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Simple Approach for Producing Pure Graphene Opens Up Applications

Posted By Dexter Johnson, IEEE Spectrum, Thursday, May 4, 2017

 

Image: U. Landman and B. Yoon

One of the key challenges in developing next-generation electronics based on graphene has been the costly and complicated processes of getting single-layers of graphene. To produce these pure versions of graphene that are suitable for the electronic applications the most common methods have been either mechanical exfoliation, in which one-atom thick sheets of graphene are pulled away from graphite, or Chemical Vapor Deposition (CVD) in which a carbon precursor is heated with the carbon condensing on a substrate such as copper or silicon. 
 
When solution-based techniques have been used in the past, the graphene is not in the form that has been proven to possess the material’s remarkable properties, like conductivity.

 

Now an international team of researchers working together through the Georgia Institute of Technology is reporting on a new method for producing graphene that uses a gradual heating process of a single precursor—ethylene—to very high temperatures. The researchers expect that this simple and an inexpensive approach to producing graphene could expand its applications.

In research described in the Journal of Physical Chemistry C, the researchers used ethylene, which is the smallest alkene molecule, containing just two atoms of carbon, and gradually heated it to 700 degrees Celsius, to create pure layers of graphene on a rhodium catalyst substrate.

“Since graphene is made from carbon, we decided to start with the simplest type of carbon molecules and see if we could assemble them into graphene,” explained Uzi Landman, a professor at Georgia Tech who headed the theoretical component of the research, in a press release. “From small molecules containing carbon, you end up with macroscopic pieces of graphene.”

This work is not the first time that scientists have attempted to produce graphene by using hydrocarbons like ethylene as a precursor. Those attempts failed, producing little more than carbon soot rather than a structured graphene.

The researchers were undeterred by previous failures because theoretically this stepped heating approach of ethylene should lead to the formation of a series of structures when the hydrogen atoms break away from the ethylene molecules and the carbon atoms self-assemble into the honeycomb pattern of graphene.

To overcome the previous lack of success, research groups in Germany and Scotland instead of simply heating the ethylene heated the material with a rhodium substrate in a vacuum. What they found was that the ethylene adsorbed onto the rhodium catalyst, changing through coupling reactions to create one-dimensional structures of polyaromatic hydrocarbons.

When these structures are heated further they go from being one-dimensional to two-dimensional materials. Just before the graphene is finally formed, the researchers observed round disk-like clusters containing 24 carbon atoms spread out to form the lattice structure of graphene.

“The temperature must be raised within windows of temperature ranges to allow the requisite structures to form before the next stage of heating,” Landman explained. “If you stop at certain temperatures, you are likely to end up with coking.  All along the way, there is a loss of hydrogen from the clusters. Bringing up the temperature essentially ‘boils’ the hydrogen out of the evolving metal-supported carbon structure, culminating in graphene.”

Currently, in its final form the resulting graphene structure is adsorbed onto the catalyst. While for this final structure is satisfactory for the demonstration, for other applications the graphene will need to be removed from the substrate.

Landmann added: “This is a new route to graphene, and the possible technological application is yet to be explored.”

Tags:  electronic applications  Georgia Institute of Technology  graphene manufacturing  mechanical exfolation 

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Who Will Win the Race for Clean Water Technologies Using Graphene?

Posted By Dexter Johnson, IEEE Spectrum, Monday, April 10, 2017

 

Image: University of Manchester

Graphene can take on at least three distinct technology approaches for producing clean water, according to Miao Yu, a professor at University of South Carolina and founder of UK-based G2O Water Technologies Ltd. as he explained to The Graphene Council last year in a interview.

In that interview, Yu said the first approach of the three is to use graphene in the creation of functional coatings. The second approach involves producing lamellar structures with nano-channels, which requires using fine layers of alternating types of materials. G2O Water is doing a bit of both of these approaches by creating a functional coating that can be applied to today’s polymer water membranes, and also creating scalable fabrication of lamellar structures of graphene oxide.

The third approach is to allow selective permeation through structural defects of single-layer graphene or graphene oxide. A group at MIT is probably the most notable example of the use of this approach in a technique they reported on three years ago. 

All of these approaches to using graphene in water applications is taking on increased interest after news came out last week that researchers from the University of Manchester have developed a graphene oxide membrane that in addition to filtering out small particles has small enough pores that it can filter out salt ions. This approach, which was published in the journal Nature Nanotechnology, falls into the approach taken by the MIT researchers.

The Manchester researchers have managed to overcome a key problem in this approach when the membranes swell up after being immersed in water for some time, allowing smaller particles to continue to pass through.

“Realization of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology,” said Rahul Nair, a professor at the University of Manchester and one of the co-authors of the research, in a press release. “This is the first clear-cut experiment in this regime. We also demonstrate that there are realistic possibilities to scale up the described approach and mass produce graphene-based membranes with required sieve sizes.”

Of course, the imprimatur of the University of Manchester on anything to do with graphene suddenly makes this latest research noteworthy. However, the final arbiter on whether this graphene approach or the others like it for either desalinating or purifying water remains squarely on the industry.

While the mainstream press--like the BBC--has seemingly ignored all other efforts for using graphene in the desalination or purification of water--setting up the Manchester research as a kind of first in the field--the trade press has been a bit more circumspect.

The publication Water & Wastewater International (WWi) has a pretty thorough assessment of the latest Manchester research and how it stacks up to other efforts for desalinating water using graphene.

While WWi remains pretty sanguine about the general prospects of using graphene for water desalination, they get some expert opinions that characterizes this latest research as something of a long shot at this point.

Graeme Pearce, principal at Membrane Consultancy Associates (MCA) told WWi in an interview: "The development at the University of Manchester aims to produce a membrane with a highly controlled character, free from defects. Given the materials used, longevity should also be good. The challenge will be whether the membrane can be effectively used with the current form factor (the spiral wound element mounted in series in long pressure vessels) and using current process design concepts.

"Alternatively, the membrane might be better exploited by a completely different approach to process design, which would be high risk and slow to introduce, but might have a much greater long term impact if the improved membrane can be exploited more efficiently."

He added: "The key issue would be to demonstrate both performance and longevity in the first instance and then establish what features of the current approach to desalination plants limit the benefits of a new membrane and what can be done to remove these impediments."

It turns out that the technology of G2O Water technologies might have the inside track at this point, according to Pearce.

He added: "This preserves the form factor and should be more easily adopted by the industry. The development is still early stage and the longevity of the coating has yet to be established, but the approach appears to be promising and initial results on performance enhancement have been encouraging. This is more likely to allow a radical optimization of existing practice rather than the potentially more revolutionary but higher risk development from Manchester."

Tags:  G2O Water Technologies  graphene oxide  membranes  University of Manchester  water desalination  water purification 

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Imagine IM Reimagines Graphene Business Strategies

Posted By Dexter Johnson, IEEE Spectrum, Friday, March 31, 2017

 

 

Australia-based Imagine Intelligent Materials (Imagine IM) was launched back in 2014 by a divergent group of scientists, engineers and business leaders that recognized that the time was right for launching a business that made devices from graphene.

A couple of the keys to Imagine IM’s business strategy have been to control their own supply chain and to produce devices that really depended on graphene rather than just lending a marketing tag to a product that was not improved by graphene. To do this, they opened their graphene pilot plant in Geelong, Victoria, Australia in August 2016 with a capacity of up to 10 metric tonnes of graphene per year.

This plant will provide the material that the company will use to create smart materials for detecting stress, temperature and moisture. These smart materials can be offered as “drop-in” solutions for large-scale manufacturing processes.

As an example of this, Imagine IM has partnered with Geofabrics Australasia to develop a leak location system that employs “a conductive non-woven geotextile in between two non-conductive membranes to allow the detection of defects in the membrane.” 

In a the Q&A provided below, we speak to Imagine IM’s CEO, Chris Gilbey, to find out more about the relationship between their graphene production and device manufacturing and learn about how he sees the nascent graphene industry shaping up over both the short- and long-term.

Q: You are involved in both the manufacturing of graphene—with a production capacity of 10 metric tonnes per year—and using graphene to make smart materials for sensing temperature, stress and moisture. I was wondering if you could breakdown your business with a bit more detail. Are you actually manufacturing devices for sensing, or are you producing master batches for other device manufacturers to make the devices?

Our view is that that graphene is not a product. It’s a means to make products. And you can't make the appropriate graphene unless and until you understand what the end product application is going to be, what the functionalization requirements are, what the plant and product requirements are, etc.  We want to deliver solutions...and it happens that graphene turns out to be a highly efficient way to achieve some things as long as you understand what the rules of the supply chain are that you want to work in.

Q: Could you describe the graphene that your plant produces? What is the quality of the graphene and what applications is it suited for?

We make multilayered graphene in the plant we have built. But frankly it’s not about the graphene. It’s about the process of developing a masterbatch material. The quality is the wrong question to ask frankly. Quality with respect to what criteria? If you measure quality in terms of size of nanoplatelets and you make platelets that are 75 microns in size hypothetically and the application requires you to make graphene that that will fit into a 50-micron fiber then you have a mismatch. Quality at this point in the evolution of graphene applications is a largely misunderstood proposition in my view.

I believe that in any industry you always start with the customer need. Quality is less important than functionality and price. Rolls Royce might be a bench mark of quality in the automotive sector or perhaps they may be more correctly a benchmark of luxury. What then is quality? Back in the early days of GM the board of the company would have argued that they made quality autos. But Alfred Sloane and also Peter Drucker would perhaps have argued that they had incomplete information from the field and, as a result, made determinations that were entirely out of sync with reality!

What we focus on is developing fit-for-purpose graphene at the lowest possible price, and at a location that meets the supply chain objectives of customers. At this point in time, our focus is on developing appropriate levels of conductivity in materials—in particular industrial fibers and fabrics. Conductivity is a pre-requisite of delivering sensing.

Q: Is the idea that your 10 metric tonne production capacity will fulfill your own internal needs for master batches or device manufacturing? Or do you intend to sell some of that production to other companies?

No point in selling graphene to anyone. Not enough sustainable margin plus volume to make it into a business. Graphene as a feedstock material is in the early stages of being commoditized. More people will bring production on line, at lower prices, and many of the players will get into a race to the bottom on price. After all, there are already Taiwanese and Chinese companies boasting of >100 tonnes per year capacity. That is not the business we are in.

Q: Do you have a five-year plan on that production capacity? In other words, do you foresee that will be meeting your market needs in five years or will you have to increase capacity? What are your current operating rates?

Short answer is that if our vision was to only need to produce 10 tonnes per year in five years, we would have already died and gone to heaven. 10 tonnes will satisfy one product sku in Australia. We are in discussions currently to set up a plant in the US that will get us started in that market - just started!

The answer is in any event that you have to have distributed manufacturing that is close to your end use application in order to be part of mass manufacturing supply chains. I would anticipate market needs in tonnages greater than 100 tonnes for that one sku in a global scenario. At the end of the day, we want volume, volume, volume.

Q: How did you come to focus on the smart materials market? Was it something inherent in the graphene that you produced that lent itself to this application area? Or did you see an unmet need in the marketplace and then tailored your graphene for this use?

Actually the strategy is to reframe the concept of unmet needs and look at it through an economic lens. The intention is to become a disruptive player in mass manufacturing in the first instance and to be able to make smarter products at lower prices where we can positively impact the economics of products; i.e. there may be a need that is currently met, but if we can make a solution that radically changes the economics we get to win.

Q: As one of the early graphene manufacturers, what do you see lacking in today's graphene supply chain, i.e. lack of industry standards, poor understanding among users of graphene’s capabilities, etc.?

Simple answer: Certification. Industry standards are going be like legal structures for copyright. They will always trail the reality of disruptive technology. Why is Netflix such a powerhouse now? Because they figured that most people would prefer to purchase content legally than steal it, and the studios couldn't get their heads out of their backsides.

However, most manufacturers don't just want for there to be a QA process. They have to have it in order to be able to de-risk their businesses. At the center of our business is the concept and the reality of certification. It’s proprietary, just as the Dolby Labs certification process is, and the WL Gore certification process is. We have just started, funded in part by a federal government grant in Australia, a Graphene Supply Chain Certification and Research Facility at Swinburne University in Melbourne. This is the first of its kind worldwide and will enable us to look at the impact of the almost infinite permutations of changes to materials that take place in the nano-domain.

Q: What sort of movements and developments do you expect to see in the graphene marketplace over the next 5-10 years? Will applications become more narrow and defined or broader and dispersed? Will digital electronics become a reality or an afterthought? Any thoughts on the future?

All I can say to that is that I firmly believe that applications that utilize nanomaterials will be ubiquitous in 10 years. Equally, I think there will be a massive shake out in the marketplace. One company in the UK is rolling up a bunch of the early-stage graphene start-ups that couldn't get product to market. I think that the Gartner hype curve is playing itself out as one would anticipate and there will be a tremendous amount of consolidation over the next few years.

Companies like Samsung will be dominant in electronics applications as they pertain to consumer electronics (along with several Chinese companies). The bottom line for me is that the people who focus on selling graphene will be marginalized over the next ten years. Mass manufacturing is where the money will be. 3D printing will be a small business for quite a while yet. The big chemicals companies and the PE companies that have a focus on chemicals and advanced materials will remain the smartest guys in they room—meaning that BASF, DuPont, and similar will stand on the side lines and will pick off the little guys as they run into trouble. And somewhere in there a Google will emerge that redefines the whole sector...and a bunch of shareholders will make a lot on the way through and a bunch will lose out... And the Chinese may come through as the dominant country in the space... And hopefully we will find ourselves on the positive side of the ledger...

The bottom line is that anyone who thinks that they are going to make money out of graphene from applications that use only small amounts will find that their business models are unsustainable. Mainly because it is in no one's interest (who is a supplier) to sell small quantities of a material except with a giant margin and that doesn't incentivize you to develop scale....

I find this area of human enterprise to be utterly fascinating! And if you read for instance, what Danny Kahneman did, when he was asked to advise the Israeli army and air forces on how to identify future leaders and how his advice ran absolutely 180 degrees contrary to what was in place at the time, and the success of his research and approach, to me that is what is going to be needed conceptually to build an industry!

Tags:  graphene  graphene production  smart materials 

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Graphene-Based Transistor Opens Up Terahertz Spectrum

Posted By Dexter Johnson, IEEE Spectrum, Friday, March 10, 2017

Terahertz radiation represents a range of the electromagnetic spectrum extending from the highest frequency radio waves to the lowest frequency infrared light. While many attempts have been made to create compact, solid-state devices that can harness it, terahertz radiation has proven difficult to exploit.

However, if such devices can be developed that can tap into the terahertz spectrum, we could see it make a big impact in non-invasive imaging in industry, medicine and security where they are less harmful than X-rays and because of the shorter wavelength and provide sharper images than those produced by microwaves.

Graphene has begun to show some real promise in terahertz devices for everything from wireless communications to improved quantum cascade lasers that can reverse their emission, offering a complete change to fiber optic telecommunications. 

Now researchers at the University of Geneva (UNIGE), working with the Federal Polytechnic School in Zurich (ETHZ) and two Spanish research teams, have developed a technique, based on the use of graphene, that can potentially control both the intensity and the polarization of terahertz light very quickly

The researchers believe that their research, which is described in the journal Nature Communications, could lead to the development of practical uses of terahertz waves to imaging and telecommunications. They key to their development was the fabrication of a graphene-based transistor adapted to terahertz waves.

Because the interaction between terahertz radiation and the electrons in graphene is very strong, the researchers believed that it should be possible to use graphene to manage terahertz waves. With this graphene-based transistor, the researchers believe this kind of control over a complete range of terahertz frequencies is now possible.

"By combining the electrical field, which enables us to control the number of electrons in graphene and thus allows more or less light to pass through, with the magnetic field, which bends the electronic orbits, we have been able to control not just the intensity of the terahertz waves, but also their polarization," said Jean-Marie Poumirol, a member of the UNIGE research team and the first author of the study, in a press release. "It is rare that purely electrical effects are used to control magnetic phenomena."

The researchers envision the graphene-based devices being used in communications and imaging.

"Using a film of graphene associated with terahertz waves, we should be potentially able to send fully-secured information at speeds of about 10 to 100 times faster than with Wi-Fi or radio waves, and do it securely over short distances," explained Poumirol.

 The initial imaging applications are thought to be in security. Alexey Kuzmenko, team leader of the research at UNIGE added: “Terahertz waves are stopped by metals and are sensitive to plastics and organic matter. This could lead to more effective means of detecting firearms, drugs and explosives carried by individuals, and could perhaps serve as a tool to strengthen airport safety."

Tags:  communications  fiber optics  imaging  security  terahertz  transitor  wireless 

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Graphene Interlayer Fixes the Schottky Diode

Posted By Dexter Johnson, IEEE Spectrum, Friday, February 10, 2017

Schottky diodes are the grand daddy of semiconductor devices. They are formed when a semiconductor material is combined with a metal and the junction between the two materials creates the Schottky diode. Despite being around since forever, it’s never been quite possible to make them into an ideal diode in which when a voltage is applied it acts as conductor and when the voltage is reversed it serves as a insulator.

Now researchers at the Ulsan National Institute of Science and Technology (UNIST) in Korea have been able to produce the ideal version of the Schottky diode by inserting a graphene layer between the semiconductor and the metal, and in the process have eliminated 50 years of head scratching over this issue. 

In research described in the journal Nano Letters, the UNIST researchers discovered that graphene serves to prevent the intermixing of atoms that occurs when the semiconductor and metal are touching each other directly.

“The space between the carbon atoms that make up the graphene layer has a high quantum mechanical electron density and therefore no atoms can pass through it,” said Kibog Park, a professor at UNIST and co-author of the paper, in a press release. “Therefore, by inserting the graphene layer between metal and semiconductor, it is possible to overcome the inevitable atomic diffusion problem.”

While the research solved this problem, it also confirmed a prediction that it didn’t matter what kind of metal was used to form the Schottky junction; the performance does not change significantly.

The applications for Schottky diodes are pretty broad, but the main use is that of a rectifier, which converts alternating current (AC) to direct current (DC). But so many electronic devices use these diodes that this research is expected to resolve what has been a long-standing issue within the electronic industry.

Tags:  electronics  graphene interlayer  metal  rectifier  Schottky diodes  semiconductor 

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NanoXplore Brings Unique Perspective to Graphene Production

Posted By Dexter Johnson, IEEE Spectrum, Thursday, January 26, 2017

 

After Montreal-based NanoXplore launched in 2011, its initial business was contract research in the field of carbon-based technologies. But its identity as a contract R&D company changed in 2014 when it filed a series of patents focused on graphene production.

As the company further developed its technology since then, the main focus of the company has become providing graphene-enhanced polymers for plastics that have enhanced electrical, thermal and mechanical properties.

The company website suggests that these graphene-based polymers have a variety of applications, ranging from photovoltaics to supercapacitors

We wanted to get to know how a relatively new company that started out as an R&D contractor evolved into a graphene-enhanced polymer manufacturer and how they now see the downstream market for their product. To do that, we took the opportunity of NanoXplore becoming a corporate member of The Graphene Council to talk to the company’s chief operating officer, Paul Higgins, and here is that interview.

Q: NanoXplore started out as an R&D contractor in carbon-based technologies. How is it that the company was able to file a patent in graphene production patent just two years after being formed? Were you always doing research in this area, or did you make a concerted effort to find a place in the graphene market?

Working with other carbon-based materials, especially CNTs, it became evident that many commercialization challenges were due to the production processes. The processes had been developed in research environments and were not designed from the ground up with an industrial mindset. We focused from the beginning on low cost, high-yield processes, using existing capital equipment, and with no pre- and post-processing. For example, our graphene production process functionalizes the graphene in-situ, avoiding costly functionalization post-processing for most applications. We were also very cognizant of the need for sustainable, “green” processes; our patented process is water-based, uses no strong acids, and no organic solvents.

A key insight underpinning our patents is that high energy and strong chemical processes create many downstream problems in graphene production. High-energy processes are inefficient and create defected planar structures, resulting in graphene with poor electrical and thermal benefits, in turn requiring high, non-economic loadings of graphene in nanocomposites.  Strong chemical processes require complicated post-processing and recycling processes to be cost effective and require very tightly controlled production environments, adding costs.

Once we had established the frame of potential solutions based upon the above, developing our new technology platform was relatively straightforward.

Q: Were you looking to enter a particular niche of the graphene supply chain or did the process you came up with dictate somewhat the point in the supply chain that you now occupy?

Our process is high yield, large volume, low cost, and produces graphene powder with very high quality. This allows us to target mass industrial material markets such as polymers, markets requiring large volumes of material. And due to the quality of our graphene, we can provide significant benefit to industrial materials at low loadings and viable price points.

Of course, the graphene must be effectively mixed into the polymer matrix. To do this we have developed production processes for the manufacture of graphene-enhanced plastic masterbatches. These masterbatches, which we have been manufacturing and selling since early 2016, are the perfect form factor for the plastic industry. Plastic formers, such as injection and blow molders, and compounders are very comfortable with masterbatches and easily incorporate them into their existing processes.

Q: Do you see the company evolving to develop products further up the supply chain? For instance, it appears you’re involved in energy storage technologies enabled by graphene. Is this where you see your business moving or do you see this is just diversification of your portfolio?

NanoXplore is focusing our current commercial efforts on graphene-enhanced polymers. We see this as a large market, hungry for innovative materials, where our graphene has a strong competitive advantage.

We also have a patent on a unique graphene-graphite composite material that is useful for energy storage applications. This material was the impetus for our original research in the energy field. This initial research showed great promise and leads us into development of a range of materials for Si-graphene anodes and S-graphene cathodes.

From our current polymer efforts and the emerging energy storage materials, we see a sustainable growth model for the company. Our core research efforts develop graphene-based technologies for a target market, and then transition to product development. During the transition, we will develop technologies for the next target industry. And repeat. Graphene is so broadly applicable that we foresee being able to continue in this vein for some time.

Q: How does your company envision the landscape for the graphene market evolving over the next five years, i.e. are there particular markets that will be winners and losers, what applications are not being sufficiently targeted, etc.?

The graphene market has changed significantly over the last three years. Three years ago the challenge for end users was to obtain decent material, in volume, at a reasonable price. Today there are several producers, including NanoXplore, producing large volumes of good quality graphene. Prices per kg for high quality graphene have fallen during this period from $30,000 kg to $100 Kg and are set to fall to $30 kg over the next five years.

[NB: Above and subsequent comments pertain to high quality - low defect, functionalized few layer graphene and graphene nanoplatelets. Graphene from CVD is excluded as is reduced Graphene Oxide (rGO)].

The current challenge for the graphene industry is to incorporate graphene into real-world products and industrial processes. One of the major hurdles is that graphene is sold into a supply chain, with many players between the graphene producer and the final product. And each of these players has their own calculus of risk versus benefit. To be successful the graphene producer must demonstrate benefits to each player at every step along the supply chain, while meeting standards, helping to modify processes, overcoming regulatory hurdles and minimising supply chain disruptions. The successful companies will expand to cover several steps in the supply chain – for example graphene material, polymer compounds, plastic forming – and develop partnerships with other key supply chain players.

Over the next 3-5 years, one can imagine the commercial introduction of novel graphene enabled subsystems and systems. This category of products will include strong, light weight and highly functional nanocomposites for electric transportation vehicles, greatly improved energy systems (e.g., next generation batteries), high barrier packaging, smart textiles, and others. Solutions for highly regulated industries (e.g., medical, aerospace), some being demonstrated today, will start to exit their testing regimes and enter the marketplace.

Ultimately graphene will be part of building a sustainable future, playing a significant role in the replacement of costly, single function, or scarce materials with abundant, cheaper, and higher-performing ones. It will replace multiple and occasionally toxic additives with a single multi-functional material. It will reduce weight while increasing strength for a wide range of structural polymers and composites often leading to significant fuel savings in vehicles. It will extend the useful lifetime of paints, coatings and lubricants. And it will improve thermal management and energy storage in a wide range of applications, again improving efficiency while husbanding scarce resources.

NanoXplore is very well positioned to help customers participate in this emerging new world. With the combination of high quality graphene material, expertise in mixing graphene with a wide array of industrial materials, and a team of seasoned business leaders and material scientists with broad industrial experience, NanoXplore enables customers to achieve significant and affordable product improvements with very little added graphene.

Tags:  masterbatches  photovoltaics  polymers  supercapacitors 

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From the Lab to the Financial Markets: Applied Graphene Materials Leads the Way

Posted By Dexter Johnson, IEEE Spectrum, Wednesday, January 25, 2017

 

 

Back in 2010, Karl Coleman, a professor at Durham University in the UK, spun out a company at first known as Durham Graphene Science and then later floated on the stock market (AIM) as Applied Graphene Materials (AGM). 

The word quickly spread about AGM’s approach to producing graphene. The company’s manufacturing techniques did not require either a graphite source or a metal catalyst, with the latter leading to highly pure graphene platelets with little oxygen content.

From the outset, AGM has always been considered to have a flexible position in the graphene supply chain, with their product being adaptable to the needs of their clients. The company's graphene has been proposed for applications ranging from an indium-tin oxide (ITO) replacement in flexible displays to electrode material in batteries and supercapacitors. With its first production order and commercial application announced last October, we should begin to see the company’s flexibility demonstrate itself in the coming year. 

AGM is one of the few publicly traded graphene companies, which gives it a fairly unique position to observe the developing graphene markets. As one of The Graphene Council’s newest corporate members, we had the opportunity to ask some questions of AGM’s CEO, Jon Mabbitt, to get their view of graphene’s commercial development.

Q: The development of Applied Graphene Materials from university research to an AIM-traded business is a story that many lab research groups working with graphene and other 2D materials would like to duplicate.  What were a few of the most important factors that contributed to the success of your company bridging that gap between the lab and the fab?

A: Universities provide a fantastic environment in which to be creative, but often ideas do not progress beyond a single experiment or perhaps being the topic of a research paper. In our case the close connection between the Inorganic Chemistry department at Durham University and the Technology Transfer office facilitated the opportunity for the manufacturing processes to be financially supported. Without this early stage investment the ideas would probably have gone no further, but with seed capital and self-belief the people involved at this stage were able to deliver proof-of-concept. Another significant step was that the inventor recognised they were not necessarily best placed to lead the company going forward and was comfortable enough to pass on the responsibility to an experienced growth management team.

Q: Your corporate literature describes your production of graphene as a “bottom-up” process. Is this a chemical vapor deposition process or some kind of chemical exfoliation process? And do you see your process being adapted in some way that it could be used to produce monolayer graphene for electronic or optoelectronic applications in larger capacities than they are currently?

We describe our process as “bottom up” because we synthesize our graphene and do not exfoliate it from graphite. However, this is not a CVD process because we do not require a substrate on which to deposit the vapor. It is a chemical decomposition of alcohol, which is then reassembled to create the graphene nanoplatelets.

Q: It would seem that your current business model is that of a producer of graphene dispersions that supplies different product manufacturers to further enable their products? Do you see your business model evolving over time where you move further up the supply chain and eventually you would be manufacturing the products that are sold rather than the dispersions?

Our strategy is very simple: make graphene and format it. We only want to produce graphene and supply it in a format that can be easily handled by our customers and easily incorporated into their products. It is our customers who will create end products. Clearly by this approach working extremely closely with our customers is mutually beneficial to enable the optimum results.

Q: In your own business lines, what applications are showing the most potential for growth, i.e. coatings, composites, functional fluids, etc.? And why do you think this is the case: The underlying markets did not have any solution to the issues that the graphene-enabled products offered, or the graphene-enabled product outperformed what was currently in the market?

One of the Achilles heels of start-up companies is that they try to do too much. We have identified specific areas where we know our graphene material delivers particular benefits and so for now we remain focused on those areas: coatings (barrier performance), composites (mechanical performance) and functional fluids (friction modification). All sectors are looking for improvements, normally performance enhancement or cost reductions. The particular attributes graphene brings is that you get a lot of performance for very little quantity added. The ultra-high surface area to weight ratio combined with the chemical composition and bonding regime of graphene makes it super interesting. However, not all graphene is produced equally and the method of manufacture dictates the resultant properties of the material. Also whilst graphene has several attributes they cannot all be delivered concurrently in certain applications.

Q: In your dealings with customers, what is typically their biggest reservation in adopting your graphene dispersions and how do you typically overcome these doubts?

To gain customer interest you must provide credible data to support your assertions. Industrial companies will not spend time on technology concepts that are unproven. Once we have grabbed their attention then we need to support the customer really closely – things will go wrong before they go right and so a dogged mentality is essential. You also need to demonstrate that your business will continue to exist and be able to supply the products repeatedly and consistently in the long term.

Q: What do you think the overall market for graphene needs in order to see wider development of graphene-enabled products, i.e. more defined industry standards, just more time in the market, manufacturing costs to go lower? If all of these and more, which is the most acute?

I don’t believe there is or will be a distinct market for graphene, moreover graphene can be adopted largely as an additive to enhance a range of materials across several existing market sectors. I don’t subscribe to the idea that standardization will enable acceptance. Graphene is, and will remain for many years to come, a specialty chemical and exist in many different forms. There are some issues where a common approach would be beneficial for all, such as regulatory controls and H&S. Everyone involved in graphene needs more application successes and to achieve this there needs to be a bolder commitment from producers and advisors to go and make it happen.

Tags:  graphene platelets  ITO  publicly traded  stock market  supercapacitors 

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Additive Manufacturing & 3D Printing with Graphene

Posted By Terrance Barkan, Friday, January 20, 2017

 

3d printing, also known as additive manufacturing (AM), represents significant potential for the use of graphene material as an additive to the fast growing range of printable materials. This is increasingly true as there is a clear shift towards producing functional parts for industrial end use, including aerospace and automotive applications. 

Despite being a relatively low volume market at the moment, AM has several useful properties than make it an attractive market to a graphene producer as well as to end users. The AM market has a strong appetite to test new materials and to identify innovative applications not just in the AM processes, but in the characteristics of the materials that are used. Rapid process and testing times for new products mean that there is also a low barrier to entry compared to supplying nano-enhanced materials in other manufacturing industries. 

Because traditional AM materials are often quite expensive on their own, adding a relatively expensive material like graphene has less of an impact on the final costs than it might in some other large scale commercial applications. 

One of the advantages of AM is the ability to make one-off or specialty parts with no loss in production speed. Parts are also essentially the same price regardless of whether you print a few or a few thousand pieces. 

Although there are a large number of different AM technologies, there are really just three formats of material, (powders, liquids and filaments) and there are three main classes of material (metals, plastics and ceramics). Graphene has the potential to add desirable characteristics across many of these technologies, formats and material classes. 

One of the most important materials in use with AM today is polymers. There is significant scope for graphene to gain traction and market share here as an additive, primarily due to the ease of processing graphene into polymers. Common thermoplastics used in sintering and extrusion AM techniques include  ABS, PLA, nylons (6 and 12), TPU, PET and HIPS. Thermosets such as epoxy and acrylics are also popular in UV cured AM applications. Despite the relatively difficult processing challenges for metals and ceramics, there is potential for graphene to also add value across those technologies.

Graphene has the ability to provide improvements to conventional AM materials and in some case, these material improvements are unique to graphene. In particular, graphene can have an impact on;


• Much lower solids content 
• Shift material into a printability window 
• Improve HDT and shrinkage 
• Mechanical reinforcement where certain macro additives can’t be used
• Significant multi-functionality (5+ uplifts with one additive) 

 

Essentially graphene is adding benefits to or improving on the performance of a given consumable as well as mitigating or reducing the negatives. Multifunctionality is also important; gaining multiple beneficial properties without resorting to using several additives that might be incompatible with each other and doing so with a low addition rate lowers the risk of adding negative performance into a polymer, such as lower processability or brittleness. 

3D Printing and AM is just another of the many areas where graphene is proving worthy of a much closer look by materials scientists, product designers, engineers and production specialist across a broad range of industries. 

 

Want to learn more? 

 

Join an in-depth Webinar on Graphene and 3D Printing

Tags:  3D Printing  Additive Manufacturing 

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Thermionic Energy Converters on the Rise Thanks to Graphene

Posted By Dexter Johnson, IEEE Spectrum, Tuesday, January 10, 2017