscone West Convention Center, San Francisco Marriott Marquis and The Westin San Francisco Market Street. Locations and schedules of individual symposia will be posted in early 2015 as available. Non-technical events will be listed on the menu to the left. Information about individual sessions and special events will be posted as they become available closer to the meeting.

Spring 2015 National meeting & Expo
March 22-26, Denver, CO

Highlights from the Fall 2014 AMIC meeting

Thank you to those who participated in the 2014 annual AMIC meeting. We had a record turnout and a meeting packed with a variety of interesting speakers. Student and postdoctoral researchers gave a high level teasers of their research in the different MRSEC research thrusts, and then got some valuable face time with industry participants in a speed networking event.

We are already considering ideas and plans for next year's event! If you have any feedback on the 2014 meeting, you can email or call us or use an online form: http://survey.constantcontact.com/survey/a07e9wq98l3i0o4gaqe/a009i1auw937/questions

For more information, please contact Felix Lu or Erin Gill.

New instrumentation
 The Hysitron TI 950 TriboIndenter is the next generation nanomechanical test instrument providing industry-leading sensitivity and unprecedented performance. The TI 950 nano-indenter has been developed as an automated, high throughput instrument to support the numerous nanomechanical characterization techniques developed by Hysitron. The TI 950 nano-indenter system incorporates the newly developed performech� Advanced Control Module, which greatly improves the precision of feedback-controlled nanomechanical testing, provides dual head testing capability for nano/micro scale connectivity, and offers unprecedented noise floor performance. The numerous nanomechanical testing techniques currently offered, as well as new testing methods currently being developed, make the TI 950nano-indenter system an exceptionally versatile and effective nanomechanical characterization tool for the broadest range of applications.

Combine the TI 950 nano-indenter with Hysitron's xSol High Temperature Stage for quantitative, accurate, and reliable nanomechanical characterization at elevated temperatures up to 800 �C.

Integrated with low-noise three-plate capacitive transducers and electronics, the multi-layered enclosure and active vibration isolation system provide excellent environmental separation for the instrument.


The Hysitron nanoindenter resides in the Materials Science Center. Please contact Dr. Julie Last for training and access. 

Hysitron manufacturer's page

AMIC member spotlights


Jonathan McAnulty, chair of the Department of Surgical Sciences at the UW School of Veterinary Medicine, holds up a small portion of an ultra-thin, polymeric nanofilm containing nanoparticles of elemental silver that is used in advanced wound dressings. Research has demonstrated the ability of the nanofilm to speed up wound closure and reduce the need for painful and costly bandage changes. (Photo: Nik Hawkins)

Imbed Biosciences, Inc., a medical device start-up company that stems from research conducted at the University of Wisconsin-Madison, recently received a $1.5 million award to further test the effectiveness of ultrathin wound dressings that contain silver nanoparticles, a study that Professor Jonathan McAnulty  will lead at the UW School of Veterinary Medicine.

According to McAnulty, chair of the Department of Surgical Sciences and Imbed co-founder, the idea of silver as a disinfectant and healing aid goes back a long way.

"You've heard about people being born with silver spoons in their mouths," he says. "Back when food could be a little suspect, wealthier people had silver utensils and plates, and they probably had some kind of antimicrobial effect."

prepared, even with different protocols. This greatly reduces the chance for process errors and mix-ups, while also reducing costs." 

However, the use of microscopically small lumps of elemental silver, or nanoparticles, in wound dressings is a much newer concept, and its distinct advantages have gained it wide acceptance in the medical field.


 For example, although silver fights off infection by killing bacteria and fungi, it's not an antibiotic, so the human body tends to accept it more readily. In addition, unlike most silver products, which are ionized, elemental silver carries no charge. This slows the rate at which it is released into the wound, extending the period of its effectiveness as an antimicrobial agent. Research has shown that all of these attributes help speed up wound closure.


The truly novel part of these wound dressings, however, is that they house the silver nanoparticles in a porous, polymeric nanofilm that resembles dusky-hued cellophane and is made of a multilayer lattice of oppositely charged polyelectrolytes. "It's a super-fine, ultrathin membrane, potentially less than one cell thick." says McAnulty. "It allows the active agents, the nanoparticles, to attach on the cell surface, right where they need to be, rather than in the wound fluid. The nanoparticles in the film dissolve over time to provide sustained release of antimicrobial silver ions. The film ultimately disintegrates and exfoliates in wound debris."


This process creates several advantages. The localization of the material allows for lower concentrations of silver, which results in less toxicity for the cells in the wound and the patient, and the dissipation of the material reduces the need for wound dressing changes, which can be painful for patients and hospital budgets alike.


Imbed is currently looking for student interns to work over the semester and the summer months. Please contact Dr. Ankit Agarwal for details. 


Do you want to submit a member  spotlight for your company? Please contact Felix Lu (fplu@wisc.edu) for more details.

Recent faculty news
Trisha Andrew, a UW-Madison assistant professor of chemistry, holds a solar cell her research group printed on paper last year. Andrew was named a Packard Fellow this week in recognition of her work as an early career scientist.

Photo: Matt Wisniewski/Wisconsin Energy Institute


Trisha Andrew, a University of Wisconsin-Madison assistant professor of chemistry, is one of 18 early career scientists from around the country named a Packard Fellow for Science and Engineering.

The award includes a grant of $875,000 over five years to pursue research and is given in recognition of the potential significance of scholarship and innovation from the nation's most promising young scientists and engineers.

"The Packard Fellowships are an investment in an elite group of scientists and engineers who have demonstrated vision for the future of their fields and for the betterment of our society," said Lynn Orr, Keleen and Carlton Beal professor at Stanford University and chair of the Packard Fellowships Advisory Panel. "Through the Fellowships program, we are able to provide these talented individuals with the tools and resources they need to take risks, explore new frontiers and follow uncharted paths."


 Read more: http://www.news.wisc.edu/23211  




UW Materials Science in the news

University of Wisconsin-Madison chemistry professor  Shannon Stahl is one of five scientists nationwide to receive a Presidential Green Chemistry Challenge Award from the U.S. Environmental Protection Agency (EPA) in recognition of his research on using oxygen from the air in chemical reactions.

In the late 1990s, Stahl launched his investigation into so-called aerobic oxidations, which harness oxygen to synthesize chemicals in a way that minimizes the amount of waste created in the process. In 2007, Stahl's team began a two-year partnership with researchers at Eli Lilly and Company to test their methods in an industrial setting.

Soon after, the group began working with Professor of Chemical and Biological Engineering Thatcher Root to develop tools for adapting chemistry and engineering methods to industrial pharmaceutical settings. The two labs later expanded their collaboration to include a consortium of pharmaceutical companies, including Eli Lilly, Merck & Co. and Pfizer.



This lump of iron pyrite shows the characteristic cubic crystals of fool's gold. Defects in pyrite's crystal structure are an obstacle to building solar cells from the material.

Photo: UW-Madison Geology Museum


As the installation of photovoltaic solar cells continues to accelerate, scientists are looking for inexpensive materials beyond the traditional silicon that can efficiently convert sunlight into electricity.

Theoretically, iron pyrite - a cheap compound that makes a common mineral known as fool's gold - could do the job, but when it works at all, the conversion efficiency remains frustratingly low. Now, a University of Wisconsin-Madison research team explains why that is, in a discovery that suggests how improvements in this promising material could lead to inexpensive yet efficient solar cells.


UW Madison Chemistry Professor Song Jin 


"We think we now understand why pyrite hasn't worked," says  chemistry Professor Song Jin, "and that provides the hope, based on our understanding, for figuring out how to make it work. This could be even more difficult, but exciting and rewarding."

Although most commercial photovoltaic cells nowadays are based on silicon, the light-collecting film must be relatively thick and pure, which makes the production process costly and energy-intensive, says Jin.

A film of iron pyrite - a compound built of iron and sulfur atoms - could be 1,000 times thinner than silicon and still efficiently absorb sunlight.

Like silicon, iron and sulfur are common elements in the Earth's crust, so solar cells made of iron pyrite could have a significant

UW Madison Chemistry Graduate student and first author, Miguel Cab�n-Acevedo
material cost advantage in large scale deployment. In fact, previous research that balanced factors like theoretical efficiency, materials availability, and extraction cost put iron pyrite at the top of the list of candidates for low-cost and large-scale photovoltaic materials.



Journal link: http://pubs.acs.org/doi/abs/10.1021/nl2045364
Journal link: http://pubs.acs.org/doi/abs/10.1021/ja509142w


One major challenge currently facing the graphene industry is

Raman chemical image of island growth of monolayer graphene grown on Cu and transferred to SiO2/Si. The image, containing 10,000 spectra over a 50x50 micron area, was measured using 532-nm excitation at 3 mW with a collection rate of 100 spectra/sec and 10 co-addition scans. The total collection time was 16.7 minutes. 

difficulty in controlling the quality of graphene sheets when produced over large areas using industrial scale techniques. The key to solving this challenge lies in gaining a thorough understanding of the synthetic methods used to fabricate macro-sized single-layer graphene films. Raman imaging can be used to gain important insight with respect to critical parameters and mechanisms that govern the nucleation and growth of graphene via chemical vapor deposition (CVD).


One synthetic route starts with graphite and through exfoliation, single-layer graphene is obtained. This method yields high-quality graphene, but the number of graphene layers can't be controlled and the sample size is limited to tens of microns, making scalability unfeasible.

The other approach is when carbon precursors are converted into graphene on a catalyst surface. Here, methane is used as the precursor and copper as the catalyst. CVD typically occurs around 1,000 C, where carbon precursors adsorb on the catalyst surface and then decompose to form different carbon species serving as the fundamental building blocks during the graphene growth. These carbon species diffuse on the catalyst surface until they react with each other to form small carbon clusters. Once exceeding a critical size, graphene crystals nucleate.

As the deposition progresses, carbon species continue to add to the edges of the graphene islands, resulting in a continuous, single layer of graphene. Once a complete monolayer has formed, additional layers do not typically grow due to low reactivity of the graphene surface compared with that of the catalyst. Nucleation and growth are highly dependent on synthesis conditions, including growth temperature, pressure and precursor flux and composition, and catalyst properties, including the crystallinity, composition, crystal facet and surface roughness.

The deposition can be stopped prematurely to obtain information about the crystal growth. These partial-growth studies allow us to understand how the synthesis parameters affect the graphene crystal shape, orientation, crystallinity, nucleation density, defect density and evolution.

Scanning electron microscopy (SEM) illustrates the morphological characteristics that result from particular CVD deposition conditions; however, other techniques are required for deeper insight into the deposited graphene. For example, the Raman spectrum provides information on the number of graphene layers and about the density of defects incorporated into the graphene lattice during growth. Furthermore, spatial mapping reveals the graphene coverage, nucleation density and island morphology.

The Raman image was collected using 532-nm excitation and
Thermo Scientific Fast mapping Raman DXRxi used here is available for public use in the Soft Materials Laboratory
represents a total of 10,000 spectra over a 50-by-50-micron area and collected in under 17 min. With these specific growth conditions, graphene nucleation is inhomogeneous and the island shape is non-uniform. The Thermo Scientific DXRxi Raman imaging microscope software tools provide different views of the image including: correlation, which is intensity scaling against a known reference spectrum or a spectrum within the data acquired; intensity based on a peak height or area; intensity based on the peak height or area ratio of two peaks; intensity based on peak position and the statistical method Multivariate Curve Resolution (MCR).

NOTE: the Thermo Scientific DXRxi Raman is available for use in the Soft Materials Laboratory . Please contact Dr. Anna Kiyanova for more details on training and usage.



Fear of water may seem like an irrational hindrance to humans, but on a molecular level, it lends order to the world.

Some substances-lots of greasy, oily ones in particular-are hydrophobic. They have no attraction to water, and essentially appear repelled by the stuff.

Combine hydrophobic pieces in a molecule with parts that are instead attracted to water, and sides are taken. Structure appears, as in the membranes that encircle living cells.

"Those membranes are formed by molecules that are mostly greasy, and that pack together to avoid interacting with water," says Sam Gellman, a Univ. of Wisconsin-Madison chemistry professor. "The

Prof. Sam Gellman 

hydrophilic parts point in one direction-toward water-and the hydrophobic parts in the other, and the result is molecular organization that forms a wall."

And with it, all the things of life that require the wall's protection.

"It's arguably one of the most important interactions between molecules, because it occurs in water where biology and so much technology happens," says Nicholas Abbott, a UW-Madison chemical and biological engineering professor.

Abbott, Gellman and a group of Univ. of Wisconsin-Madison researchers have provided new insights on hydrophobic interactions within complex systems. In a study published in Nature, the researchers show how the nearby presence of polar (water-attracted, or hydrophilic) substances can change the way the nonpolar hydrophobic groups want to stick to each other.

The team built simple molecules with stable structures that incorporated hydrophobic and hydrophilic groups in precisely determined patterns. Then they used an atomic force microscope, a

Prof. Nicholas Abbott 

tool that allowed them to probe the surface of the molecules by tugging hydrophobic units apart and measuring the stickiness between them.

"We show that if you have two nonpolar groups, and they are going to interact through water, the way they interact depends on their neighbors," Abbott says. "It's just like a pair of friends having a conversation. The way in which they interact will depend on who is standing close enough to hear."

It's been theorized that the bonds between hydrophobic particles would indeed change in the presence of charged, water-loving molecules. The researchers' experiments demonstrated those effects, and noticed also that as the chemical structure of charged hydrophilic groups change, so does the magnitude of their impact on the stickiness between hydrophobic groups.


Link to the journal article:  http://www.nature.com/nature/journal/v517/n7534/full/nature14018.html 


Other Materials News
Flexible electronic sensors based on paper-an inexpensive material-have the potential to cut the price of a wide range of medical tools, from helpful robots to diagnostic tests. Scientists have now developed a fast, low-cost way of making these sensors by directly printing conductive ink on paper. They published their advance in ACS Applied Materials & Interfaces.

Anming Hu and colleagues point out that because paper is available worldwide at low cost, it makes an excellent surface for lightweight, foldable electronics that could be made and used nearly anywhere. Scientists have already fabricated paper-based point-of-care diagnostic tests and portable DNA detectors. But these require complicated and expensive manufacturing techniques. Silver nanowire ink, which is highly conductive and stable, offers a more practical solution. Hu's team wanted to develop a way to print it directly on paper to make a sensor that could respond to touch or specific molecules, such as glucose.

The researchers developed a system for printing a pattern of silver ink on paper within a few minutes and then hardening it with the light of a camera flash. The resulting device responded to touch even when curved, folded and unfolded 15 times, and rolled and unrolled 5,000 times. The team concluded their durable, lightweight sensor could serve as the basis for many useful applications.

Source: American Chemical Society 



A notothenioid fish in Antarctic ice. "Antifreeze" in its blood protects in the frigid waters. Image: Paul A. Cziko, University of Oregon
Antarctic fish that manufacture their own "antifreeze" proteins to survive in the icy Southern Ocean also suffer an unfortunate side effect, researchers funded by the National Science Foundation (NSF) report: The protein-bound ice crystals that accumulate inside their bodies resist melting even when temperatures warm.

"We discovered what appears to be an undesirable consequence of the evolution of antifreeze proteins in Antarctic notothenioid fish," said University of Oregon doctoral student Paul Cziko, who led the research with University of Illinois animal biology professors Chi-Hing "Christina" Cheng and Arthur DeVries. "What we found is that the antifreeze proteins also stop internal ice crystals from melting. That is, they are anti-melt proteins as well."

The new finding was reported in the Proceedings of the National Academy of Sciences.


Modified graphene aerogels have high surface area and excellent conductivity, and are promising for high-power electrical energy storage applications. Image: Ryan Chen
Personal electronics such as cell phones and laptops could get a boost from some of the lightest materials in the world.

Lawrence Livermore National Laboratory (LLNL) researchers have turned to graphene aerogel for enhanced electrical energy storage that eventually could be used to smooth out power fluctuations in the energy grid.

The team found that graphene aerogel-based supercapacitor electrodes could be particularly useful in the electric vehicle sector because they feature high surface area, good electrical conductivity, chemical inertness and long-term cycling stability.

Energy storage systems for electric vehicles have especially demanding requirements because they must combine high power and energy density, cyclability, safety and low cost. Supercapacitors (also known as ultracapacitors or electrical double-layer capacitors) can help to meet these requirements due to their high power density and excellent cycling stability.

"Commercial carbon-based supercapacitors are used to recover braking energy in numerous vehicles (cars, buses, trains, etc.) and to open the emergency exits of the Airbus A380," LLNL's Patrick Campbell said. "Our materials can potentially improve on the performance of these commercial supercapacitors by more than 100%."





Danish scientists have invented a revolutionary crystalline material that can absorb and store oxygen in high concentrations. A bucket of such material can suck the oxygen out of a room, which could potentially wave goodbye to heavy oxygen masks.

Imagine if you could get rid of the bulky scuba tank while taking a dive. Now, imagine practically any task to which the storage and timely release of oxygen is absolutely essential. And you have the new crystal developed at the University of Southern Denmark, with help from the University of Sydney, Australia.

A few microscopic grains are enough for one gulp of air, but a bucketful - or 10 liters - can completely suck the oxygen out of a room.

"In the lab, we saw how this material took up oxygen from the air around us," Professor Christine McKenzie, who led the study, said.

When different things are exposed to oxygen, they react differently - from wine to food to living organisms, varying factors (pressure, temperature etc.) and time of exposure can fundamentally alter things. However, what you get with the new discovery is a way of controlling oxygen by not reacting with it.

This was ascertained by using x-ray diffraction, showing the material's atomic behavior when it was full of oxygen, then when it was depleted of it.

"An important aspect of this new material is that it does not react irreversibly with oxygen - even though it absorbs oxygen in a so-called selective chemisorptive process. The material is both a sensor, and a container for oxygen - we can use it to bind, store and transport oxygen - like a solid artificial hemoglobin," McKenzie says.



The science of materials is one in which much progress is occurring and its application is virtually immediate. Perhaps its findings do not produce front-page news, but the impact of this discipline on our lives is significant, though not every discovery is very visible. By continually producing new materials with surprising properties or improving on materials known about for centuries, the products of these investigations end up being commonly used by all of us, almost without us noticing. Maybe soon we will see applications in our lives from these five recent inventions.

Structure for artificial diamond





ORNL researchers have demonstrated the ability to precisely control the structure and properties of 3-D printed metal parts during formation. The electron backscatter diffraction image shows variations in crystallographic orientation in a nickel-based component, achieved by controlling the 3-D printing process at the microscale.
Researchers at the U.S. Dept. of Energy (DOE)'s Oak Ridge National Laboratory (ORNL) have demonstrated an additive manufacturing method to control the structure and properties of metal components with precision unmatched by conventional manufacturing processes.

Ryan Dehoff, staff scientist and metal additive manufacturing lead at the DOE's Manufacturing Demonstration Facility at ORNL, presented the research in an invited presentation at the Materials Science & Technology 2014 conference.

"We can now control local material properties, which will change the future of how we engineer metallic components," Dehoff said. "This new manufacturing method takes us from reactive design to proactive design. It will help us make parts that are stronger, lighter and function better for more energy-efficient transportation and energy production applications such as cars and wind turbines."



Read more at: http://www.rdmag.com/news/2014/10/research-reveals-unique-capabilities-3-d-printing?et_cid=4211696&et_rid=614174443&location=top



Artist's impression of a comparison between a magnetic mirror with cube shaped resonators (left) and a standard metallic mirror (right). The incoming and outgoing electric field of light (shown as alternating red and white bands) illustrates that the magnetic mirror retains light's original signature while a standard metallic mirror reverses it upon reflection. Credit: S. Liu et al.
WASHINGTON, Oct. 16, 2014-As in Alice's journey through the looking-glass to Wonderland, mirrors in the real world can sometimes behave in surprising and unexpected ways, including a new class of mirror that works like no other.

As reported today in The Optical Society's (OSA) new high-impact journal Optica, scientists have demonstrated, for the first time, a new type of mirror that forgoes a familiar shiny metallic surface and instead reflects infrared light by using an unusual magnetic property of a non-metallic metamaterial.

By placing nanoscale antennas at or very near the surface of these so-called "magnetic mirrors," scientists are able to capture and harness electromagnetic radiation in ways that have tantalizing potential in new classes of chemical sensors, solar cells, lasers, and other optoelectronic devices.

"We have achieved a new milestone in magnetic mirror technology by experimentally demonstrating this remarkable behavior of light at infrared wavelengths. Our breakthrough comes from using a specially engineered, non-metallic surface studded with nanoscale resonators," said Michael Sinclair, co-author on the Optica paper and a scientist at Sandia National Laboratories in Albuquerque, New Mexico, USA who co-led a research team with fellow author and Sandia scientist Igal Brener.

These nanoscale cube-shaped resonators, based on the element tellurium, are each considerably smaller than the width of a human hair and even tinier than the wavelengths of infrared light, which is essential to achieve magnetic-mirror behavior at these incredibly short wavelengths.

"The size and shape of the resonators are critical," explained Sinclair "as are their magnetic and electrical properties, all of which allow them to interact uniquely with light, scattering it across a specific range of wavelengths to produce a magnetic mirror effect." 

Read More: http://www.osa.org/en-us/about_osa/newsroom/news_releases/2014/magnetic_mirrors_enable_new_technologies_by_reflec/


The magnetic molecule 'Gd7' used in the low-temperature experiment has the geometric structure of a snowflake. Photo: Nature Communications
An international team of scientists have become the first ever researchers to successfully reach temperatures below -272.15 C-only just above absolute zero-using magnetic molecules. The physicists and chemists are presenting their new investigation today (22 October 2014) in the scientific journal Nature Communications. It was developed by six scientists from Bielefeld University, the University of Manchester (Great Britain), and the Universidad de Zaragoza (Spain).

Scientists usually express temperatures on the Kelvin scale. Minus 272.15 C is precisely one Kelvin. This is why the researchers call their development 'sub-Kelvin cooling'. Cold temperatures are generally obtained by using an effect that anyone can observe with an aerosol can. If you press the button on the can for long enough, you will notice that whatever is being sprayed out gets colder. A normal refrigerator also uses this effect. In both cases, a gaseous refrigerant cools down as it expands due to the drop from high to low pressure.  

But how can we reach really low temperatures in the low Kelvin range? Nowadays, this is done by using helium as the refrigerant. However, helium is becoming increasingly scarce. "The very rare helium-3 isotope with which one can also get down to a few tenths of a Kelvin is now practically unaffordable," says Professor Dr. J�rgen Schnack, co-author of the study and physicist at Bielefeld University. Magnetic substances can also be used as refrigerants. These particularly include paramagnetic salts. Their cooling has nothing to do with pressure. They cool down when the external magnetic field generated by, for example, an electromagnet decreases. When the electric current is reduced in the coil, the magnetic field also decreases and the paramagnetic salts cool down.



Read more: http://www.rdmag.com/news/2014/10/cooling-near-absolute-zero-magnetic-molecules?et_cid=4225619&et_rid=614174443&type=headline


Schematic of the electrochemical cell-a silicon nitride (Si3N4) membrane separates the liquid from vacuum region of the x-ray source; a 20-nm thin-film gold electrode is deposited on liquid side of the membrane. Detection of x-ray absorption is via fluorescence emission on the vacuum side or electron emission at the gold electrode.
When a solid material is immersed in a liquid, the liquid immediately next to its surface differs from that of the bulk liquid at the molecular level. This interfacial layer is critical to our understanding of a diverse set of phenomena from biology to materials science. When the solid surface is charged, just like an electrode in a working battery, it can drive further changes in the interfacial liquid. However, elucidating the molecular structure at the solid-liquid interface under these conditions has proven difficult.

Now, for the first time, researchers at the U.S. Dept. of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have observed the molecular structure of liquid water at a gold surface under different charging conditions.

Miquel Salmeron, a senior scientist in Berkeley Lab's Materials Sciences Div. (MSD) and professor in UC Berkeley's Materials Science and Engineering Dept., explains this in the context of a battery. "At an electrode surface, the build-up of electrical charge, driven by a potential difference (or voltage), produces a strong electric field that drives molecular rearrangements in the electrolyte next to the electrode."


Read More: http://www.rdmag.com/news/2014/10/study-reveals-molecular-structure-water-gold-electrodes



Although fluorescence microscopy provides a crucial window into the physiology of living specimens, many biological processes are too fragile, are too small, or occur too rapidly to see clearly with existing tools. We crafted ultrathin light sheets from two-dimensional optical lattices that allowed us to image three-dimensional (3D) dynamics for hundreds of volumes, often at subsecond intervals, at the diffraction limit and beyond. We applied this to systems spanning four orders of magnitude in space and time, including the diffusion of single transcription factor molecules in stem cell spheroids, the dynamic instability of mitotic microtubules, the immunological synapse, neutrophil motility in a 3D matrix, and embryogenesis in Caenorhabditis elegans and Drosophila melanogaster. The results provide a visceral reminder of the beauty and the complexity of living systems.

Movie 5 High Resolution
Movie 5 High Resolution

Lattice light-sheet microscopy. An ultrathin structured light sheet (blue-green, center) excites fluorescence (orange) in successive planes as it sweeps through a specimen (gray) to generate a 3D image. The speed, noninvasiveness, and high spatial resolution of this approach make it a promising tool for in vivo 3D imaging of fast dynamic processes in cells and embryos, as shown here in five surrounding examples. Lattice light-sheet microscopy. An ultrathin structured light sheet (blue-green, center) excites fluorescence (orange) in successive planes as it sweeps through a specimen (gray) to generate a 3D image. The speed, noninvasiveness, and high spatial resolution of this approach make it a promising tool for in vivo 3D imaging of fast dynamic processes in cells and embryos, as shown here in five surrounding examples.


To address these limitations, we developed a new microscope using ultrathin light sheets derived from two-dimensional (2D) optical lattices. These are scanned plane-by-plane through the specimen to generate a 3D image. The thinness of the sheet leads to high axial resolution and negligible photobleaching and background outside of the focal plane, while its simultaneous illumination of the entire field of view permits imaging at hundreds of planes per second even at extremely low peak excitation intensities. By implementing either superresolution structured illumination or by dithering the lattice to create a uniform light sheet, we imaged cells and small embryos in three dimensions, often at subsecond intervals, for hundreds to thousands of time points at the diffraction limit and beyond.


Read More: http://www.sciencemag.org/content/346/6208/1257998
  Read more at: http://phys.org/news/2014-10-uv-irradiation-reversibly-graphene-hydrophobic.html


Atomic structures of a H2O or an O2 molecule adsorbed on graphene with different types of defects. Credit: Xu, Z. et al. Reversible Hydrophobic to Hydrophilic Transition in Graphene via Water Splitting Induced by UV Irradiation. Sci. Rep. 4, 6450.
(Phys.org) -Scientists have long observed that the wettability of graphene - an essentially two-dimensional crystalline allotrope of carbon that it interacts oddly with light and with other materials - can be reversed between hydrophobic and hydrophilic states by applying ultraviolet (UV) irradiation. However, an explanation for this behavior has remained elusive. Recently, researchers at The University of New South Wales and University of Technology, Sydney investigating this phenomenon both experimentally and by calculations using density functional theory (DFT) - a computational quantum mechanical modeling method - finding that UV irradiation enables this reversible and controllable transition in graphene films having induced defects by water splitting adsorption on the graphene surface of H2O molecules in air. (Water splitting is the chemically dissociative reaction in which water is separated into hydroxyl and hydrogen; hydroxyl is a chemical functional group containing an oxygen atom connected by a covalent bond to a hydrogen atom; and adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface.)

The scientists conclude that their discovery may provide new insights into the fundamental principles of water splitting with graphene-based materials, and could thereby lead to other applications - including electrocatalysis, nanomaterials; nanoelectromechanical systems, biomaterials, microfluidic devices, hybrid organic systems, and other advanced multifunctional systems.

Dr. Zhimin Ao discussed the paper that he, Doctoral Student Zhemi Xu and their co-authors published in Scientific Reports and the main challenges the researchers faced. "The main challenge - and the motivation for the conducting the study - was to reveal the real mechanism of the reversible wettability transition under UV irradiation and isolate it from various possible reasons, such as the contamination of chemicals on samples or induced by molecules in air," Ao tells Phys.org. "We also had to identify H2O rather than other possible molecules in air, which contributes the wettability transition under UV irradiation." After determining the contribution of H2O, he adds, another challenge was to understand the adsorption type of H2O for the wettability transition - that is, chemical or physical adsorption.




Read more at: http://phys.org/news/2014-10-uv-irradiation-reversibly-graphene-hydrophobic.html#jCp

Iron oxide nanoparticles on the surface of a cell. Image: EMPA

Empa toxicologist Harald Krug has lambasted his colleagues in the journal Angewandte Chemie. He evaluated several thousand studies on the risks associated with nanoparticles and discovered no end of shortcomings: poorly prepared experiments and results that don't carry any clout. Instead of merely leveling criticism, however, Empa is also developing new standards for such experiments within an international network.

Researching the safety of nanoparticles is all the rage. Thousands of scientists worldwide are conducting research on the topic, examining the question of whether titanium dioxide nanoparticles from sun creams can get through the skin and into the body, whether carbon nanotubes from electronic products are as hazardous for the lungs as asbestos used to be or whether nanoparticles in food can get into the blood via the intestinal flora, for instance. Public interest is great, research funds are flowing-and the number of scientific projects is skyrocketing: between 1980 and 2010, a total of 5,000 projects were published, followed by another 5,000 in just the last three years. However, the amount of new knowledge has only increased marginally. After all, according to Krug the majority of the projects are poorly executed and all but useless for risk assessments.



Read More at: http://www.rdmag.com/news/2014/10/nanoparticle-safety-quest-gold-standard?et_cid=4234593&et_rid=614174443&type=cta

Element Six polycrystalline CVD diamond optical window enabling higher-power carbon dioxide lasers. Images: Element Six
Diamonds aren't just a girl's best friend, they're also R&D's best friend-or at least a new acquaintance.

Many laboratories and companies are embracing synthetic diamond for its elevated super properties in applications ranging from analytical instruments and biomedical sensors to electronics and lasers to water purification.

A synthetic diamond's molecular structure makes it a versatile supermaterial. With greater hardness than other materials, its strength is ideal for cutters used in oil and gas drilling where it enables longer tool life by minimizing wear. In electroanalytical applications, synthetic diamond sensing materials provides stable electrochemical properties that enable high levels of sensitivity.

About 50% of electronic failures occur as a result of heat. And synthetic diamond's high thermal conductivity is four times higher than copper, and is the ideal material for thermal management. Synthetic diamond also has the widest spectral band of any material, extending from ultra violet to far infrared and the millimeter-wave microwave band, making it a suitable material for laser applications.

Lastly, synthetic diamond is chemically and biologically inert and can survive in severe physical, chemical and radioactive environments that destroy other materials.

There are two different forms of synthesis for synthetic diamond materials. One form is high-pressure, high-temperature (HPHT), a technique developed a few decades ago that emulates the environment when diamond is formed. The synthesis is conducted where a material scientist takes a number of precursors and form capsules and places these capsules under tremendous press under high temperatures. The other synthesis method is chemical vapor deposition (CVD), where diamond is grown layer by carbon layer.


Water beading on hydrophobic material

A pair of researchers from the UCLA Henry Samueli School of Engineering and Applied Science has created the first surface texture that can repel all liquids, no matter what material the surface is made of.

Because its design relies only on the physical attributes of the texture, the texture could have industrial or biomedical applications. For example, the surface could slow corrosion and extend the life of parts in chemical and power plants, solar cells or cookware.

Water will bead up on a nonstick cooking pan because it is coated with a hydrophobic material that repels water thanks to its chemical composition. If the hydrophobic material also is rough at the microscopic scale, it can trap air at its surface, causing the water to bead up and roll around effortlessly. Scientists have named such surfaces "superhydrophobic" to distinguish their unusual zeal to repel water. As an example in nature, water droplets will bead and roll down on some leaves.  


"At the microscopic scale, the leaves' surfaces are 'hairy' and points of contact with water are reduced," said Chang-Jin "CJ" Kim, a UCLA professor of mechanical and aerospace engineering, and the study's principal investigator. "This reduction in points of contact means the water is held up by its own surface tension. Manmade superhydrophobic surfaces have been designed to take advantage of this phenomenon by forming microscale roughness or patterns on a hydrophobic material."

While a nonstick cooking pan is hydrophobic, it is not "oleophobic," meaning that it does not repel oil-based liquids. Cooking oil spreads out rather than beading up because it has a lower surface tension than water, making it more difficult to repel. Since the material is not oleophobic, roughening it won't make its surface oleophobic, let alone "superoleophobic."

However, in recent years scientists have created certain microscopic textures capable of making surface hydrophobic materials' surfaces not only oleophobic but also superoleophobic.


Link to the journal article: http://www.sciencemag.org/content/346/6213/1096

By utilizing X-ray standing waves to excite photoelectrons, SWAPPS delivers vital information about all the chemical elements at the heterogeneous interfaces found in batteries, fuel cells and other devices.
Researchers working at the Advanced Light Source (ALS) of the U.S. Dept. of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have combined key features of two highly acclaimed x-ray spectroscopy techniques into a new technique that offers sub-nanometer resolution of every chemical element to be found at heterogeneous interfaces, such as those in batteries and fuel cells. This new technique is called SWAPPS for Standing Wave Ambient Pressure Photoelectron Spectroscopy, and it combines standing-wave photoelectron spectroscopy (SWPS) with high ambient pressure photoelectron spectroscopy (APPS).

"SWAPPS enables us to study a host of surface chemical processes under realistic pressure conditions and for systems related to energy production, such as electrochemical cells, batteries, fuel cells and photovoltaic cells, as well as in catalysis and environmental science," says Charles Fadley, a physicist who holds joint appointments with Berkeley Lab's Materials Sciences Div. and the Univ. of California Davis, where he is a Distinguished Professor of Physics. "SWAPPS provides all the advantages of the widely used technique of x-ray photoelectron spectroscopy, including element and chemical-state sensitivity, and quantitative analysis of relative concentrations of all species present. However with SWAPPS we don't require the usual ultrahigh vacuum, which means we can measure the interfaces between volatile liquids and solids."


 Link to the journal article: http://www.nature.com/ncomms/2014/141117/ncomms6441/abs/ncomms6441.html

Resistance and futility - How penicillin works
Penicillin, the wonder drug discovered in 1928, works in ways that are still mysterious almost a century later. One of the oldest and most widely used antibiotics, it attacks enzymes that build the bacterial cell wall, a mesh that surrounds the bacterial membrane and gives the cells their integrity and shape. Once that wall is breached, bacteria die, allowing us to recover from infection.
Bacteria in the plate on the left are susceptible to antibiotics but show resistance in the plate on the right. Image: James Gathany/CDC

That would be the end of the story, if resistance to penicillin and other antibiotics hadn't emerged over recent decades as a serious threat to human health. While scientists continue to search for new antibiotics, they still don't understand very much about how the old ones work.

Now Thomas Bernhardt, associate professor of microbiology and immunobiology at Harvard Medical School, and his colleagues have added another chapter to the story.

Their findings, published in Cell, reveal how penicillin deals bacteria a devastating blow, which may lead to new ways to thwart drug resistance.

Looking beyond penicillin's known targets in the cell wall, he and his team have shown that these drugs do more than simply block cell-wall assembly. Penicillin and its variants also set in motion a toxic malfunctioning of the cell's wall-building machinery, which dooms the cell to a futile cycle of building and then immediately destroying that wall. This downstream death spiral depletes cells of the resources they need to survive.



Journal article: http://www.sciencedirect.com/science/article/pii/S0092867414014482

New law for superconductors
Atoms of niobium and nitrogen in an ultrathin superconducting film that helped MIT researchers discover a universal law of superconductivity. Image: Yachin Ivry

Massachusetts Institute of Technology (MIT) researchers have discovered a new mathematical relationship-between material thickness, temperature and electrical resistance-that appears to hold in all superconductors. They describe their findings in Physical Review B.

The result could shed light on the nature of superconductivity and could also lead to better-engineered superconducting circuits for applications like quantum computing and ultra-low-power computing.

"We were able to use this knowledge to make larger-area devices, which were not really possible to do previously, and the yield of the devices increased significantly," says Yachin Ivry, a postdoctoral researcher in MIT's Research Laboratory of Electronics, and the first author on the paper.

Ivry works in the Quantum Nanostructures and Nanofabrication Group, which is led by Karl Berggren, a professor of electrical engineering and one of Ivry's co-authors on the paper. Among other things, the group studies thin films of superconductors.

Superconductors are materials that, at temperatures near absolute zero, exhibit no electrical resistance; this means that it takes very little energy to induce an electrical current in them. A single photon will do the trick, which is why they're useful as quantum photodetectors. And a computer chip built from superconducting circuits would, in principle, consume about one-hundredth as much energy as a conventional chip.

"Thin films are interesting scientifically because they allow you to get closer to what we call the superconducting-to-insulating transition," Ivry says. "Superconductivity is a phenomenon that relies on the collective behavior of the electrons. So if you go to smaller and smaller dimensions, you get to the onset of the collective behavior."

Vexing variation

Specifically, Ivry studied niobium nitride, a material favored by researchers because, in its bulk form, it has a relatively high "critical temperature"-the temperature at which it switches from an ordinary metal to a superconductor. But like most superconductors, it has a lower critical temperature when it's deposited in the thin films on which nanodevices rely.

Previous theoretical work had characterized niobium nitride's critical temperature as a function of either the thickness of the film or its measured resistivity at room temperature. But neither theory seemed to explain the results Ivry was getting. "We saw large scatter and no clear trend," he says. "It made no sense, because we grew them in the lab under the same conditions."

So the researchers conducted a series of experiments in which they held constant either thickness or "sheet resistance," the material's resistance per unit area, while varying the other parameter; they then measured the ensuing changes in critical temperature. A clear pattern emerged: Thickness times critical temperature equaled a constant-call it A-divided by sheet resistance raised to a particular power-call it B.



Journal article: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.214515

Freshman-level chemistry solves the solubility mystery of graphene oxide films
The image on the left shows the neat GO film, which disintegrated in water. The contaminated film on the right remains stable.

A Northwestern Univ.-led team recently found the answer to a mysterious question that has puzzled the materials science community for years-and it came in the form of some surprisingly basic chemistry.

Like many scientists, Jiaxing Huang did not understand why graphene oxide (GO) films were highly stable in water. When submerged, the individual GO sheets become negatively charged and repel each other, which should cause membrane to disintegrate. But earlier papers noted that instead of disintegrating, the films stabilized.

"It doesn't make any sense," said Huang, associate professor of materials science and engineering at the McCormick School of Engineering. "Many scientists have been very puzzled by this."

Graphene oxide, a product of graphite oxidation, is often used to make graphene, a single-atom-layer thick sheet of carbon that is remarkably strong, lightweight and has high potential in electronics and energy storage. Within the past three years, however, more scientists have become interested in GO itself, partially because of its potential for molecular separation applications.

After studying the material for many years, Huang realized that the secret of GO's mysterious insolubility was the unintentional introduction of a common contaminant. To make a GO film, many scientists pass the acidic dispersion of individual sheets through porous anodized aluminum oxide filter discs, which are popularly used for preparing membranes of many nanomaterials. Huang's team found that during filtration, the aluminum filter discs corrode in acidic water to release a significant number of aluminum ions, Al3+. The positively charged ion bonds with the negatively charged GO sheets to stabilize the resulting membranes.

"We have solved the puzzle using essentially freshman-level inorganic chemistry," Huang said. "Now we know that graphene oxide films are indeed soluble in water. It's just a matter of sample purity."





Journal article: http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2145.html

A calcium-silicate-hydrate (aka cement) tip hovers above a smooth tobermorite surface in a computer simulation by Rice Univ. scientists. The researchers studied how atomic-level forces in particulate systems interact when friction is applied. Their calculations show such materials can be improved for specific applications by controlling the materials' chemical binding properties. Image: Shahsavari Group 

Even when building big, every atom matters, according to new research on particle-based materials at Rice Univ.

Rice researchers Rouzbeh Shahsavari and Saroosh Jalilvand have published a study showing what happens at the nanoscale when "structurally complex" materials like concrete-a random jumble of elements rather than an ordered crystal-rub against each other. The scratches they leave behind can say a lot about their characteristics.

The researchers are the first to run sophisticated calculations that show how atomic-level forces affect the mechanical properties of a complex particle-based material. Their techniques suggest new ways to fine-tune the chemistry of such materials to make them less prone to cracking and more suitable for specific applications.

The research appears in Applied Materials and Interfaces.

The study used calcium-silicate-hydrate (C-S-H), aka cement, as a model particulate system. Shahsavari became quite familiar with C-S-H while participating in construction of the first atomic-scale models of the material.

C-S-H is the glue that binds the small rocks, gravel and sand in concrete. Though it looks like a paste before hardening, it consists of discrete nanoscale particles. The van der Waals and Coulombic forces that influence the interactions between the C-S-H and the larger particles are the key to the material's overall strength and fracture properties, said Shahsavari. He decided to take a close look at those and other nanoscale mechanisms.


Journal article: http://rouzbeh.rice.edu/uploadedFiles/Rouzbeh/Publications/2.pdf

Published on 01-07-2015 07:30 PM

At the heart of fabricating integrated circuits is the ability to selectively change the electrical properties of the semiconductor substrate. This key to fabrication is accomplished by doping - introducing atoms locally into the semiconductor substrate.

In the early days of the semiconductor industry doping was accomplished by creating a pattern on the surface of the semiconductor substrate typically in an oxide film and then depositing a doped glass over the surface. A subsequent heat treatment would then diffuse the dopants from the glass into the exposed semiconductor surface in some areas and the dopants would be blocked by the glass in other areas.

With the introduction of ion implantation for doping, solid source doping has largely disappeared (although Intel recently brought it back for one application in their 14nm process). Ion implantation utilizes a particle accelerator to inject dopants into the semiconductor material with high energies. Ion implant has several advantages over solid source doping, first and foremost is better control of the amount of dopant introduced. Ion implant can also better control the depth of the dopants and utilize photoresist as the mask for doping as opposed to requiring a film that can withstand high temperature; and Ion implantation can introduce nearly any atom of interest and does it at low temperature.



If you used any instruments in the Materials Science Center, Soft Materials Laboratory, or the Wisconsin Center for Applied Microelectronics, please remember to acknowledge MRSEC funded instruments and facilities in any publications (DMR-1121288). This will serve as a metric for how often MRSEC funded instruments are used and will help continue MRSEC support in future years. Thanks! If you have any questions, please contact Felix Lu.

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Hands-on laboratory experiences are not just for kids! Each month, a different activity encourages adult (18+) audiences to put on lab coats, goggles and gloves and get a firsthand sense of cutting-edge research.

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