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MIT's Michael Strano turns plants into chemical detectors

Posted By Terrance Barkan, Monday, October 31, 2016

Scientists have transformed the humble spinach plant into a bomb detector.

Source: MIT

By embedding tiny tubes in the plants' leaves, they can be made to pick up chemicals called nitro-aromatics, which are found in landmines and buried munitions. Real-time information can then be wirelessly relayed to a handheld device.

The MIT (Massachusetts Institute of Technology) work is published in the journal Nature Materials. The scientists implanted nanoparticles and carbon nanotubes (tiny cylinders of carbon) into the leaves of the spinach plant. It takes about 10 minutes for the spinach to take up the water into the leaves.

To read the signal, the researchers shine a laser onto the leaf, prompting the embedded nanotubes to emit near-infrared fluorescent light. This can be detected with a small infrared camera connected to a small, cheap Raspberry Pi computer. The signal can also be detected with a smartphone by removing the infrared filter most have.

Co-author Prof Michael Strano, from MIT in Cambridge, US, said the work was an important proof of principle. "Our paper outlines how one could engineer plants like this to detect virtually anything," he told the BBC News website.

Prof Strano's lab has previously developed carbon nanotubes that can be used as sensors to detect hydrogen peroxide, TNT, and the nerve gas sarin. When the target molecule binds to a polymer material wrapped around the nanotube, it changes the way it glows. "The plants could be use for defence applications, but also to monitor public spaces for terrorism related activities, since we show both water and airborne detection," said Prof Strano.

"Such plants could be used to monitor groundwater seepage from buried munitions or waste that contains nitro-aromatics." Using the set-up described in the paper, the researchers can pick up a signal from about 1m away from the plant, and they are now working on increasing that distance.

Source: BBC News

Tags:  Carbon Nanotubes  Michael Strano  MIT  Sensors 

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Electronics Applications for Graphene Hold Great Promise

Posted By Terrance Barkan, Monday, October 31, 2016

Applications that have really spurred a huge amount of graphene and other two-dimensional (2D) material research over the years have come from the field of electronics. The fear that complementary metal–oxide–semiconductor (CMOS) technology is quickly nearing the end of its ability to ward off Moore’s Law, in which the number of transistors in a dense integrated circuit doubles approximately every two years, has been the spur for much graphene research.

However, there has always been the big problem for graphene that it does not have an intrinsic band gap. It’s a pure conductor and not a semiconductor, like silicon, capable turning on and off the flow of electrons through it. While graphene can be functionalized in a way that it does have a band gap, research for it in the field of electronics have looked outside of digital logic where an intrinsic band gap is such an advantage. 

In the stories below, we see how graphene’s unrivaled conductivity is being exploited to take advantage of its strengths rather than trying to cover up for its weaknesses.

Graphene Comes to the Rescue of Li-ion Batteries

The role of graphene in increasing the charge capacity of the electrodes in lithium-ion (Li-ion) batteries has varied. There’s been “decorated graphene” in which nanoparticles are scattered across the surface of the graphene, and graphene nanoribbons, just to name a few of the avenues that have been pursued.

Another way in which graphene has been looked at is to better enable silicon to serve as the electrode material for Li-ion batteries. Silicon is a great material for increasing the storage capacity of electrodes in Li-ion batteries, but there’s one big problem: it cracks after just few charge/discharge cycles. The aim has been to find a way to make silicon so that it’s not so brittle and can withstand the swelling and shrinking during the charge charging and discharing of lithium atoms into the electrode material In these efforts, like those out Northwestern University, the role of graphene has been to sandwich silicon between layers graphene sheets in the anode of the battery.

Now, Yi Cui from both Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory, who has been at the forefront of research to get silicon to be more flexible and durable for Li-ion batteries, has turned to graphene to solve the issue

Cui and his colleagues were able to demonstrate in research described in the journal Nature Energy, a method for to encasing each particle of silicon in a cage of graphene that enables the silicon to expand and contract without cracking. In a full-cell electrochemical test, the graphene-infused silicon anodes retained 90 percent of their charge capacity after 100 charge-discharge cycles. 

Previous attempts by Cui and many others to create nanostructured silicon has been very difficult, making mass production fairly impractical. However, based on these latest results, Cui believes that this approach is not only technologically possible, but may in fact be commercially viable.

The process involves coating the silicon particles with a layer of nickel. The nickel coating is used as the surface and the catalyst for the second step: growing the graphene. The final step of the process involves using an acid on the graphene-coated silicon particles so that the nickel is etched away.

“This new method allows us to use much larger silicon particles that are one to three microns, or millionths of a meter, in diameter, which are cheap and widely available,” Cui said in a press release. “Particles this big have never performed well in battery anodes before, so this is a very exciting new achievement, and we think it offers a practical solution.”

While a practical manufacturing approach was much needed, the technique also leads to an electrode material with very high charge capacity.

“Researchers have tried a number of other coatings for silicon anodes, but they all reduced the anode’s efficiency,” said Stanford postdoctoral researcher Kai Yan, in a press release. “The form-fitting graphene cages are the first coating that maintains high efficiency, and the reactions can be carried out at relatively low temperatures.”

Graphene Provides the Perfect Touch to Flexible Sensors

 

Photo: Someya Laboratory

Flexible sensors are the technological backbone of artificial skin technologies. The idea is that you can impart the sense of touch to a flexible sensor, making it possible to cover a prosthetic device for either a robot or replacement limb so it can feel. Creating materials that tick the boxes of flexibility, durability and sensitivity has been a challenge. Over the years, researchers have increasingly turned to nanomaterials, and graphene in particular, as a possible solution. 

Researchers at the University of Tokyo have found that nanofibers produced from a combination of carbon nanotubes and graphene overcomes some of the big problems facing flexible pressure sensors: they’re not that accurate after being bent or deformed. The researchers have suggested that the flexible sensor they have developed could provide a more accurate detection breast cancer.

In research described in the journal Nature Nanotechnology, the scientists produced their flexible sensor by employing organic transistors and a pressure sensitive nanofiber structure.

The researchers constructed the nanofiber structure using nanofibers with diameters ranging between 300 to 700 nanometers. The researchers produced the nanofibers by combining carbon nanotubes and graphene and mixing that into a flexible polymer. The nanofibers entangled with each other to form a thin, transparent structure.

In contrast to other flexible sensors in which the striving for accuracy makes the sensors too sensitive to being deformed in any way, the fibers in this new flexible sensor does not lose their accuracy in measuring pressures. These fibers achieve this because of their ability to change their relative alignment to accommodate the bending. This allows them to continue measuring pressure because it reduces the strain in individual fibers.

Tunable Graphene Plasmons Lead to Tunable Lasers

Illustration: University of Manchester

A few years ago, researchers found that the phenomenon that occurs when photons strike a metallic surface and stir up the movement of electrons on the surface to the point where the electrons form into waves—known as surface plasmons—also occurs in graphene. 

This discovery along with the ability to tune the graphene plasmons has been a big boon for the use of graphene in optoelectronic applications.  Now research out of the University of Manchester, led by Konstantin Novoselov, who along with Andre Geim were the two University of Manchester scientists who won the Nobel Prize for discovering graphene, has leveraged the ability of tuning graphene plasmons and combined it with terahertz quantum cascade lasers, making it possible to reversibly alter their emission. 

This ability to reversibly the alter the emission of quantum cascade lasers is a big deal in optoelectronic applicatiopns, such as fiber optics telecommunication technologies by offering potentially higher bandwidth capabilities.

“Current terahertz devices do not allow for tunable properties, a new device would have to be made each time requirements changed, making them unattractive on an industrial scale,” said Novoselov in a press release. “Graphene however, can allow for terahertz devices to be switched on and off, as well as altering their state.”

In research described in the journal Science, were able to manipulate the doping levels of a graphene sheet so that it generated plasmons on its surface. When this doped graphene sheet was combined with a terahertz quantum cascade laser, it became possible to tune the transmission of the laser by tuning the graphene plasmons, essentially changing the concentration of charge carriers.

Graphene Flakes Speed Up Artificial Brains

Illustration: Alexey Kotelnikov/Alamy


Researchers out of Princeton University have found that graphene flakes could be a key feature in computer chips that aim at mimicking the function of the human brain. 


In the human brain, neurons are used to transmit information by passing electrical charges through them. In artificial brains, transistors would take the place of neurons. One approach has been to construct the transistors out of lasers that would turn and off and the time intervals between the on and off states of the lasers would represent the 1s and 0s of digital logic.

One of the challenges that researchers have faced in this design is getting the time intervals between the laser pulses down to picosecond time scales, one trillionth of a second.

In research described in the journal Nature Scientific Reports, the Princeton researchers placed graphene flakes inside a semiconductor laser to act as a kind of “saturable absorber,” that absorbed photons and then was able to emit them in a quick burst. 

It turns out graphene possesses a number of properties that makes it attractive for this application. Not only can it absorb and release photons extremely quickly, but it can also work at any wavelength. What this means is that even if semiconductor lasers are emitting different colors, the graphene makes it possible for them to work together simultaneously without interfering with each other, leading to higher processing speeds.

 

 

 

 

 

Tags:  Batteries  Decorated Graphene  Electronics  Flexible Sensors  Graphene  Graphene Nanoribbons  Lasers  Li-ion  optoelectronics  Semiconductor 

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Graphene "Sandwich" Supercapcitor

Posted By Terrance Barkan, Wednesday, October 26, 2016

Ramakrishna Podila and Apparao Rao at the Clemson Nanomaterials Center, along with graduate students Jingyi Zhu and Anthony Childress, have discovered how to increase by five-fold the energy capacity of supercapacitors without sacrificing strength or durability using specially designed layers of atom-thick carbon sheets called graphene.

For the average person who may use but never see a supercapacitor, Clemson’s work means faster charging times, longer lives, a lighter power source than batteries, reduced dependency on fossil fuels, tons less air pollution and possibly lower energy prices.


Graphene sealed in a pouch with electrolytes makes a flexible supercapacitor.

Image Credit: Ashley Jones / Clemson University

 

In Geneva, Switzerland, supercapacitors power public buses two kilometers from a 15-second charge, and interest in Clemson’s research is building.

“A national research and development enterprise in India is interested in the Clemson supercapacitors and visited the Clemson Nanomaterials Institute twice. Negotiations for manufacturing supercapacitors to power a bus are in progress,” said Rao, the Robert A. Bowen Professor of Physics in the College of Science.

Other potential applications of supercapacitors are far-reaching, from regenerative braking in hybrid and electric vehicles to providing the burst of power needed to adjust the direction of turbine blades in changing wind conditions.

Capacitors, unlike batteries, deliver a lot of power over a very short time. Batteries deliver less power, but they store much more energy. Batteries store energy through a chemical reaction: ions in lithium ion batteries move between negative and positive electrodes.

“While the chemical reactions hold much energy, the ion motion in batteries is rather slow, leading to low power,” said Podila, an assistant professor in physics and astronomy in the College of Science.

Supercapacitors overcome this by storing ions on the surface of nanomaterials electrostatically, like socks sticking to towels coming out of a dryer.

Graphene, the nanomaterial used by the Clemson team, is ultrathin, a million times thinner than a human hair. It’s stronger than steel, flexible and lightweight; a sheet the size of a football field would weigh less than a gram.

“The high-surface area of graphene provides space for ion storage (high-energy) and the ions are always on the surface ready to race (high power),” Podila said. “The problem, however, has been to effectively use the high surface area.”

Often, Podila said, ions can’t access some of the spaces in nanomaterials due to lack of connectivity. Also, the electrons within some nanomaterials may limit the total energy of a supercapacitor through an effect called “quantum capacitance”.

The Clemson team created microscopic layers of graphene with nanometer-sized pores, then sandwiched them together. The pores not only open new channels for ions to access all the spaces in graphene, but they also increase the quantum capacitance.

Creating the pores in specific configurations increased storage capacity 150 percent. Then the researchers introduced two different electrolytes whose ions were smaller than the pores; one by 20 percent, the other by 55 percent.

The effect was like spreading mayo on soft, light, porous bread; the electrolytes oozed into the pores.

“Testing showed the electrolytes with the larger ions did not increase the capacity, but the smaller ions travel through the pores into untapped parts of graphene. The result was a 500 percent increase in capacity,” Zhu said.

Furthermore, the graphene retained its electrical and material properties; the bread, soaked with mayo, didn’t fall apart.

Zhu and Childress also fashioned graphene into thin, flexible electrodes and inserted them into a flexible pouch. They filled the pouch with the electrolyte containing the smaller ions and sealed it, creating a lightweight, flexible supercapacitor that withstood more than 10,000 charge-discharge cycles without any loss in performance.

Source: Clemson

Tags:  Batteries  Clemson  Energy Storage  Graphene  Supercapacitor 

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Boron nitride-graphene hybrid for next-gen energy storage

Posted By Terrance Barkan, Tuesday, October 25, 2016

Layers of graphene separated by nanotube pillars of boron nitride may be a suitable material to store hydrogen fuel in cars, according to Rice University scientists.

The Department of Energy has set benchmarks for storage materials that would make  a practical fuel for light-duty vehicles. The Rice lab of materials scientist Rouzbeh Shahsavari determined in a new computational study that pillared boron nitride and graphene could be a candidate.

The study by Shahsavari and Farzaneh Shayeganfar appears in the American Chemical Society journal Langmuir.

Shahsavari's lab had already determined through computer models how tough and resilient pillared graphene structures would be, and later worked boron nitride nanotubes into the mix to model a unique three-dimensional architecture. (Samples of  seamlessly bonded to graphene have been made.)

Just as pillars in a building make space between floors for people, pillars in boron nitride graphene make space for hydrogen atoms. The challenge is to make them enter and stay in sufficient numbers and exit upon demand.

In their latest molecular dynamics simulations, the researchers found that either pillared graphene or pillared boron nitride graphene would offer abundant surface area (about 2,547 square meters per gram) with good recyclable properties under ambient conditions. Their models showed adding oxygen or lithium to the materials would make them even better at binding hydrogen.

They focused the simulations on four variants: pillared structures of boron nitride or pillared boron nitride graphene doped with either oxygen or lithium. At room temperature and in ambient pressure, oxygen-doped boron nitride graphene proved the best, holding 11.6 percent of its weight in hydrogen (its gravimetric capacity) and about 60 grams per liter (its volumetric capacity); it easily beat competing technologies like porous boron nitride, metal oxide frameworks and carbon nanotubes.

At a chilly -321 degrees Fahrenheit, the material held 14.77 percent of its weight in hydrogen.

The Department of Energy's current target for economic storage media is the ability to store more than 5.5 percent of its weight and 40 grams per liter in hydrogen under moderate conditions. The ultimate targets are 7.5 weight percent and 70 grams per liter.

Shahsavari said  adsorbed to the undoped pillared boron nitride graphene, thanks to weak van der Waals forces. When the material was doped with oxygen, the atoms bonded strongly with the hybrid and created a better surface for incoming hydrogen, which Shahsavari said would likely be delivered under pressure and would exit when pressure is released.

"Adding oxygen to the substrate gives us good bonding because of the nature of the charges and their interactions," he said. "Oxygen and hydrogen are known to have good chemical affinity."

He said the polarized nature of the  where it bonds with the graphene and the electron mobility of the graphene itself make the material highly tunable for applications.

"What we're looking for is the sweet spot," Shahsavari said, describing the ideal conditions as a balance between the material's surface area and weight, as well as the operating temperatures and pressures. "This is only practical through computational modeling, because we can test a lot of variations very quickly. It would take experimentalists months to do what takes us only days."

He said the structures should be robust enough to easily surpass the Department of Energy requirement that a hydrogen fuel tank be able to withstand 1,500 charge-discharge cycles.


SOURCE: PHYS.ORG 

Tags:  Boron Nitride  Boron nitride-graphene hybrid  Department of Energy  Energy Storage 

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Graphene Commercialization is closer than you think.

Posted By Terrance Barkan, Friday, October 21, 2016

When we conducted our survey of more than 400 graphene researchers, developers, producers and users earlier this year, less than 10% thought that graphene was a sustainable commercial market today. However, almost 2/3’s felt that graphene would develop into a sustainable commercial market in 6 years or less. (Survey 2016)

 

Based on the feedback and discussions at the Graphene Canada 2016 conference held in Montreal recently, graphene commercialization is a lot closer than most people are aware. 

 

Because graphene has properties that can be applied to such a wide range of potential applications, it is not always easy to see where this material is already being used or where development is most advanced. 

 

A graphene “killer application”?

 

There has been a lot of hype around graphene because of its superlative properties and the promise it holds for radical or revolutionary new applications, products and solutions.

 

There has been an equal measure of disappointment that it has not yet produced a “killer application”, a solution that solves a major problem that is possible because of graphene’s unique properties. 

 

The less sexy, but much more likely path to successful commercialization of graphene, lies in its use in more traditional materials like composites, thermosets (such as epoxies, polyurethane and polyester) and plastics. 

 

For example, Huntsman Advanced Materials (a division of the Huntsman Corporation, a publicly traded global manufacturer and marketer of differentiated chemicals with $10 billion in revenues) is working with graphene specialist firm Haydale to develop graphene enhanced ARALDITE® resins for composite applications. These products are used in the industrial composites, automotive and aerospace markets.

 

 

Huntsman's ARALDITE® resins are being enhanced using Haydale’s expertise in functionalisation of Graphene Nano Platelets (GNP’S) and other nano materials to create highly loaded master batches and to improve thermal / electrical conductivity and mechanical performance. The ultimate objective of the collaboration will be to commercialise graphene enhanced ARALDITE® resins for a range of applications in the

composites market.

 

It is telling that Huntsman, a company whose chemical products number in the thousands and are sold worldwide, has identified graphene as a critical new additive to enhance one of their most important industrial products. 

 

The global polymer market alone is worth at least $658 billion. Even if only a small percentage of this market begins using graphene as a standard additive to improve product performance, it will help support a viable market for graphene producers and formulators. 

 

Better Together

 

Additive Manufacturing, or 3D Printing, is a relatively new and exciting area of activity that is revolutionizing how objects are designed, prototyped and made. It is also a perfect example of how graphene can be used in combination with other traditional materials to create new capabilities and products. 

 

There are already three companies that offer graphene impregnated 3D printing filaments (Haydale, Graphene 3d Labs and Directa Plus) that are in turn letting creative designers develop products that are electrically conductive or that have superior physical properties (stronger, scratch resistant, better UV protections, etc.). 

 

Graphene is added to traditional polymers, paints and coatings to change their performance characteristics. Another company, NanoXplore is producing products as far ranging as specialty paints to fishing buoys (floats that are used in conjunction with fishing nets, crab pots, and related applications) that use graphene to make these products more robust and survivable in very harsh marine environments. 

 

 

What is unique about graphene is that it can make a significant improvement with very small loadings (as little as 1% or less) as compared to competing materials that may require as much as 25-30% loads to make significant performance differences. 

 

What this means is that although graphene materials are currently quite expensive per gram or kilogram, the very low loading levels makes graphene a competitive additive on a cost / benefit basis. 

 

The Future

 

It is difficult to overstate the enormous potential graphene holds to impact an almost unlimited range of industrial sectors, from water treatment to aerospace, from opto-electrical sensors to energy storage, from bio-medical applications to basic materials. 

 

So while university scientists and corporate research and development departments around the world continue to work on the more complicated problems where graphene might disrupt industries like semi-conductors or new generation photocells, graphene is proving its worth in somewhat mundane but equally important industrial materials applications. 

 

Tags:  3D Printing  Commercialization  Directa Plus  Fullerex  Graphene 3d Labs  Haydale  Huntsman  NanoXplore  Paints 

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Established Optical Society Sees the Light in Graphene

Posted By Dexter Johnson, IEEE Spectrum, Saturday, October 8, 2016
Updated: Thursday, October 6, 2016

SPIE—the international society for optics and photonics—has been a society set up to advance light-based technologies since 1955. In this role, it has offered its members conferences, news services and a range of different avenues for exchanging information on this quickly developing field.

As evidence of its commitment to staying ahead of the latest science and technologies in photonics and optics, SPIE has been offering conferences on the topic of graphene since 2009. SPIE has identified graphene and other two-dimensional materials as a key area of interest for its members because of the properties these new materials are offering in the field.

The Graphene Council certainly shares in SPIE’s interest in how two-dimensional materials, including graphene, will play a key role in optoelectronics and photonics, with our frequent coverage of these two fields. 

Now that SPIE has become one of our Corporate Members we took the opportunity to speak to Robert F. Hainsey, Ph.D., the Director of Science and Technology for SPIE to ask him about the role graphene is positioned to play in optics and photonics, how the market is developing and the role of SPIE as these developments evolve.

Q: Graphene has exhibited a number of appealing properties for applications within photonics and optoelectronics, so it’s clear to see why SPIE would become involved with the topic. But could you tell us a little bit about the evolution of how SPIE started getting involved in the topic of graphene? 

A:  SPIE has a long history of supporting the topic of graphene having launched a volunteer-inspired conference at our Optics + Photonics event held annually in San Diego as early as 2009.  The topic appears in a number of other SPIE conferences as well.  In 2014, Frank Koppens of ICFO delivered an excellent plenary talk on the subject at our Photonics Europe event in Brussels, and this led, in turn, to Frank Koppens and Nathalie Vermeulen of the B-PHOT team at Vrije Universiteit Brussel organizing and chairing a full-day workshop at this year’s Photonic Europe event on applications and commercialization of graphene.  We continue to look for methods to enable the community to best share results and exchange ideas in this rapidly evolving field.

Q: How is SPIE now approaching the topic, i.e. what sort of mediums are you using to get the message out about graphene? How do you see this information serving your members? 

A:  The information is disseminated in a number of ways.  Primary among these methods are our conferences which enable researchers to share and discuss the latest findings in the area of graphene and similar materials.  The work shared in those conferences is then packaged into proceedings and made part of the SPIE Digital Library so as to share the results with a wider audience.  We also have our journals where researchers can publish their results in a peer-reviewed medium.  The “SPIE Professional” magazine, the quarterly magazine for our members, has included articles in this area including one written by Frank Koppens earlier this year.  Naturally, we share news about graphene research on our News Room webpage, via Twitter and through our LinkedIn groups.  In terms of serving our members, we hope that this diverse set of methods of sharing information keeps our members informed on the latest work in the field and stimulates discussion among researchers to advance the field.

Q: There are a number of different applications within photonic and optoelectronics in which graphene has exhibited promise. In one of your more recent conferences on graphene, communication applications were identified as the most near-term. Has SPIE begun to get a better feel of how graphene applications within photonics and optoelectronics are developing commercially? And could you give us an outline of that development? 

A:  The workshop you refer to is a positive step towards moving graphene along the commercialization pipeline.  This workshop served to bring together academic and industrial researchers as well as entrepreneurs and start-up companies to discuss what is needed to move graphene from a laboratory to a production setting.  A look at the program for that event illustrates that large enterprises are investing in the research.  In addition, more start-up’s are appearing on the scene at various positions of the value chain.  Progress is being made on the road to full-scale production but there is still work to be done.

Q: Is SPIE involved with any of the standards bodies that are attempting to create industry standards for the material? Whether you are involved or not, does SPIE have a position on the role of materials standards as the material becomes increasingly commercialized?

A:  At this point we are not actively engaged in the work on developing standards outside of the presentations given in our conferences.  That said, one sign of research maturing and preparing to transition to a production environment is the discussion and adoption of standards.  Standards are oftentimes crucial since they provide a baseline for methods and performance by which the industry can determine capability and map progress.  SPIE supports standards development in other areas through methods such as providing meeting space for standards bodies at our events.  We would welcome dialogue with standards bodies in this area to determine if there is a way SPIE can more actively support that work.

Q: How do you see SPIE’s role in graphene education and providing information evolving as the field moves from the lab to the fab? Does the approach to disseminating information on a topic change as it moves from research to commercial interests? 

A:  Certainly the topic will continue to be a vibrant one in our conferences, our proceedings, the SPIE Digital Library, and our social media outlets.  SPIE events also include a set of industry sessions containing presentations, panel discussions, and networking opportunities focused on the commercial aspects of optics and photonics technologies.  This combination of conferences, publications, and industry sessions positions SPIE events to track the migration of the technology as it matures.  The flexibility we have within our events to include unique offerings such as the dedicated workshop on graphene commercialization at the SPIE Photonics Europe event earlier this year allows SPIE to tailor the forum to best serve the community.

Q: How does partnering with groups, such as The Graphene Council, help or contribute to your strategy in education and providing information on the topic of graphene?

A:  SPIE is an organization dedicated to serving the optics and photonics community.  Partnering with other organizations to further the sharing of information and enhancing the discussion around technologies not only helps SPIE meet its charter but, more importantly, enables the advancement of research, science, engineering and practical applications in these technologies.

Tags:  corporate members  optoelectronics  photonics  SPIE 

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Quality Is Timeless: How a 170-Year-Old Speciality Chemical Company Found Itself at the Forefront of Graphene

Posted By Dexter Johnson, IEEE Spectrum, Wednesday, September 28, 2016
Updated: Wednesday, September 21, 2016

 

When we think of graphene, we conjure up cutting-edge and emerging technologies that have a place in a sci-fi movie, and rightly so. But to make those dreams into reality it is coming down to a nearly two-century-old specialty chemical company to produce the building blocks. William Blythe, a 170-year-old inorganic specialty chemical and advanced materials company based in the UK, has established itself as one of the premier graphene oxide producers, enabling other companies to fabricate next-generation devices.

In May of this year, William Blythe added graphene oxide to its portfolio of products and ramped up production of the material to large lab-scale manufacturing, reaching kilogram capacity production. At this point, the company can manufacture up to 20 kg of powdered graphene oxide per annum with the aim of increasing to tonnage scale in the next 6 – 12 months.

To accompany the launch of this new product line, William Blythe has created its GOgraphene website at which you can order the company’s graphene oxide product, as well as find a blog that discusses the experience of launching a graphene-based business.

The Graphene Council took the opportunity of this recent business launch to talk to William Blythe’s Global Marketing & Sales Director, Marc C.G. de Pater, and in the interview below you can read how this company evolved and found itself at the forefront of  one of the most cutting-edge materials, graphene.

Q: Can you explain how a 170-year-old specialty chemical company like William Blythe found itself transitioning into the production of graphene oxide?

A: William Blythe was originally founded to support the textile industry, however over the last 170 years, William Blythe has transformed into an inorganic chemicals manufacturer, who is now on its way to becoming an advanced materials supplier. The expertise William Blythe has developed over the years, as well as its focus on innovation and product development, means the chemistry of graphene oxide fits very well with William Blythe core capabilities.

Q: Can you explain a little bit about the graphene oxide dispersions you produce and how these dispersions fit into the value chain that ultimately lead to products that may find their way into our store shelves?

A: William Blythe currently manufactures a high concentration graphene oxide dispersion at 10 mg/mL, or 1%. The manufacture of a high concentration is designed to maximize the options for graphene oxide users – the optimal concentration of graphene oxide is still being researched but is likely to be highly dependent on the application in question. Higher graphene oxide concentrations can lead to difficulty when diluting the dispersion, however William Blythe has developed a dispersion which can be very easily diluted, as demonstrated in this video: https://www.youtube.com/watch?v=xLixtvZRq0w.

In terms of the value chain, the nature of graphene oxide means William Blythe is positioned at the start. The graphene oxide dispersions offered allow William Blythe’s customers an opportunity to revolutionize the products they sell. Any graphene oxide, or graphene oxide derivative, that ends up on the store shelves is likely to be present in small concentrations, with consumers only aware of its presence through the enhanced properties they observe in the products they purchase.

Q: Why has your company struck upon graphene oxide production rather than single-crystal monolayer graphene? Was that because of what your customers were looking for or did it fit your business plans better in terms of both current production and how you see the market developing?

A: A combination of both – while the chemistry of graphene oxide synthesis fits very well with William Blythe expertise, there is also a strong argument for graphene oxide use over graphene in many situations. Graphene is a hydrophobic material, which means it can be very difficult to obtain good dispersions in various media. Graphene oxide, however, is highly hydrophilic and is reported to disperse very well in many polar solvents. By obtaining the required dispersion with graphene oxide and then reducing to graphene, graphene oxide may also allow users to gain the desired properties of graphene while achieving the dispersion characteristics needed.  William Blythe therefore believes graphene oxide has the ability to exist in the graphene market, employed in systems and applications where graphene would not be suitable.

Q: There seems to be an issue of wide disparity in the quality of graphene products. Is this something that will just be sorted out in the marketplace, or do you think standards will need to be instituted before this problem is fully addressed?

A: Graphene products are so new to the market it is understandable that there is so much variation in product quality. As more users investigate and adopt graphene or graphene oxide products into their applications, a consensus is likely to evolve naturally over what constitutes appropriate material for use. Formal standards may come into place at some point, however if graphene derivatives are already well established by this time it would be reasonable to expect these to take the approximate form of the informal standards already adopted. William Blythe will of course support the establishment of both informal and formal standards for graphene oxide where possible.

Q: What is the range of applications that your customers are using for the graphene oxide that you produce? And what is it about your product that makes them choose yours rather than others, i.e. price, quality, etc.?

A: William Blythe’s graphene oxide is of interest to a wide variety of applications. While it is not possible to disclose specific applications or customers, we can indicate that the range is broad enough to cover applications from membrane technology to advanced coating technology. The biggest attractions to William Blythe’s graphene oxide are its quality (dispersibility and number of layers) and the scale at which the material can be supplied. As a long established chemical manufacturer William Blythe is already planning to scale up manufacture to tonnage quantities. This, combined with a long history of manufacturing and supplying high quality chemicals gives customers confidence in William Blythe’s ability to support the launch of their technologies.

To support those still in research phases of graphene oxide application development, William Blythe recently launched a webshop, www.go-graphene.com , which sells research quantities of graphene oxide powder and aqueous dispersions. The feedback from this indicates the biggest draws are the competitive pricing and excellent dispersion characteristics.

Q: You are located near the University of Manchester where graphene was first discovered and a major research facility has been created. Has this proximity had an impact on your business? If so, in what way?

A: To an extent, the proximity of William Blythe’s headquarters to the University of Manchester has been of benefit. Members of both the commercial and technical teams at William Blythe have been able to attend meetings and conferences which may have been more difficult if the locations had been less convenient. These events have helped William Blythe to establish some of the understanding and network which are invaluable to the business today. Having said that, William Blythe is sufficiently committed to the development, manufacture and commercialization of graphene oxide that the same activities would have been pursued irrelevant of geography.

Q: Do you foresee William Blythe moving further up stream in the value chain by manufacturing products that employ your graphene oxide? Or will you remain producing dispersions of graphene oxides?

A: William Blythe intends to continue selling both graphene oxide dispersions and powders as well as any other relevant graphene derivatives which make sense in the future. Alongside these it is possible that William Blythe will offer products which fit in further down the supply chain. The volume and caliber of global graphene oxide research is so high at the moment it seems very likely there are other opportunities for William Blythe in the graphene derivative marketplace.

Q: Can you paint a picture of both William Blythe’s graphene business in the next 5 to 10 years and how the market will look more generally in those time periods?

A: Based on William Blythe’s market intelligence, it is anticipated that graphene products will be well established in the supply chain of several industries within the next 5 – 10 years. Naturally this means graphene oxide volume requirements will have risen and potentially the market price will be lowered. William Blythe expects to still be offering highly competitive pricing for high quality graphene oxide, with manufacture moving to a new dedicated graphene oxide plant. Early estimations predict William Blythe’s graphene oxide plant will have an annual production capacity of 10 tonnes.

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Tags:  graphene  graphene oxide  graphene producer  graphene production  specialty chemicals  University of Manchester  William Blythe 

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Electronics Applications for Graphene Still Hold Center Stage

Posted By Terrance Barkan, Wednesday, September 21, 2016

While membranes for separation technologies may be an attractive application for graphene, it will continue to be offered up as an alternative in electronic applications

 

The applications that have really spurred the huge amount of graphene and other two-dimensional (2D) material research over the years have come from the field of electronics. The fear that complementary metal–oxide–semiconductor (CMOS) technology is quickly nearing the end of its ability to ward off Moore’s Law, in which the number of transistors in a dense integrated circuit doubles approximately every two years, has been the spur for much graphene research.

 

However, there has always been the big problem for graphene that it does not have an intrinsic band gap. It’s a pure conductor and not a semiconductor, like silicon, capable turning on and off the flow of electrons through it. While graphene can be functionalized in a way that it does have a band gap, research for it in the field of electronics have looked outside of digital logic where an intrinsic band gap is such an advantage. 

 

In the stories below, we see how graphene’s unrivaled conductivity is being exploited to take advantage of its strengths rather than trying to cover up for its weaknesses

 

Graphene Comes to the Rescue of Li-ion Batteries

 

 

The role of graphene in increasing the charge capacity of the electrodes in lithium-ion (Li-ion) batteries has varied. There’s been “decorated graphene” in which nanoparticles are scattered across the surface of the graphene, and graphene nanoribbons, just to name a few of the avenues that have been pursued.

 

Another way in which graphene has been looked at is to better enable silicon to serve as the electrode material for Li-ion batteries. Silicon is a great material for increasing the storage capacity of electrodes in Li-ion batteries, but there’s one big problem: it cracks after just few charge/discharge cycles. The aim has been to find a way to make silicon so that it’s not so brittle and can withstand the swelling and shrinking during the charge charging and discharing of lithium atoms into the electrode material In these efforts, like those out of Northwestern University, the role of graphene has been to sandwich silicon between layers graphene sheets in the anode of the battery.

 

Now, Yi Cui from both Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory, who has been at the forefront of research to get silicon to be more flexible and durable for Li-ion batteries, has turned to graphene to solve the issue. 

 

Cui and his colleagues were able to demonstrate in research described in the journal Nature Energy, a method for to encasing each particle of silicon in a cage of graphene that enables the silicon to expand and contract without cracking. In a full-cell electrochemical test, the graphene-infused silicon anodes retained 90 percent of their charge capacity after 100 charge-discharge cycles. 

 

Previous attempts by Cui and many others to create nanostructured silicon has been very difficult, making mass production fairly impractical. However, based on these latest results, Cui believes that this approach is not only technologically possible, but may in fact be commercially viable.

 

The process involves coating the silicon particles with a layer of nickel. The nickel coating is used as the surface and the catalyst for the second step: growing the graphene. The final step of the process involves using an acid on the graphene-coated silicon particles so that the nickel is etched away.

 

“This new method allows us to use much larger silicon particles that are one to three microns, or millionths of a meter, in diameter, which are cheap and widely available,” Cui said in a press release. “Particles this big have never performed well in battery anodes before, so this is a very exciting new achievement, and we think it offers a practical solution.”

 

While a practical manufacturing approach was much needed, the technique also leads to an electrode material with very high charge capacity.

 

“Researchers have tried a number of other coatings for silicon anodes, but they all reduced the anode’s efficiency,” said Stanford postdoctoral researcher Kai Yan, in a press release. “The form-fitting graphene cages are the first coating that maintains high efficiency, and the reactions can be carried out at relatively low temperatures.”

 

Graphene Provides the Perfect Touch to Flexible Sensors

 

Flexible sensors are the technological backbone of artificial skin technologies. The idea is that you can impart the sense of touch to a flexible sensor, making it possible to cover a prosthetic device for either a robot or replacement limb so it can feel. Creating materials that tick the boxes of flexibility, durability and sensitivity has been a challenge. Over the years, researchers have increasingly turned to nanomaterials, and graphene in particular, as a possible solution. 

 

Researchers at the University of Tokyo have found that nanofibers produced from a combination of carbon nanotubes and graphene overcomes some of the big problems facing flexible pressure sensors: they’re not that accurate after being bent or deformed. The researchers have suggested that the flexible sensor they have developed could provide a more accurate detection breast cancer.

 

In research described in the journal Nature Nanotechnology, the scientists produced their flexible sensor by employing organic transistors and a pressure sensitive nanofiber structure.

 

The researchers constructed the nanofiber structure using nanofibers with diameters ranging between 300 to 700 nanometers. The researchers produced the nanofibers by combining carbon nanotubes and graphene and mixing that into a flexible polymer. The nanofibers entangled with each other to form a thin, transparent structure.

 

In contrast to other flexible sensors in which the striving for accuracy makes the sensors too sensitive to being deformed in any way, the fibers in this new flexible sensor does not lose their accuracy in measuring pressures. These fibers achieve this because of their ability to change their relative alignment to accommodate the bending. This allows them to continue measuring pressure because it reduces the strain in individual fibers.

 

Tunable Graphene Plasmons Lead to Tunable Lasers


 

  

A few years ago, researchers found that the phenomenon that occurs when photons strike a metallic surface and stir up the movement of electrons on the surface to the point where the electrons form into waves—known as surface plasmons—also occurs in graphene

 

This discovery along with the ability to tune the graphene plasmons has been a big boon for the use of graphene in optoelectronic applications. Now research out of the University of Manchester, led by Konstantin Novoselov, who along with Andre Geim were the two University of Manchester scientists who won the Nobel Prize for discovering graphene, has leveraged the ability of tuning graphene plasmons and combined it with terahertz quantum cascade lasers, making it possible to reversibly alter their emission. 

 

This ability to reversibly the alter the emission of quantum cascade lasers is a big deal in optoelectronic applicatiopns, such as fiber optics telecommunication technologies by offering potentially higher bandwidth capabilities.

 

“Current terahertz devices do not allow for tunable properties, a new device would have to be made each time requirements changed, making them unattractive on an industrial scale,” said Novoselov in a press release. “Graphene however, can allow for terahertz devices to be switched on and off, as well as altering their state.”

 

In research described in the journal Science, were able to manipulate the doping levels of a graphene sheet so that it generated plasmons on its surface. When this doped graphene sheet was combined with a terahertz quantum cascade laser, it became possible to tune the transmission of the laser by tuning the graphene plasmons, essentially changing the concentration of charge carriers.

 

Graphene Flakes Speed Up Artificial Brains


 

 

Researchers out of Princeton University have found that graphene flakes could be a key feature in computer chips that aim at mimicking the function of the human brain. 

In the human brain, neurons are used to transmit information by passing electrical charges through them. In artificial brains, transistors would take the place of neurons. One approach has been to construct the transistors out of lasers that would turn and off and the time intervals between the on and off states of the lasers would represent the 1s and 0s of digital logic.

 

One of the challenges that researchers have faced in this design is getting the time intervals between the laser pulses down to picosecond time scales, one trillionth of a second.

 

In research described in the journal Nature Scientific Reports, the Princeton researchers placed graphene flakes inside a semiconductor laser to act as a kind of “saturable absorber,” that absorbed photons and then was able to emit them in a quick burst. 

 

It turns out graphene possesses a number of properties that makes it attractive for this application. Not only can it absorb and release photons extremely quickly, but it can also work at any wavelength. What this means is that even if semiconductor lasers are emitting different colors, the graphene makes it possible for them to work together simultaneously without interfering with each other, leading to higher processing speeds.



Tags:  Batteries  Electronics  Flexible electronics  Lasers  Li-ion  Sensors 

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The Graphene Supply Chain is Maturing, But It Still Needs Some Guidance

Posted By Dexter Johnson, Friday, August 26, 2016

An interview with the Tom Eldridge, Director of UK-based Fullerex Limited

 

One of the big stories for graphene going forward is the continued maturation of its supply chain. 

 

Producers of graphene are getting better at understanding not only how to make graphene more cost effectively and with a higher quality, but also are figuring out what kind of graphene to make. The intermediaries—the companies that functionalize graphene and have the knowhow to disperse it in a material matrix—are gaining a more defined role in the supply chain. And finally, the companies who are trying to make something out of graphene, like a tennis racquet, or a supercapacitor, are developing a greater sense of trust in the supply chain.

 

One company that has been at the forefront of securing that supply chain is UK-based Fullerex Limited. Fullerex helps both ends of the supply chain work out how unmet needs can be satisfied. 

 

In this interview we discuss with the director of Fullerex, Tom Eldridge, the nature of the company’s business and how sees the market developing over the short term.

 

Q: For people that come to The Graphene Council website, they may be familiar with Fullerex’s pricing index and your Bulk Graphene Pricing Report, but that is only a small part of your business, correct? Could you describe what service Fullerex provides and to whom?

 

Our main activity as a business includes providing a brokering service for advanced materials and technology, specializing in nanomaterials and nano-intermediates. The company has twenty partners worldwide, which it represents on an agency basis. These firms include producers of various nanomaterials such as novel carbon allotropes for example fullerenes, carbon nanotubes and graphene and also technology solutions providers related to the downstream processing of these materials.

 

Fullerex supports these strategically placed partners in developing the market for their products and technologies by identifying suitable collaborators and potential early adopters in industry. Typically we help end-users looking to address an unmet need through material innovations. We are able to generate interest in trialing and testing certain nanomaterial types and key enabling technologies by making introductions between the right people.

 

The annual graphene pricing report forms part of our ancillary services. Fullerex first released the Bulk Graphene Pricing Report in 2014, which has now seen three editions with continual updates each year to the data and analysis contained within the pricing study.

 

Q: It would seem then that you enable both graphene producers and the end users to better understand what kind of graphene might best work for each potential application, correct?

 

Our value proposition is to accelerate growth in the market for materials such as graphene. This not only entails understanding the potential applications for graphene and finding end-users that are committed to materials R&D but yes, also having knowledge of the relevant types of graphene for those uses. Producers themselves have differing degrees of expertise between them when it comes to certain application areas.

 

A core role of Fullerex is to select the technical expertise and materials from our range of partners to best meet the requirements of a given end-user. In addition, a critically important component of pre-screening these opportunities involves understanding the cost implications and whether the use of graphene makes sense for the target market. These technical and commercial considerations combined are at the forefront of the decision making and strategy for our business.

 

Q: What range of applications for graphene do you offer for this kind of service? Could you provide some examples of the kind of information that it is important for both graphene producers and end users to understand before the material can be effectively applied?

 

Graphene can be very broadly thought of as supplied in two main material forms: as a powder or as a continuous thin film. Fullerex focuses very much on the former type of product. By adding the graphene powder to various base materials you can improve properties of the base material or add properties that perhaps were not there before, creating multifunctional materials.

 

The markets for this type of graphene include polymers and composites, coatings, inks, lubricating oils, construction materials etc. For an effective application it is important to establish what performance goals the end-user is looking to achieve and for what purpose, what is the price sensitivity of the target market and what are the potential quantity demands if the new product is successfully developed. Essentially, is there a good business case?

 

Q: Where is the biggest gap in information? Do the producers not understand how their product should be targeted or are the end users lacking an understanding of the kind of graphene that will work for them?

 

There are information gaps on both sides. Many potential end-users are simply not aware of all the potential applications for graphene and remain unconvinced until a producer can demonstrate clear advantages with a product that can be easily trialed, that is compatible with existing manufacturing processes and does not require significant investment to implement (by acquiring new technical capabilities in terms of equipment or expertise). To get to this stage takes development work which some end-users may be prepared to fund to generate unique IP but for the most part, it is expected of the producer to build that capability internally or through its close network and partnerships.

 

Q: Further to the previous information gap question, how do you see the investment community at this point when it comes to graphene? Are you explaining what it is and what it can do for them, or are you discussing investment opportunity points with them?

 

Our client base is exclusively comprised of commercial enterprises and not members of the investment community. However, as a general comment, one aspect of business strategy for graphene companies which may have an impact in terms of attracting investors is the potential to position the business either in terms of offering a product geared towards a particular market or offering a platform technology with wider scope than just one application.

 

This comes back to expertise, since to focus on one application area in particular may make it quicker and easier to develop those applications and demonstrate a clear advantage to potential customers but it also narrows the addressable market for the business and therefore may remain interesting only to certain investors looking in that area.

 

Q: At this point, do you have a breakdown of the graphene market, i.e. how much graphene is being sold worldwide and how that amount breaks down into material types and appropriate applications?

 

The analysis that we have carried out for our pricing report extends to including some top line figures about the market in terms of the overall market size and segmentation between bulk graphene and graphene thin films.

 

Q: As this market stands now, what application area do you see as being the most successful today? And where do you see the most promise in the near term of the next five years?

 

The first commercial applications have arrived in the form of sporting goods ranging from tennis rackets, skis, bicycle tires and sports clothing. The criticism often laid against these examples is that consumer products can be marketed successfully on perceived advantages rather than necessarily offering any demonstrable improvement.

 

Industrial applications on the other hand are more uncompromising and certainly demand an obvious cost-benefit. As such there are fewer examples of this kind to point towards. Industry uses are starting to emerge however and I see polymer applications being the area, which will bring the majority of uses for graphene over the next few years, in plastics, composites, coatings and 3D printing in particular.

 

Q: Based on your work, what would be some of the key points of advice you would pass on to producers and end users to start exploiting graphene to its full potential?

 

Collaboration is key, whether that is between graphene producers and early adopters, enabling technology companies, manufacturing partners, or academia. Applications cannot be developed unless there are all the right elements of the value chain in sync. Moving towards large-scale adoption of the technology requires consistency in supply and this is one of the reasons there is such a strong focus on characterization and standards across the emerging industry. This is an international effort.

 

Finally, graphene has such unique properties with potential to make a positive impact in economic terms and societal terms across so many areas that it is important to engage as many relevant organizations as possible to build the community of stakeholders.

 

Tags:  Commercialization  Fullerex  Graphene  Products 

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