Graphene in 2017: The Story So Far ~ An Update


Graphene 2017 ImageForArticle_4454(1)

In October 2004, University of Manchester’s Andre Geim, along with his colleague Kostya Novoselov, discovered published their discovery that when a block of graphite is broken down to just 10 or 100 layers thick, a material known as graphene emerges1.

With substantial material properties involving its superior strength as well as both heat and electricity conductibility, while remaining such a thin material, graphene has become one of the most studied materials to date.

While graphene is most often employed in disciplines such as bioengineering, composite materials, energy technology and nanotechnology, its ability to be interjected with other elements allows for its applications to be limitless.directa-plus-colmar-graphene-ski-jacket

One of the most pressing challenges that the graphene industry faces is a lack of pure production of the material. A recent research report conducted by the Centre for Advanced 2 D Materials (CA2DM) at the National University of Singapore has found that most graphene production companies generate a material that is comprised of a graphene content of only 2-10%2.

Canadian based company Elcora Advanced Materials Corporation has become one of the leading graphene producers in the world, while also maintaining products comprised of 55% graphene content. As its unique designed processing technology not only works towards achieving the purest form of graphene possible, Elcora ensures the cost effective production of graphene from natural graphite in a green and efficient manner.

Learn more about Elcora Advanced Materials

By minimizing the need for using harsh chemicals, while also eliminating the environmentally damaging byproducts or waste that often follow graphene production, Elcora is one of the most environmentally safe graphene plants available today3.

After acquiring control of the Ragedera graphite mine located in Colombo, Sri Lanka, Elcora Advanced Material has been able to successfully produce an estimated 18,000 tonnes of high quality graphite per year.

 

With production bases located in both South Wales and Seoul, Korea, Haydale Graphene Industries is one of the numerous companies working towards enhancing the carbon fiber composites for specific aerospace and automotive needs. In doing so, research conducted by both Haydale and scientists from the School of Engineering at Cardiff University have investigated how the addition of graphene nanoplaatelets (GP) and carbon nanotubes (CNT) into the composites can allow for reinforcing benefits of the technology.

These benefits include an increased resistance and tolerance to damage of the vehicle, while also showing a 13% increase in the compression strength following impact performance studies. By positively influencing composites such as aircraft wings and automobile parts, Haydale has improved these important properties that are required for maintaining such high performance structures4.

Learn more about Haydale

In addition to achieving such impressive material improvements, the techniques employed during this process were performed in a much more cost effective, green and efficient manner. The process employed in the development of this composite involved treating the surface of the nanomaterials with Haydale’s low temperature and low energy HDPlas ® plasma process4.

This plasma functionalization process not only produces high integrity materials, but also avoids the typical waste production associated with functionalization processes while simultaneously promoting homogenous dispersion and chemical bonding. Haydale researchers are hopeful that this newly developed material can allow for lighter and stronger wings to be implemented into aircraft deisgns that can simultaneously reduce the amount of carbon dioxide emissions released by these aircrafts.

Rahul Nair from the University of Manchester in the United Kingdom has recently developed a method involving the use of graphene oxide in order to effectively desalinate water. Considered to be the oxidized form of graphene, graphene oxide membranes have recently emerged as an excellent membrane material that is capable of separating multiple different types of molecules and ions present in an aqueous solution5.

The sieving potential of graphene oxide membranes has been successful in removing small nanoparticles, organic molecules and large salts from solution; however, their ability to filter out common salts has not been documented until now. Previous attempts at employing graphene oxide membranes in the filtration of smaller salts in water have caused the membranes to expand and prevent the flow of water from entering the pores of the membrane.Graphene Mem 050815 3-anewapproach

By placing walls composed of a substance known as epoxy resin that is typically used in glues and coatings on either side of the graphene oxide membrane, the team of researchers led by Dr. Nair was able to successfully prevent the swelling of the membranes upon its immersion in water6.

With a uniform pore size within the membrane of only 0.9 nm in width, this highly selective graphene oxide membrane has several advantages as compared to its bulk counterpart, graphene7. As a much more inexpensive option coupled with a long operational lifetime, graphene oxide membranes have a spectacular separation potential that could have a significant impact in a wide variety of energy reduction and environmental conservation industries around the world.

Outside of its potential for water purification purposes, researchers believe that this technology could also provide a useful addition in the dehydration and purification of biofuels. In most biofuel processes, water is formed as a byproduct, and its presence in the biofuel can affect the final product in a detrimental way. Therefore, the hope is that the application of graphene oxide membranes in this industrial process could have an advantageous use.

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Similarly, graphene oxide membranes have a well-documented gas separation ability that prevents any vapor molecules from passing through the membrane. In one of the first studies illustrating this property, researchers measured the loss of weight within a containing initially filled with alcohol before and after it was sealed with a graphene oxide membrane8.

Following the membrane sealing, researchers found that no noticeable variation in the weight of or the pressure within the container was detected. As a result of this remarkable gas separation property, researchers are hopeful the use of graphene oxide membranes can be applied to the controlling of greenhouse gas emissions, as well as the purification of hydrogen-related clean energy gases, in future real world applications.

The University of Cambridge has recently developed a highly conductive ink known as ‘Graphene – IPA Ink.” Composed of powdered graphite dissolved in alcohol, this ink has the potential to be used in inkjet printers that print electrical circuits onto paper.

By forcing the ink through a micrometer-scale capillary at an extremely high pressure, the resulting product is a smooth and conductive material9. Researchers are hopeful that devices such as Radio Frequency Identification (RFID) antennas, passports, electronic tags, and similar everyday items can be printed at a much cheaper rate with the application of electronic circuits printed using this graphene ink.Graphene defectsarepe

While graphene may appear to be a single product, it has developed into several different types of applications in its short 13-year live span since its first entrance into the scientific world. Its wide range of uses allow for this material to have a promising future, in which its varying and impressive properties of transparency, strength and conductivity can improve almost every industry of the world.

The world of two-dimensional materials, like graphene, have allowed for researchers to manipulate different geometries and combinations of these compounds to create wonderful new products of the future. As research and development projects continue to work on graphene and its numerous applied products, new two-dimensional materials continue to be discovered each day in continuance of this revolutionary pathway that has set by graphene.

References

  1. “This Month in Physics History.” American Physical Society. 22 Oct. 2014. Web. https://www.aps.org/publications/apsnews/200910/physicshistory.cfm.
  2. “Graphene R&D.” Elcora Advanced Materials. Web. https://www.elcoracorp.com/graphene-rd/.
  3. Ecclestone, Christopher. “Analyst on How Elcora Has Positioned Themselves as a Leader in the Graphite Space.” InvestorIntel. 06 Apr. 2017. Web. https://investorintel.com/sectors/technology-metals/technology-metals-intel/elcora-pulling-ahead-leadership-graphite-space/.
  4. “Carbon Fibre Composites.” Haydale. 11 Nov. 2014. Web. http://www.haydale.com/news/graphene-toughened-composites-a-milestone-for-next-generation-aerospace-structures/.
  5. An, Di, Ling Yang, Ting-Jie Wang, and Boyang Liu. “Separation Performance of Graphene Oxide Membrane in Aqueous Solution.” Industrial & Engineering Chemistry Research 55.17 (2016): 4803-810. Web.
  6. Rincon, Paul. “Graphene-based Sieve Turns Seawater into Drinking Water.” BBC News. BBC, 03 Apr. 2017. Web. http://www.bbc.com/news/science-environment-39482342.
  7. Wilkinson, Jake. “Developing Graphene Oxide Membranes for the Purification of Water and Green Fuels.” AZoNano.com. 22 Sept. 2016. Web. http://www.azonano.com/article.aspx?ArticleID=4275.
  8. Joshi, R.k., S. Alwarappan, M. Yoshimura, V. Sahajwalla, and Y. Nishina. “Graphene Oxide: The New Membrane Material.” Applied Materials Today 1.1 (2015): 1-12. Web.
  9. “Conductive Graphene Ink Wins Science Photography Competition’s Top Prize.” Phys.org. Web. https://phys.org/news/2017-04-graphene-ink-science-photography-competition.html.
  10. Image Credit: Shutterstock.com/OliveTree

 

Link to Original Article from AzNano

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Researchers Create Unique Hybrid Nanomaterials to Transform Dirty Water into Drinkable Water


Graphene Hybrid Water072916 NewsImage_34896An artist’s rendering of nanoparticle biofoam developed by engineers at Washington University in St. Louis. The biofoam makes it possible to clean water quickly and efficiently using nanocellulose and graphene oxide. (Photo credit: Washington University in St. Louis)

Recently, a team of researchers from Washington University in St. Louis have discovered a method to use graphene oxide sheets to convert dirty water into drinking water. This could easily become a worldwide game-changer.

“We hope that for countries where there is ample sunlight, such as India, you’ll be able to take some dirty water, evaporate it using our material, and collect fresh water,” said Srikanth Singamaneni, associate professor of mechanical engineering and materials science at the School of Engineering & Applied Science.

The new method integrates graphene oxide and bacteria-produced cellulose to create a bi-layered biofoam. A paper explaining the research can be found online in Advanced Materials.

The process is extremely simple. The beauty is that the nanoscale cellulose fiber network produced by bacteria has excellent ability move the water from the bulk to the evaporative surface while minimizing the heat coming down, and the entire thing is produced in one shot. The design of the material is novel here. You have a bi-layered structure with light-absorbing graphene oxide filled nanocellulose at the top and pristine nanocellulose at the bottom.

When you suspend this entire thing on water, the water is actually able to reach the top surface where evaporation happens. Light radiates on top of it, and it converts into heat because of the graphene oxide — but the heat dissipation to the bulk water underneath is minimized by the pristine nanocellulose layer. You don’t want to waste the heat; you want to confine the heat to the top layer where the evaporation is actually happening.

Srikanth Singamaneni, Associate Professor, Washington University

The bottom of the bi-layered biofoam has the cellulose, which acts as a sponge, sucking water up to the graphene oxide where fast evaporation occurs. The resulting fresh water found at the top of the sheet can be effortlessly collected.

The method used to form the bi-layered biofoam is also new.

The graphene oxide flakes are embedded into the layers of nanocellulose fibers, which are formed by the bacteria. Using the same method used by an oyster to make a pearl, the bacteria create these layers.

While we are culturing the bacteria for the cellulose, we added the graphene oxide flakes into the medium itself. The graphene oxide becomes embedded as the bacteria produce the cellulose. At a certain point along the process, we stop, remove the medium with the graphene oxide and reintroduce fresh medium. That produces the next layer of our foam. The interface is very strong; mechanically, it is quite robust.

Qisheng Jiang, Graduate Student, Washington University

The new biofoam is also very light and cost-efficient to make, thus making it a feasible tool for desalination and water purification.

“Cellulose can be produced on a massive scale,” Singamaneni said, “and graphene oxide is extremely cheap — people can produce tons, truly tons, of it. Both materials going into this are highly scalable. So one can imagine making huge sheets of the biofoam.”

“The properties of this foam material that we synthesized has characteristics that enhances solar energy harvesting. Thus, it is more effective in cleaning up water,” said Pratim Biswas, the Lucy and Stanley Lopata Professor and chair of the Department of Energy, Environmental and Chemical Engineering.

“The synthesis process also allows addition of other nanostructured materials to the foam that will increase the rate of destruction of the bacteria and other contaminants, and make it safe to drink. We will also explore other applications for these novel structures.”

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MIT: Researchers Create Potential “Nano-Water Filters” : Video


MIT-Nanoscrolls-1_0Researchers create perfect nanoscrolls from graphene’s imperfect form.

Water filters of the future may be made from billions of tiny, graphene-based nanoscrolls. Each scroll, made by rolling up a single, atom-thick layer of graphene, could be tailored to trap specific molecules and pollutants in its tightly wound folds. Billions of these scrolls, stacked layer by layer, may produce a lightweight, durable, and highly selective water purification membrane.

But there’s a catch: Graphene does not come cheap. The material’s exceptional mechanical and chemical properties are due to its very regular, hexagonal structure, which resembles microscopic chicken wire. Scientists take great pains in keeping graphene in its pure, unblemished form, using processes that are expensive and time-consuming, and that severely limit graphene’s practical uses.

Seeking an alternative, a team from MIT and Harvard University is looking to graphene oxide — graphene’s much cheaper, imperfect form. Graphene oxide is graphene that is also covered with oxygen and hydrogen groups. The material is essentially what graphene becomes if it’s left to sit out in open air. The team fabricated nanoscrolls made from graphene oxide flakes and was able to control the dimensions of each nanoscroll, using both low- and high-frequency ultrasonic techniques. The scrolls have mechanical properties that are similar to graphene, and they can be made at a fraction of the cost, the researchers say.

“If you really want to make an engineering structure, at this point it’s not practical to use graphene,” says Itai Stein, a graduate student in MIT’s Department of Mechanical Engineering. “Graphene oxide is two to four orders of magnitude cheaper, and with our technique, we can tune the dimensions of these architectures and open a window to industry.”

Stein says graphene oxide nanoscrolls could also be used as ultralight chemical sensors, drug delivery vehicles, and hydrogen storage platforms, in addition to water filters. Stein and Carlo Amadei, a graduate student at Harvard University, have published their results in the journalNanoscale.

Getting away from crumpled graphene

The team’s paper originally grew out of an MIT class, 2.675 (Micro/Nano Engineering), taught by Rohit Karnik, associate professor of mechanical engineering. As part of their final project, Stein and Amadei teamed up to design nanoscrolls from graphene oxide. Amadei, as a member of Professor Chad Vecitis’ lab at Harvard University, had been working with graphene oxide for water purification applications, while Stein was experimenting with carbon nanotubes and other nanoscale architectures, as part of a group led by Brian Wardle, professor of aeronautics and astronautics at MIT.

The researchers’ graphene nano scroll research originated in this MIT classes 2.674 and 2.675 (Micro/Nano Engineering Laboratory).

Video: Department of Mechanical Engineering

“Our initial idea was to make nanoscrolls for molecular adsorption,” Amadei says. “Compared to carbon nanotubes, which are closed structures, nanoscrolls are open spirals, so you have all this surface area available to manipulate.”

“And you can tune the separation of a nanoscroll’s layers, and do all sorts of neat things with graphene oxide that you can’t really do with nanotubes and graphene itself,” Stein adds.

When they looked at what had been done previously in this field, the students found that scientists had successfully produced nanoscrolls from graphene, though with very complicated processes to keep the material pure. A few groups had tried doing the same with graphene oxide, but their attempts were literally deflated.

“What was out there in the literature was more like crumpled graphene,” Stein says. “You can’t really see the conical nature. It’s not really clear what was made.”

Collapsing bubbles

Stein and Amadei first used a common technique called the Hummers’ method to separate graphite flakes into individual layers of graphene oxide. They then placed the graphene oxide flakes in solution and stimulated the flakes to curl into scrolls, using two similar approaches: a low-frequency tip-sonicator, and a high-frequency custom reactor.

The tip-sonicator is a probe made of piezoelectric material that shakes at a low, 20Hz frequency when voltage is applied. When placed in a solution, the tip-sonicator produces sound waves that stir up the surroundings, creating bubbles in the solution.

Similarly, the group’s reactor contains a piezoelectric component that is connected to a circuit. As voltage is applied, the reactor shakes — at a higher, 390 Hz frequency compared with the tip-sonicator — creating bubbles in the solution within the reactor.

Stein and Amadei applied both techniques to solutions of graphene oxide flakes and observed similar effects: The bubbles that were created in solution eventually collapsed, releasing energy that caused the flakes to spontaneously curl into scrolls. The researchers found they could tune the dimensions of the scrolls by varying the treatment duration and the frequency of the ultrasonic waves. Higher frequencies and shorter treatments did not lead to significant damage of the graphene oxide flakes and produced larger scrolls, while low frequencies and longer treatment times tended to cleave flakes apart and create smaller scrolls.

While the group’s initial experiments turned a relatively low number of flakes — about 10 percent — into scrolls, Stein says both techniques may be optimized to produce higher yields. If they can be scaled up, he says the techniques can be compatible with existing industrial processes, particularly for water purification.

“If you can make this in large scales and it’s cheap, you could make huge bulk samples of filters and throw them out in the water to remove all sorts of contaminants,” Stein says.

This work was supported, in part, by the Department of Defense through the National Defense Science and Engineering Graduate (NDSEG) fellowship program.

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Graphene Improves Oil Exploration


carbon-nanotube(Nanowerk News) Graphene holds potential for diverse applications, including battery materials, electrodes, high-speed electronics, water filtration, and solar energy harvesting. We’ve discussed most of those applications in earlier blog posts, and not a day passes without some progress in one of those directions hitting the world headlines. Little media attention, however, has been paid to a young and exciting application of graphene – oil exploration.
Most of the world’s growing energy demand is fulfilled from some form of fossil fuel, like coal and oil. It is well known that oil exploration and the energy sector are big business, but also potentially damaging to the environment. Oil spills and uncontrolled oil well explosions form just a part of the risk involved in oil exploration. Another cause for concern is the efficiency of extraction, and potential losses, or leaks of oil into the environment. Graphene is being explored for its use in various stages of the exploration and extraction process.
Much of the research on graphene for oil has come out of the lab of Prof. James Tour at Rice University. In their early work (published in 2012: “Graphene Oxide as a High-Performance Fluid-Loss-Control Additive in Water-Based Drilling Fluids”), the group first showed that adding platelets of graphene oxide to a common water-based drilling fluid decreased the losses of the fluid to the surrounding rock, as compared to a standard mixture of clays and polymers used in the drilling industry today.
Graphene platelet plugging a nanopore
Graphene platelet plugging a nanopore (from ACS Applied Materials and Interfaces 4, 222 (2012))
These fluids are pumped downhole as part of the process to keep drill bits clean and remove cuttings. With traditional clay-enhanced fluids, differential pressure forms a layer on the wellbore called a filter cake, which both keeps the oil from flowing out and drilling fluids from invading the tiny, oil-producing pores.
When the drill bit is removed and drilling fluid displaced, the formation oil forces remnants of the filter cake out of the pores as the well begins to produce. But sometimes the clay won’t budge, and the well’s productivity is reduced.
The Tour Group discovered that microscopic, pliable flakes of graphene can form a thinner, lighter filter cake (“Functionalized graphene oxide plays part in next-generation oil-well drilling fluids”). When they encounter a pore, the flakes fold in upon themselves and look something like starfish sucked into a hole. But when well pressure is relieved, the flakes are pushed back out by the oil. The thinner graphene layer budged much more easily than the the layer which would remain after a traditional clay-enhanced liquid was used. A drilling fluid with 2 percent functionalized graphene oxide formed a filter cake an average of 22 micrometers wide — substantially smaller than the 278-micrometer cake formed by traditional drilling fluids. GO blocked pores many times smaller than the flakes’ original diameter by folding.
Graphene can also be put to use for well logging. Well logging techniques provide data on the geological properties of reservoirs of interest to the oil and gas exploration industry. A commonly used logging technique uses wirelines to provide information about an oil or gas well. Wirelines are long wires with sensors attached to them, which are lowered into an exploration hole to provide information about the hole and its contents. An extension of wireline logging is logging-while-drilling, which relies on sensors at the end of the drill itself. Both methods utilize oil-based fluids for drilling and lubrication. Oil-based fluids, however, are not very good conductors of electricity, which is where graphene enters the scene. The group of Tour developed a solution that contains magnetic graphene nanoribbons (MGNRs). The MGNRs form part of a conductive coating in oil-based drilling fluids, improving the reliability of the information that is sent back up the hole by the sensors. Furthermore, the magnetic properties of the ribbons could also be exploited for using the ribbons themselves as advanced sensors. The Tour group filed a patent for this application.
Finally, since graphene nanoribbons can be made small enough to pass into tiny crevices of the rock which holds precious oil, some envision little graphene-based robots creeping through rocks, sending wireless data which contains information on oil location and concentration.
Source: By  Marko Spasenovic, Graphenea

Read more: http://www.nanowerk.com/nanotechnology_news/newsid=33733.php#ixzz2nlSIv0fw

Graphene-based discs ensure safe storage


Graphene-based discs ensure safe storage

(Phys.org) —Swinburne University of Technology researchers have shown the potential of a new material for transforming secure optical information storage.

In their latest research paper published in Scientific Reports, researchers Xiangping Li, Qiming Zhang, Xi Chen and Professor Min Gu demonstrated the potential to record holographic coding in a polymer composite.

“Conventionally, information is recorded as binary data in a disc. If the disc is broken, the information cannot be retrieved,” Director of the Centre for Micro-Photonics at Swinburne, Professor Min Gu, said.

“This is a major operation cost in big data centres, which consist of thousands of disc arrays with multiple physical duplicates of data. The new material allows the development of super-discs, which will enable information to be retrieved – even from broken pieces.”

Graphene oxide is similar to graphene, discovered by Andre Geim and Konstantin Novoselov, who received the 2010 Nobel Prize in Physics for this groundbreaking discovery. Graphene is very strong, light, flexible, nearly transparent, and is an excellent conductor of heat and electricity.

Graphene oxide has similar properties, but also has a fundamental fluorescent property that can be used in bioimaging and for multimode optical recording.

By focusing an ultrashort laser beam onto the graphene oxide polymer, the researchers created a 10-100 times increase in the of the graphene oxide along with a decrease in its fluorescence. (The refractive index is the measure of the bending of light as it passes through a medium.)

“The unique feature of the giant refractive-index modulation together with the fluorescent property of the graphene oxide polymer offers a new mechanism for multimode optical recording,” Professor Gu said.

To demonstrate the feasibility of the mechanism, the researchers encoded the image of a kangaroo in a computer generated hologram. The hologram was then rendered as a three-dimensional recording to the graphene oxide polymer. The encrypted patterns in the hologram could not be seen as a normal microscope image, but could be retrieved in the diffracted mode.

“The giant refractive index of this material shows promise for merging data storage with holography for security coding,” Professor Gu said.

“This exciting feature not only boosts the level of storage security, but also helps to reduce the operation costs of big data centres that rely on multiple physical duplicates to avoid data loss.”

The researchers say it could also revolutionise flat screen TV and solar cell technology.

“More importantly, graphene has been deemed as a revolutionary replacement for silicon, which is the platform for current information technologies based on electronics,” Dr Xiangping Li said.

“The giant refractive index we discovered shows the promise of to merge electronics and photonics for the platform of the next generation information technologies.”

Read more at: http://phys.org/news/2013-10-graphene-based-discs-safe-storage.html#jCp

Read more at: http://phys.org/news/2013-10-graphene-based-discs-safe-storage.html#jCp

Bursting through the Silicon Barrier: Developing Carbon-based Nanoelectronics with Graphene


On the road towards creating smaller and smaller electronic  devices, silicon blocks the way by limiting the smallness of the electronic  components that can be constructed with it.   A promising way forward has been found by using carbon instead and its study  has resulted in a rapidly growing field.   In a work published in ACS Nano, using tools including those found at  the Synchrotron Radiation Center, scientists have developed a process for making  a never-before-seen, atomically thin, composite material containing ordered  layers of graphene and nanocrystals of graphene monoxide.

Graphene, composed of an atomically thin layer of carbon, does not  by itself have the necessary properties that lend itself for use in modern  nanoelectronics.  To achieve this, other  elements need to be added to the mix.  When  oxygen is added chemically to graphene, for example, a property called the band-gap  is created.  The band-gap determines the  electrical conductivity of a material, an important factor in creating useful  electronic devices.  However, at this  stage, the mix is a disorganized arrangement of atoms, and results in poor  electronic properties, including the band-gap. Because of this it can only be  used in basic electronic devices such as supercapacitors, sensors, and flexible  transparent conductive electrodes.

In this publication researchers describe a method for annealing  (heating) the graphene and oxygen mix resulting in a previously unobserved  atomic structure.  It is comprised of  layers of oxygen poor graphene sandwiched between layers of oxygen rich graphene  (graphene oxide).

In the image, the number of rings  corresponds to the complexity of the different structures in the Graphene-Oxide  (G-O) compound.  The left side of the  image corresponds to the G-O compound before annealing (heating).  The right side of the image, corresponding to  the compound after annealing, shows additional rings indicating a more complex  and ordered structure.

Scientists determined that the new carbon based structure shows  promise allowing them to tailor it creating, for example, ideal “band gaps” for  use in nanoelectronic devices such as sensors, transistors, and optoelectronic  devices.

This work was published in the journal ACS Nano by SRC Users Eric Mattson (lead author), Michael Nasse, and Carol Hirschmugl.  Additional members of the scientific team  included faculty and students from the University of Wisconsin-Milwaukee and  the University of Texas at Austin.  This  paper can be found online at: http://pubs.acs.org/doi/abs/10.1021/nn203160n