Readers of the journal of the American Chemical Society have elected this graphene membrane with pores controlled at the atomic scale as the best molecule of 2018. This structure was presented in Science in a joint article by researchers from the ICN2, the CiQUS and the DIPC.
The porous graphene membrane synthesized by researchers from the Institut Català de Nanociència i Nanotecnologia (ICN2, a center of BIST and CSIC), the Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and The Donostia International Physics Center (DIPC) has been elected as the molecule of the year by the readers of C&EN magazine of the American Chemical Society with 58% of the votes among 8 international candidates.
Science magazine published this milestone in April in a work directed by the ICN2 Group Leader ICREA Prof. Aitor Mugarza and CiQUS IP Dr. Diego Peña. The article explained the potential of this precious material for applications in electronics, filters and sensors. The results of this study, whose first author is Dr. César Moreno from the ICN2, conducted with the molecule synthesized at CiQUS by Dr. Manuel Vilas Varela made possible the application for a patent.
The presence of pores in graphene pores whose size, shape and density can be tuned with atomic precision at the nanoscale can modify its basic structure and make it suitable as a selective filter for extremely small substances, from greenhouse gases to salt, to biomolecules. In addition, graphene becomes a semiconductor when the space between pores is reduced to a few atoms, opening the door for its use in electronic applications, where it could be used to replace the bulkier, more rigid silicon components used today.
Applied in conjunction, these two properties are predicted to allow the development of combined filter and sensor devices which will not only sort for specific molecules, but will alternatively block or monitor their passage though the nanopores using an electric field.
The resulting graphene exhibits electrical properties akin to those of silicon which can also act as a highly-selective molecular sieve. Applied in conjunction, these two properties are predicted to allow the development of combined filter and sensor devices which will not only sort for specific molecules, but will alternatively block or monitor their passage though the nanopores using an electric field.
Graphene holds the potential to deliver a new generation of ultrafast electronic devices. Current silicon technology can achieve clock rates – a measure of how fast devices can switch – of several hundred gigahertz (GHz). Graphene could achieve clock rates up to a thousand times faster, propelling electronics into the terahertz (THz) range. But, until now, graphene’s ability to convert oscillating electromagnetic signals into higher frequency modes has been just a theoretical prediction.
Now researchers from the Helmholtz Zentrum DresdenRossendorf (HZDR) and University of Duisburg-Essen (UDE), in collaboration with the director of the Max Planck Institute for Polymer Research (MPI-P) Mischa Bonn and other researchers, have shown that graphene can covert high frequency gigahertz signals into the terahertz range [Hafez et al., Nature (2018)].
“We have been able to provide the first direct proof of frequency multiplication from gigahertz to terahertz in a graphene monolayer and to generate electronic signals in the terahertz range with remarkable efficiency,” explain Michael Gensch of HZDR and Dmitry Turchinovich of UDE.
Using the novel superconducting accelerator TELBE terahertz radiation source at HZDR’s ELBE Center for High-Power Radiation Sources, the researchers bombarded chemical vapor deposition (CVD)-produced graphene with electromagnetic pulses in the frequency range 300–680 GHz. As previous theoretical calculations have predicted, the results show that graphene is able to convert these pulses into signals with three, five, or seven times the initial frequency, reaching the terahertz range.
“We were not only able to demonstrate a long-predicted effect in graphene experimentally for the first time, but also to understand it quantitatively at the same time,” points out Turchinovich.
By doping the graphene, the researchers created a high proportion of free electrons or a so-called Fermi liquid. When an external oscillating field excites these free electrons, rather like a normal liquid, they heat up and share their energy with surrounding electrons. The hot electrons form a vapor-like state, just like an evaporating liquid. When the hot Fermi vapor phase cools, it returns to its liquid form extremely quickly. The transition back and forth between these vapor and liquid phases in graphene induces a corresponding change in its conductivity. This very rapid oscillation in conductivity drives the frequency multiplication effect.
“In theory, [this] should allow clock rates up to a thousand times faster than today’s silicon-based electronics,” say Gensch and Turchinovich.
The conversion efficiency of graphene is at least 7–18 orders of magnitude more efficient than other electronic materials, the researchers point out. Since the effect has been demonstrated with mass-produced CVD graphene, they believe there are no real obstacles to overcome other than the engineering challenge of integrating graphene into circuits.
“Our discovery is groundbreaking,” says Bonn. “We have demonstrated that carbon-based electronics can operate extremely efficiently at ultrafast rates. Ultrafast hybrid components made of graphene and traditional semiconductors are also now conceivable.”
Nathalie Vermeulen, professor in the Brussels Photonics group (B-PHOT) at Vrije Universiteit Brussel (VUB) in Belgium, agrees that the work is a major breakthrough.
“The nonlinear-optical physics of graphene is an insufficiently understood field, with experimental results often differing from theoretical predictions,” she says. “These new insights, however, shine new light on the nonlinear-optical behavior of graphene in the terahertz regime.”
The researchers’ experimental findings are clearly supported by corresponding theory, Vermeulen adds, which is very convincing.
“It is not often that major advances in fundamental scientific understanding and practical applications go hand in hand, but I believe it is the case here,” she says. “The demonstration of such efficient high-harmonic terahertz generation at room temperature is very powerful and paves the way for concrete application possibilities.”
The advance could extend the functionality of graphene transistors into high-frequency optoelectronic applications and opens up the possibility of similar behavior in other two-dimensional Dirac materials. Marc Dignam of Queen’s University in Canada is also positive about the technological innovations that the demonstration of monolayer graphene’s nonlinear response to terahertz fields could open up.
“The experiments are performed at room temperature in air and, given the relatively short scattering time, it is evident that harmonic generation will occur for relatively moderate field amplitudes, even in samples that are not particularly pristine,” he points out. “This indicates that such harmonic generation could find its way into future devices, once higher-efficiency guiding structures, such as waveguides, are employed.”
He believes that the key to the success of the work is the low-noise, multi-cycle terahertz source (TELBE) used by the researchers. However, Dignam is less convinced by the team’s theoretical explanation of graphene’s nonlinear response. No doubt these exciting results will spur further microscopic theoretical investigations examining carrier dynamics in graphene in more detail.
Back a decade-and-a-half ago when the term “nanotechnology” was first garnering interest from the investment community, the UK-based specialty chemical company Thomas Swan had already launched into producing single-walled carbon nanotubes (SWCNTs) on a commercial scale. Having an established chemical company like Thomas Swan engaging commercially in nanomaterials provided a kind of imprimatur of respect that nanomaterials and nanotechnology were for real and not just some lab experiment.
Now Thomas Swan has added to their portfolio of nanomaterials by offering graphene and the two-dimensional version of the insulator boron nitride. This move, in its own way, provides another imprimatur that graphene and its commercial aspirations are for real and that the marketplace will need to take greater notice.
Thomas Swan has now joined The Graphene Council as a Corporate Member and with this new membership we took the opportunity to talk to Michael Edwards, the Business Director of Advanced materials at Thomas Swan, to get some further insight into why the company has entered the graphene business, how that business relates to their SWCNT business and how the company expects to see their graphene business as well as the market in general develop in the near future.
Q: Thomas Swan was one of the first established specialty chemical companies that got involved the manufacturing and development of nanomaterials, going back to your involvement in single-walled carbon nanotubes (SWCNTs) and now with graphene. What has been the reasoning that led Thomas Swan to enter these business lines so early?
A: It's always bee the vision of Harry Swan, to be honest with you. Harry is the owner of our business. He's the fourth generation of Swan. His initial involvement in the business was with carbon nanotubes, and subsequently, advanced materials.
We feel that it's an extension to the chemicals business. It provides leverage into different markets. Carbon nanotubes and subsequently graphene and now more recently, boron nitride, it is more the same; it's an extension of the business unit and a continuation of wanting to be at the forefront of technology.
Q: As mentioned, Thomas Swan has long been a producer of SWCNTs. What have you learned from your SWCNTs business that informs your graphene business? What are the differences between those two lines of business and what are their synergies?
A: What we learned from the CNT business was not to be too optimistic about forecasts. There's a lot of hype with new technology as the Gartner hype curve suggests. There are a lot of innovative start-up companies, some with a lot of early investment who are prepared to lead you down their vision of the end-goal. We've spent probably more than £10 million in investment in the two technologies over the last 10 years. We have capability for production, in volume that we can start immediately.
What we've learned is to be a little bit more patient with those new markets, understand the breadths and depths of them, and know that you have to talk to world leading manufacturers as well as innovators in order to get your overall perspective and product correct.
The synergies are in the characterization that you need to do. You need to have a different type of person scientifically between chemistry and materials. That was a good learning. In a sense carbon nanotubes and graphene are the same, but carbon nanotubes and graphene require a different approach to the chemicals business that we have. We have had to form a dedicated team but can still call on expertise in the areas of production, QA, Logistics, etc.
We need to have a different business development outlook instead of having established account management principles and long-term customer relationships, we need to use modern-day marketing methods such as lead generation, closing leads, social media tools and pipeline management, but all the while understanding a lot more about your end customers' application as business development has always been done
Graphene and carbon nanotubes are different in the respect that whilst they are both supply chain materials, graphene is far more of an additive than carbon nanotubes appears to be. In a sense, it's further down the food chain. You've got a diagram in the Graphene Council Bulk Graphene Report, which I use extensively, which shows the various different types of graphene.
Graphene tends to be a lot more difficult and it's more of an additive. You're getting far less benefit in graphene than you appear to be getting in carbon nanotubes unless you go to the right-hand side of that form and you reach what I call utopia, which is trying to meet that pristine, graphene defect-free perfect product.
Q: Could you give a bit more background on the type of graphene you're producing? The manufacturing process you employ, the markets you target for your graphene products?
A: We have an exclusive licensee for Trinity College Dublin's liquid-phase exfoliation, high-shear method. We manufacture using liquid phase exfoliation, but we have extended that to our own patents using homogenizers, which have a slightly different method of liquid-phase exfoliation.
We have a version of the technology in which we're up to tens-of-kilograms towards hundreds-of-kilograms production capacity with manufacturing capability today of few layer graphene, multilayer graphene. Using our scaled up technology adopting homogenization, we have graphene nanoplatelets with a capacity today up to about 20 tons. The beauty of this technology, and they're both patented and licensed to us, is that it's a linear scale up. We can quite readily move up to thousands of tons capability on the graphene nanoplatelets.
The areas that we're targeting are composites, lubricants, inks, coatings, and we're doing early work in battery technology. Also, since we have boron nitride, we are working hard in barrier coatings and thermal interface coatings as well. We offer both solutions in that area. With SWCNT’s we can address the semiconductor memory and battery chemistry areas also.
Q: Thomas Swan also manufactures other two-dimensional materials, namely molybdenum disulfide (a semiconductor) and boron nitride (an insulator), correct? Are you making heterogeneous materials with these other 2D materials?
A: We haven't really done a lot of work with molybdenum disulfide. Part of that is because—this goes back to that chain of command of graphene products—that tends to be a semiconductor. You tend to need to have your business development team focused on a different market.
The boron nitride that we're working on, as I said, fits quite neatly alongside graphene. Often we can sell our powders dispersion or masterbatches as boron nitride or graphene. It gives us the flexibility to talk to customers. That's basically the way that we're going to market.
Q: How far do you see your company moving up the value chain of 2D materials? Will the company consider making devices with the materials you are producing? Where would the company draw the line in moving up the value chain?
A: Well, the company itself is mainly a performance chemicals company, toll- manufacturing and now advanced materials company. The extent to which I think we’ll move up the value chain probably will stop at masterbatches, inks and maybe coatings,. Based on the fact that we've got a global reach with major global corporates, our preferred approach is to work with these guys’ R&D teams, and we will get put right back in our place if we try to overextend.
We sit in the value chain, we provide good value, we have a very strong manufacturing ethos with capability for operations and distribution outlets around the globe already in place. I believe we know where we fit in our value chain and it will extend no further than what I've mentioned.
Having said that, and going back to the question about what technology we have, we have just patented a technology, which allows us to do a bottom-up process. We’ll be able to talk more about that in the next month-or-so. However, we have filed the patent and it's a process that allows us to use our current processing technology. Furthermore, it allows us to produce some forms of functionalized graphene. There will be news on this over the next couple of months in terms of each detail and our marketing strategy.
I believe, as we move up the application chain, we add more value to our customers potential. It will certainly add to our base product road map, but we always try to add more to our service to our customers by offering them an option, utilizing the strengths of our R&D team here. Potentially it's a good solution because we've already trialed this with our production technique. It's another string to our bow.
Q: What do you see for the future of graphene’s commercial interests, i.e. a reduction of the number of applications or an increase, market consolidation for both producers and buyers, etc.?
A: I think it's a rationalisation more than anything. I think there will be a commodity graphene area, which is looking at areas such astyres and carbon black in that space as well as asphalt/concrete where you'll really need to get high volume producers who are capable of getting the price down significantly.
There will also be that niche middle ground where we will palce ourselves, adding value to a customer’s product, trying to get 10% to 20% improvement on one or two parameters of that product to give them access to the market, and therefore you'll have be influential intheir overall value proposition.
It's that high-end electronics defect-limited, single-sheet graphene which is going into the electronics field. To some extent, that's also where our single-wall carbon nanotubes may end up is in that electronics field where you're adding some value. Maybe even in batteries. That will get a little bit smarter. I believe therefore there are three distinct categories and the definition of those various graphene subsets probably help in that definition.
We won't be a huge volume manufacturer, typically hundreds to thousands tonnes annually, but our technology might well lend itself to helping our customers in their specific niches.
You can already see some of our competition linking themselves to mines, and talking about really high volume. I think there’s room for a few of these companies, but we probably won't play in that area.
Q: At this point, do you believe that a lack of standards poses a real limiting factor the commercial expansion of graphene?
A: I think the recent definition is helping clarify the situation. I think a lack of standards is always a problem, and it prevents major players doing anything more than dipping their toe in the water. I absolutely agree that standards will help drive the market. I believe it will help define both product and applications far more clearly.
Researchers at the University of Virginia (UVA) have devised a process for converting retired Li-ion battery anodes to graphene and graphene oxide (GO). A paper on the work is published in the ACS journal Nano Letters.
Schematic illustration of the proposed smart fabrication of graphene and graphene oxide from end-of-life batteries. Zhang et al.
… accompanying the booming expansion of the Li-ion battery market, a tremendous amount of batteries retire every year and most of them are disposed of in landfills, which not only causes severe waste of precious sources but also induces hazardous soil contamination due to the plastic components and toxic electrolytes. So far, only 1% of end-of-life Li-ion batteries have been recycled. Apparently, it is an urgent necessity to develop effective battery recycling techniques.
… A rational strategy to simultaneously solve the environmental issues from waste batteries and graphite mining is to fabricate graphene directly from end-of-life battery anodes.
… Here, graphite powders from end-of-life Li-ion battery anodes were used to fabricate graphene.
—Zhang et al.
Graphite powders collected from end-of-life Li-ion batteries exhibited irregular expansion because of the lithium-ion intercalation and deintercalation in the anode graphite during battery charge/discharge.
Such lattice expansion of graphite can be considered as a prefabrication of graphene because it weakened the van der Waals bonds and facilitated the exfoliation.
—Zhang et al.
This “prefabrication” process facilitates both chemical and physical exfoliations of the graphite. Comparing with the graphene oxide derived from pristine, untreated graphite, the graphene oxide from anode graphite exhibited excellent homogeneity and electrochemical properties.
The lithiation aided pre-expansion enabled 4 times enhancement of graphene productivity by shear mixing, the researchers found.
The graphene fabrication was seamlessly inserted into the currently used battery recycling streamline in which acid treatment was found to further swell the graphite lattice, pushing up the graphene productivity to 83.7% (10 times higher than that of pristine graphite powders).
Applied Graphene Materials, originally spun out of Durham University and now based in Redcar, is creating a new range of graphene-enhanced anti-corrosion aerosols for James Briggs.
AGM say the completion of its first production batch is a "significant milestone" and they now plan to work towards a full product launch.
Based at the Wilton Centre, near Redcar, AGM makes powdered graphene, with the substance hailed by some experts as being capable of conducting electricity a million times better than copper, despite being as thin as human hair.
The business has developed a form of graphene it says can deliver a six-fold improvement in barrier and anti-corrosion properties, with James Briggs expected to use the product in primers to offer greater protection from weathering.
Bosses claim testing had demonstrated "repeated improvements in anti-corrosion performance".
Bryan Dobson, chairman of Applied Graphene Materials, said: "The Board continues to focus on the commercialisation of its products and proprietary technologies via its numerous active engagements and has made good progress in recent months.
"I am pleased to report that we have recently achieved a key milestone, having fulfilled the scale-up production purchase order from James Briggs Ltd in preparation for full product launch.
"JBL has successfully completed its first production batch which is a significant milestone for commercial realisation. Extensive testing has demonstrated repeated and outstanding improvements in anti-corrosion performance for JBL’s automotive aerosol primer. JBL plans to launch their new range of graphene enhanced anti-corrosion aerosols under their Hycote brand."
Mr Dobson als said the firm was pleased to participate in the opening of the UK’s Graphene Engineering and Innovation Centre (GEIC) in Manchester last week.
"Meeting with multiple participants, the opportunities for graphene technology remain buoyant," he said.
"Finding practical application solutions for the challenges surrounding the exploitation of graphene nanoplatelet technology is the key focus of AGM’s strategy for commercial progress.
"We look forward to working closely with GEIC in the months ahead in the further development of world-class application solutions."
James Briggs was founded almost two centuries ago and they have the capacity to distribute up to 150 million aerosols.
San Diego based graphene and 2D materials producer Grolltex has completed characterization and is releasing for commercial sale a configuration of large area, single layer graphene that exhibits dramatically improved ‘electron mobility’, which translates to better graphene performance. This ‘heterostructure’ contains a layer or layers of hexagonal Boron Nitride (or ‘hBN’) underneath graphene, enabling enhanced graphene capabilities.
Grolltex has begun commercial pre-sales to customers of this ‘Enhanced Performance Graphene’ product, which can significantly improve device performance for sensing, transistors, connectivity and other key aspects of nano-devices. This type of material performance improvement is often a stepping stone for new applications enabling large market growth toward faster, smaller, cheaper and more sensitive silicon-based devices.
“The data back from our large European device partner showed carrier mobility performance improvements starting at 30%, and our internal work shows us that with some configuration adjustments, we can even build on this toward electron mobility improvements in exponential regimes”, said Jeff Draa, Grolltex CEO and co-founder. “We believe this is going to be incredibly important to many of our customers that build things on silicon”.
The first reason for the improvement of graphene electron mobility performance, when layered on top of hBN on a wafer, is that the underlying layer of hBN, between the wafer and the graphene, planarizes the surface of the silicon wafer and allows graphene to sit on a surface (hBN) far more conducive to graphene electron flow.
Another reason has to do with the electron interference of the oxide coming out of the underlying Si/SiO2 wafer, if graphene sits directly on top of it. With the hBN layer between the graphene and the wafer, the negative effect of the oxide from the wafer on graphene electron performance is greatly reduced, allowing a much freer flow of graphene electrons. Additional advantages are lower processing temperatures and a much stronger adhesion of the graphene layer to the underlying substrate, with hBN present.
“So, when graphene sits on hBN, it performs much closer to the theoretical ‘electron superhighway’ that graphene users expect”, according to Draa. “We have characterized and are selling this heterostructure to our pre-qualified customers in up to 8” (200mm) diameter configurations and can layer hBN and graphene in any combination”.
“Device designers, especially advanced sensor makers, are really keyed in to electron mobility. There are many variables that affect this and he who can square those away and show dramatic improvements in mobility can help add real, unique and substantial value to device performance”, said Draa. “Next on our characterization list is MoS2, which is an important ‘band-gap’ material that has been missing in 2D offerings.”
Grolltex, short for ‘graphene-rolling-technologies’, uses patented research and techniques initially developed at the University of California, San Diego, to produce high quality, single layer graphene, hexagonal Boron Nitride and other 2D materials and products. The company is a practitioner of, and specializes in, exclusively sustainable graphene production methods and is committed to advancing the field of graphene to improve the future of leading edge materials science and product design through the optimization of single atom thick materials.
Grolltex, Inc., is a nanotechnology materials, products and equipment company focusing on the optimization and advancement of the key monolayer material ‘graphene’ and related 2D materials. The company holds a number of strategic patents and technological advantages in areas relating to the manufacture of high quality, monolayer ‘CVD’ graphene and hexagonal Boron Nitride as well as on several advanced products made of graphene and 2D materials, such as hyper efficient solar cells, next generation sensors, advanced fuel cells and futuristic super-thin and flexible displays for use in wearables, smart phones and other electronics.
For complete information, please visit: https://grolltex.com/
The two teams based at The University of Manchester are seeking breakthroughs by using graphene in the treatment of brain cancer and to radically improve battery performance.
The Eli and Britt Harari Graphene Enterprise Award, in association with Nobel Laureate Sir Andre Geim, is awarded each year to help the implementation of commercially-viable business proposals from students, post-doctoral researchers and recent graduates of The University of Manchester based on developing the commercial prospects of graphene and related 2D materials.
The first prize of £50,000 was awarded to Honeycomb Biotechnology and its founders; Christopher Bullock, a Biomedical Engineer in the School of Health Sciences who is due to complete his PhD on developing novel graphene biomaterials this autumn, and Richard Fu, a NIHR Academic Clinical Fellow and Specialty Registrar in Neurosurgery based at the Manchester Centre for Clinical Neurosciences.
The team are seeking to develop a surgically implanted device using graphene electrodes to deliver targeted electrotherapy for the treatment of Glioblastoma Multiforme- a form of brain cancer. They hope that this technology can work in conjunction with other treatment modalities to one day turn fatal adult brain cancer into a manageable chronic condition.
Richard Fu said: “Glioblastoma Multiforme (GBM) remains a tragic and deadly disease. This award provides us with the opportunity and funding to further develop what is currently an exploratory treatment idea that could one day make a meaningful difference to the lives of patients”.
Christopher Bullock added: “We are very grateful to Eli and Britt Harari for their generosity and for the support of the University, which has enabled us to try and turn our ideas into something that makes a real difference”.
"Our commitment to the support of student entrepreneurship across the University has never been stronger and is a vital part of our approach to the commercialisation of research. The support provided by Eli Harari over the last four years has enabled new and exciting new ventures to be developed. It gives our winners the early-stage funding that is so vital to creating a significant business, while also contributing to health and social benefit. With support from our world-leading graphene research facilities I am sure that they are on the path to success!"
Professor Luke Georghiou, Deputy President and Deputy Vice-Chancellor
The runner-up, receiving £20,000, was Advanced Graphene Structures (AGS), founded by Richard Fields, Alex Bento and Edurne Redondo. Richard has a PhD in Materials Science and Edurne has a PhD in Chemistry, they are both currently research associates at the University; Alex is currently working as a freelance aerospace engineer.
Richard Fields said: “Many industries are interested in benefiting from the properties of graphene, but they are hindered by a lack of new processing tools and techniques, ones which could more effectively capture these beneficial properties. We intend to develop new tools and techniques which can constructively implement graphene (alongside other 2D/nanomaterials) into advanced energy storage devices and composite materials”.
The technology aims to radically improve the performance of composite materials and batteries, this will be achieved by providing control over the structure and orientation of 2D/nanomaterials used within them. An added benefit of the solution is rapid deployment; the team have identified a real technological opportunity, which can be readily added to existing manufacturing processes.
Graphene is the world’s first two-dimensional material, one million times thinner than a human hair, flexible, transparent and more conductive that copper.
No other material has the same breadth of superlatives that graphene boasts, making it an ideal material for countless applications.
The quality of the business proposals presented in this year’s finals was exceptionally high and Professor Luke Georghiou, Deputy President and Deputy Vice-Chancellor of The University of Manchester and one of the judges for this year’s competition said: “Our commitment to the support of student entrepreneurship across the University has never been stronger and is a vital part of our approach to the commercialisation of research. The support provided by Eli Harari over the last four years has enabled new and exciting new ventures to be developed. It gives our winners the early-stage funding that is so vital to creating a significant business, while also contributing to health and social benefit. With support from our world-leading graphene research facilities I am sure that they are on the path to success!”
The award is co-funded by the North American Foundation for The University of Manchester through the support of one of the University’s former physics students Dr Eli Harari (founder of global flash-memory giant, SanDisk) and his wife Britt. It recognises the role that high-level, flexible early-stage financial support can play in the successful development of a business targeting the full commercialisation of a product or technology related to research in graphene and 2D materials.
Advanced materials is one of The University of Manchester’s research beacons - examples of pioneering discoveries, interdisciplinary collaboration and cross-sector partnerships that are tackling some of the biggest questions facing the planet. #ResearchBeacons
Haydale, the global advanced materials group, has announced that it has completed the installation and commissioning of a two-roll lab mill at its site in Loughborough, UK.
This new investment will allow Haydale to compound nanomaterials into a range of elastomers which will support customers interested in using nanomaterials in their elastomeric products for a range of property improvements, such as thermal conductivity, electrical conductivity and increased mechanical performance.
The new elastomer mixing capability sits alongside the current elastomer moulding and testing facilities that are already on site at Haydale in Loughborough, UK, thereby bringing in-house the facility for Haydale to serve customer requirements for nanomaterial enhanced elastomer development.
Areas Haydale is currently working on with elastomers are:
Auto, rail and marine for antivibration mounts.
Seals and gaskets.
Keith Broadbent, Haydale Managing Director Composites, said: “We are really pleased to be able to offer this additional capability from our Loughborough site and look forward to working more closely with our existing, and new, elastomer customers.”
Ray Gibbs, Haydale CEO, said: “This market-led improvement to our facility shows how Haydale is responding to the needs of its customers.”
Advanced materials company, First Graphene Limited (“FGR” or “the Company”) (ASX: FGR) is pleased to announce the launch of its 50%-owned associate company, 2D Fluidics Pty Ltd, in collaboration with Flinders University’s newly named Flinders Institute for NanoScale Science and Technology.
The initial objective of 2D Fluidics will be the commercialisation of the Vortex Fluidic Device (VFD), invented by the Flinders Institute for NanoScale Science and Technology’s Professor Colin Raston. The VFD enables new approaches to producing a wide range of materials such as graphene and sliced carbon nanotubes, with the bonus of not needing to use harsh or toxic chemicals in the manufacturing process (which is required for conventional graphene and shortened carbon nanotube production).
This clean processing breakthrough will also greatly reduce the cost and improve the efficiency of manufacturing these new high quality super-strength carbon materials. The key intellectual property used by 2D Fluidics comprises two patents around the production of carbon nanomaterials, assigned by Flinders University.
2D Fluidics will use the VFD to prepare these materials for commercial sales, which will be used in the plastics industry for applications requiring new composite materials, and by the electronics industry for circuits, supercapacitors and batteries, and for research laboratories around the world.
2D Fluidics will also manufacture the VFD, which is expected to become an in-demand state-of-the-art research and teaching tool for thousands of universities worldwide, and should be a strong revenue source for the new company.
Managing Director, Craig McGuckin said “First Graphene is very pleased to be partnering Professor Raston and his team in 2D Fluidics, which promises to open an exciting growth path in the world of advanced materials production. Access to this remarkably versatile invention will complement FGRs position as the leading graphene company at the forefront of the graphene revolution.”
Professor Colin Raston AO FAA, Professor of Clean Technology, Flinders Institute for NanoScale Science and Technology, Flinders University said “The VFD is a game changer for many applications across the sciences, engineering and medicine, and the commercialisation of the device will have a big impact in the research and teaching arena,” Nano-carbon materials can replace metals in many products, as a new paradigm in manufacturing, and the commercial availability of such materials by 2D Fluidics will make a big impact. It also has exciting possibilities in industry for low cost production where the processing is under continuous flow, which addresses scaling up - often a bottleneck issue in translating processes into industry.”
Photons are faster than electrons. This has lead scientists to see if they can harness light (photons) to operate an integrated circuit. While this should result in faster circuits, there’s a hitch: wavelengths of light are much larger than the dimensions of today’s computer chips. The problem is that you simply can’t compress the wavelengths to the point where they work in these smaller chip-scale dimensions.
Scientists have been leveraging a new tool lately to shrink the wavelengths of light to fit into smaller dimensions: plasmonics. Plasmonics exploits the waves of electrons—known as plasmons—that are formed when photons strike a metallic structure. Graphene has played a large role in this emerging field because it has the properties of a metal—it’s a pure conductor of electrons.
The Institute of Photonic Sciences (ICFO) in Barcelona, which has been a leader in this field for years, is now reporting they have taken the use of graphene for shrinking the wavelengths of light to a new level. In research described in the journal Science, ICFO researchers have managed to confine light down to a space one atom thick in dimension. This is certainly the smallest confinement ever achieved and may represent the ultimate level for confining light.
The way the researchers achieved this ultimate confinement was to use graphene along with one of its two-dimensional (2D) cousins: hexagonal boron nitride, which is aninsulator.
By using these 2D cousins together, the researchers created what’s known as van der Waals heterostructures in which monolayers of different 2D materials are by stacked on top of each other and held together by van der Waal forces to create materials with tailored electronic properties—like different band gaps for stopping and starting the flow of electrons. In this case, the layers included hexagonal boron nitride layered on top of the graphene and then involved adding an array of metallic rods on top of that. This structure had the graphene sandwiched between an insulator and a conductor. The graphene in this role served to guide the plasmons that formed when light struck the outer metallic rods.
In the experiment, the ICFO researchers sent infrared light through devices made from the van der Waal heterostructures to see how the plasmons propagated in between the outer metallic rods and the graphene.
To get down to the dimensions of one atom for confining the light, the researchers knew that they had to reduce the gap between the metal and the graphene. But the trick was to see if it was possible to reduce that gap without it leading to additional energy losses.
To their surprise, the ICFO researchers observed that even when a monolayer of hexagonal boron nitride was used as a spacer, the plasmons were still excited by the light, and could propagate freely while being confined to a channel of just on atom thick. They managed to switch this plasmon propagation on and off, simply by applying an electrical voltage, demonstrating the control of light guided in channels smaller than one nanometer of height.
The researchers believe that these results could to lead a new generation of optoelectronic devices that are just one nanometer thick. Down the road, this could lead to new devices such as ultra-small optical switches, detectors and sensors.
The Mobile World Congress (MWC) held annually in Barcelona, Spain is one of the largest technology conferences in the world. For the last three years, the MWC has been hosting the Graphene Pavilion that showcases the research institutes and technologies that they have developed under the EU’s Graphene Flagship.
The Graphene Council visited the Graphene Pavilion last month in Barcelona and we came back with some videos. One of the anchor institutions at the Pavilion is The Institute of Photonics (ICFO) located just outside of Barcelona. The Graphene Council has been speaking to Frank Koppens at ICFO since 2015 about how graphene was impacting photonics and optoelectronics.
In our latest visit with them at MWC this year, we got an update on some of the ways they are applying their technologies to various technologies.
In the one shown in the video below, the researchers have developed ultraviolet (UV) sensors for protecting the wearers from overexposure to the sun.
What the ICFO discovered six years ago was that while graphene generates an electron-hole pair for every single photon the material absorbs generates, it doesn’t really absorb that much light. To overcome this limitation of graphene, they combined it with quantum dots with the hybrid material being capable of absorbing 25 percent of the light falling on it. When you combine this new absorption capability with graphene’s ability to make every photon into an electron-hole pair, the potential for generating current became significant.
The ICFO has been proposing applications like this for this underlying technology for years, and producing working prototypes. At the MWC in 2016, the ICFO was exhibiting a heart rate monitor. In that device, when a finger is placed on the photodetector, the digit acts as an optical modulator, changing the amount of light hitting the photodetector as your heart beats and sends blood through your fingertip. This change in signal is what generates a pulse rate on the screen of the mobile device.
This same basic technology is at the heart of another technology ICFO was exhibiting this year (see video below) in which the graphene-based photodector can determine what kind of milk you are about to drink. This could conceivably be used by someone who has a lactose intolerance that could threaten their lives and by using the detector could determine if it was cow’s milk or soy milk, for instance.
While ICFO goes so far as to discuss prices for the devices, it’s not clear that ICFO is really committed to any of these technologies for its wide-spectrum CMOS graphene image sensor, or not. In the case of the heart monitor, the researchers claimed at the time it was really just intended to demonstrate the capabilities of the technology.
The long-range aim of the technology is to improve the design of these graphene-based image sensors to operate at a higher resolution and in a broader wavelength range. Once the camera is improved, the ICFO expects that will be used inside a smartphone or smart watch. In the meantime, these wearable technologies offer intriguing possibilities and maybe even a real commercial avenue for the technology.
Advanced materials company, First Graphene Limited (ASX: FGR) is working with the University of Adelaide (UoA) on graphene for industrial building products.
Graphene in Concrete
Experiments have been conducted on the use of graphene oxide (GO) being added to concrete to improve both compressive and tensile strength. However the hydrophilic and high resistivity nature of GO limits its applications in things such as ‘smart’ cement.
Due to the high aspect ratio of nano-reinforcements such as graphene and carbon nanotubes, they have the ability to arrest crack propagation in concrete (by controlling the nano-sized cracks before they form micro-sized cracks) and hence greatly improve peak toughness, making them more effective than even conventional steel bar or fibre reinforcements.
Premium Concrete Products – Smart Cement
Ultra-High Performance Concrete (UHPC) operates at such a high-performance level that it competes with steel rather than regular concrete grades. Advantages include lower lead times compared to steel. UHPC can cost in excess of $500/tonne, with enhancements such as micro-reinforcements further increasing the price.
Due to the immense importance of compression strength and other factors such as blast, ballistic and earthquake resistance, additive premiums can be significant. UHPC is over an order of magnitude more expensive than regular concrete, but in an environment where material usage and weight are such essential considerations, it can actually be cheaper to use the more expensive grades in the long run, especially factoring in the reduced maintenance costs incurred by UHPC.
The UoA is testing FGR graphene, with the aim of making “smart cement” with conductive graphene flakes which may;
i. address the concerns of cracking and corrosion, and
ii. provide conductivity for better monitoring the health of concrete structures.
The first test results indicate the addition of just 0.03% standard graphene by weight is the optimal quantity of graphene from the test conducted to date, showing a 22 - 23 % increase in compressive and tensile strength, respectively. The addition of more standard graphene does not increase or decrease the strength of the concrete material when compared to the control in this test work.
Promising Results with Favourable Economics
This initial work has yielded very promising results with very small amounts of FGR graphene required to greatly increase the strength of the materials. Determining the optimum mixing methods and concentration to develop a consistent material will be the key to further developing this project.
The focus of the next stage of the work will be trialling other concentrations of graphene in concrete, specifically loading at 0.01% and 0.1% graphene, and optimisation of the mixing procedures. New methods of incorporating graphene into the concrete mixture will also be trialled.
The graphene provided by FGR will have a range of aspect ratios (smaller sheet sizes) and will be tested over the full range of concentrations. It is anticipated this material will better disperse within the concrete mixture and therefore provide further mechanical strength improvements.
The concrete admixtures market is estimated to be worth US$18.10bn by 2020. The drivers identified for the concrete admixtures demand are growing infrastructure requirements in developing economies, improving economics of construction, and shifting preferences of population towards urbanisation.
A group of researchers from Denmark, UK and Spain within the Graphene Flagship project, explains in a recent review paper why the graphene industry needs better and faster electrical characterisation methods. The Graphene Flagship is a large European project, with more than hundred research groups collaborating on development of novel graphene technologies and applications.
Just 5 years after the first announcement that graphene could be isolated at all, Rod Ruoff (2009) and Samsung (2010) showed that graphene can be synthesized in a deceptively simple way; by decomposing hydrocarbons at high temperature, leaving single layer graphene sheets to crystallise on a copper surface.
Today, just 7 years later, graphene sheets are produced and used in large quantities – or areas – for instance for cell phone touch screens, according to Chinese researchers.
While large-area fabrication is taking off fast, the methods for quality control are lagging behind – and this is particularly true with respect to the electronic properties that are central to many applications.
Electrical measurements are most often done by turning the graphene film into a number of electrical devices, where field effect measurements give the “key performance indicators” of conductivity, carrier density and mobility. Depending on the number of devices, and the time spent on measuring, such tests can also give an idea about the variability. The two main drawbacks are ; (1) the process is fundamentally destructive – the graphene is irreversible damaged in the process, and (2) the throughput is many orders of magnitude smaller than the CVD-based fabrication of the graphene in the first place creating a bottleneck.
Researchers at the Technical University of Denmark and at the National Physics Laboratory in UK have over the past several years developed a number of fast, large-scale, non-destructive characterisation techniques of electronic properties that they believe have the potential to become game changing technologies.
A recent review focuses on one of these: terahertz time-domain spectroscopy (THz-TDS).
THz-TDS shoots terahertz pulses through the graphene and measures how much the film absorbs. The absorption spectrum up to 2 THz depends distinctly on the conductivity as well as on the scattering time – a measure of the average time the carrier spend between collision with obstacles.
Knowing these two, the carrier density and mobility can be computed. The technique has been meticulously verified against electrical measurements and is now being proposed as a metrology standard, in collaboration with the Spanish company DasNano, who are the first to manufacture terahertz-based conductivity mapping equipment for graphene.
Peter Bøggild, professor at DTU puts it like this: “Trivially, there can be no industry without quality, and there can be no quality without quality control. Non-contact mapping is fast and non-destructive, so anyone interested in consistency, reproducibility and reliability of graphene films, should pay attention.”
Quietly, behind the scenes and under the cover of NDA’s and confidentiality agreements, graphene is making significant commercial advances.
Speaking with graphene producers, the story this year has been consistent; they are selling material but they are unable to publicly disclose the end-users or the application areas due to the commercially sensitive information and the desire for their customers to maintain a first mover advantage.
So how do you promote a material for which there are limited examples and the customers will not agree to be named or to allow the products to be disclosed?
Based on conversations with producers, we know enough to be able to say with confidence that the majority of the material being sold is “bulk” graphene; this refers to graphene nano particles (GNPs), graphene oxide (GO) and reduced graphene oxide (rGO), graphene powders, graphene in suspension and graphene sold in master batches.
We know that the lion’s share of the market is for nanocomposite materials based on surveys of more than 400 graphene application developers, producers and end-users. In fact it is more than 50% of the total current market.
These applications include the use of graphene in plastics, polymers, 3D printing, rubber, with carbon fibers and CNTs, as well as in concrete and steel applications.
We also know that virtually every major bona fide graphene producer has announced or has indicated a significant production capacity increase for 2017, 2018 or 2019 at the latest, based on the market pull through for the material.
And this progress is not limited just to bulk graphene but also to single layer CVD graphene as well with the recent ability to produce wafer sized products at a dramatically reduced price compared to just 1 year prior.
How do we take the next steps towards greater commercialization?
The Graphene Council is working with vertical industries, like the composites sector, to help educate and inform those companies that would be the largest buyers and users of this material about how graphene enhances or enables better solutions (strength, flexibility, conductivity, wear resistance, thermal properties, etc.).
We see our mission as being a catalyst to help raise the level of awareness in the end-user community about the possibilities that graphene offers and to dispel some of the myths that have been created from the over-hyped expectations of the past few years.
In a recent review of more than 60 graphene products, more than 45 different material characteristics were listed by at least one of the materials studied. Yet not one single characteristic (not the carbon content, not the carbon layer count, etc.) was common across every product. In fact, there was not a single material characteristic as listed on the specifications sheets that was shared by more than 75% of the products listed.
It is impossible for a buyer of graphene to be able to compare products based on the spec sheets alone and it is prohibitively expensive to expect the consumer to test each supplier’s material to just know what they are getting.
As a result, we see a tremendous need to help buyers identify trusted suppliers of quality materials.
As we enter 2018, The Graphene Council will focus on accelerating the commercial adoption of graphene and representing the interests of our members by;
a.) educating targeted industries like composites, coatings, energy storage, etc.,
inov-8 is launching a revolutionary world-first in the sports footwear market following a unique collaboration with scientific experts. The British brand has teamed up with The University of Manchester to become the first-ever company to incorporate graphene into running and fitness shoes.
Laboratory tests have shown that the rubber outsoles of these shoes, new to market in 2018, are stronger, more stretchy and more resistant to wear.
Michael Price, inov-8 product and marketing director, said: “Off-road runners and fitness athletes live at the sporting extreme and need the stickiest outsole grip possible to optimize their performance, be that when running on wet trails or working out in sweaty gyms. For too long, they have had to compromise this need for grip with the knowledge that such rubber wears down quickly."
“Now, utilising the groundbreaking properties of graphene, there is no compromise. The new rubber we have developed with the National Graphene Institute at The University of Manchester allows us to smash the limits of grip."
“Our lightweight G-Series shoes deliver a combination of traction, stretch and durability never seen before in sports footwear. 2018 will be the year of the world’s toughest grip.”
Commenting on the collaboration and the patent-pending technology, inov-8 CEO Ian Bailey said: “Product innovation is the number-one priority for our brand. It’s the only way we can compete against the major sports brands. The pioneering collaboration between inov-8 and the The University of Manchester puts us – and Britain – at the forefront of a graphene sports footwear revolution."
“And this is just the start, as the potential of graphene really is limitless. We are so excited to see where this journey will take us.”
The scientists who first isolated graphene were awarded the Nobel Prize for physics in 2010. Building on their revolutionary work, the team at The University of Manchester has pioneered projects into graphene-enhanced sports cars, medical devices and aeroplanes. Now the University can add sports footwear to its list of world-firsts.
Dr Aravind Vijayaraghavan, Reader in Nanomaterials at the University of Manchester, said: “Despite being the thinnest material in the world, graphene is also the strongest, and is 200 times stronger than steel. It’s also extraordinarily flexible, and can be bent, twisted, folded and stretched without incurring any damage.
“When added to the rubber used in inov-8’s G-Series shoes, graphene imparts all its properties, including its strength. Our unique formulation makes these outsoles 50% stronger, 50% more stretchy and 50% more resistant to wear than the corresponding industry standard rubber without graphene.”
“The graphene-enhanced rubber can flex and grip to all surfaces more effectively, without wearing down quickly, providing reliably strong, long-lasting grip."
“This is a revolutionary consumer product that will have a huge impact on the sports footwear market.”
Last week, the city of Luxembourg played host to The Economist’s “The Future of Materials Summit”. The agenda was heavily influenced by the Russian-based single-wall carbon nanotube (SWNTs) producer, OCSiAl, which not only sponsored the event but also plans to open a SWNT production facility in Luxembourg.
With the Luxembourg prime minister, Xavier Bettel, providing a keynote in which he expressed his hope that Luxembourg could bring back its manufacturing glory days when it was one of Europe’s largest steel producers, the hope seemed to be squarely placed on the potential of SWNTs to be the engine for Luxembourg’s economic transformation back to manufacturing.
In what may have been the most interesting set of ironies of the conference, one of the world’s largest steel producers today—Tata Steel—provided testimony that the future of steel manufacturing is not turning towards the expensive and finicky SWNTs, but instead is developing a cheaply produced form of graphene that promises to drastically improve corrosion resistance in steel.
Sanjay Chandra, Chief of Research and Development and Scientific Services at Tata Steel, provided one of the only examples at the conference on how novel materials move from discovery to high volume production. And in this case, the discovery process was quite unexpected.
“We were looking at coatings that would improve the corrosion resistance of steel,” said Chandra in an interview immediately after his presentation. “There is already zinc, of course, but there are a lot of environmental issues with the zinc as well as the costs associated with it. So we came across this bio product from a tree. It is the secretion that an insect makes as it sits on the seeds of the tree. You could call it a bio extract, and we were able to convert this material into graphene.”
The graphene takes the form of graphene oxide in which the carbon-to-oxygen ratio is about 30% to 40%, and, according to Chandra, it provides very good corrosion resistance.
“Its conductivity is good enough for some of the sensors that are used in the pharmaceutical industry and the main feature of our product is that can we can produce it at a very low cost because it can be produced in very large volumes and very rapidly,” said Chandra.
Currently, the process that Chandra and his colleagues at Tata Steel are employing with the graphene oxide is a manual process of dipping the steel in a liquid created by this powder. While this is good enough for testing, Chandra concedes that in order to replace zinc in steel production they will need to develop a more refined process.
“We need a process that can fit into a steel plant that is producing these galvanized sheets of steel at very high speeds and all in one sequence,” he added. “So for us to be able to do that that's a bit of a challenge.”
Part of the challenge is that it is very difficult to get someone to retrofit a steel assembly line because of production disruptions. However, with the graphene material offering at least a doubling of corrosion resistance over zinc and offering biocompatibility there is certainly reason to look into overcoming these production obstacles.
Most of the research and development that has been done so far with the material and processes has been performed in house at Tata Steel. Chandra explained that this was not because of any reticence to work with outside research groups—which Tata Steel does quite regularly—but instead they have not been able to identify the appropriate group that could help them scale up the production for steel applications. Another problem is just the culture of the steel industry, which has proven to be not very good at engineering and design, which is where the current problems resides.
To address these issues Tata Steel has taken the forward thinking measure of funding a new research group at the Indian Institute of Technology in Madras to look at among other things this material and how to potentially scale up production. Tata steel has also enlisted the research support of The Centre for Nano Science and Engineering (CeNSE) in Bangalore, India to investigate the potential sensor applications of the graphene material.
For Chandra the project has been ongoing for the last two-and-a-half years, and he says the development that has been made thus far has been very fast. “We’ve gone from a research curiosity and then to a research project in R&D to where we are now with a small production unit on the R&D level,” he added.
In addition, Chandra believes that the work at CeNSE could start producing tangible dividends from their research in as soon as a year from now. The material could enable glass to turn from clear to opaque with just the passing of current through it with the graphene providing the conductivity in the glass.
In the meantime, Chandra is looking for other collaborators, especially any organizations that can offer expertise and insight on how to scale up a steel production process that employs a graphene oxide for corrosion resistance.
Posted By Terrance Barkan,
Sunday, November 5, 2017
Updated: Sunday, November 5, 2017
Graphene, the world's first two-dimensional material, is many times stronger than steel, more conductive than copper, lightweight, flexible and one million times thinner than a human hair.
Graphene is set to improve the quality of life for many across the globe. Potential applications include inexpensive water purification systems; greener, more efficient cars and planes; flexible phones and even biomedical applications such as wound healing and cancer treatments.
Graphene’s commercial adoption will be accelerated by answering two key questions: what are the characteristics of commercially-supplied graphene? And how can they be used to best effect?
The establishment of common industrial metrics, regarding for example the number of layers or flake size, is crucial for the uptake of graphene-based technologies.
The National Graphene Institute at the University of Manchester has partnered with NPL to produce a guide, as part of NPL's good practice guide series, that aims to tackle the ambiguity surrounding how to measure graphene’s characteristics.
Material standardisation is crucial for industry uptake. There are many early adopters of graphene but without standardisation it is difficult for industry to be assured of the quality and properties of its graphene samples.
This guide seeks to address this gap and brings together the accepted measurement techniques in this area. It describes the high-accuracy and precision required for verification of material properties and will enable the development of other faster quality control techniques in the future.
Intended to form a bedrock for future interlaboratory comparisons and international standards, the guide will accelerate the development of graphene-enabled technology and improve the ability to produce graphene in a reliable and repeatable way.
Dr Andrew Pollard, lead author of the guide and Senior Research Scientist at NPL, commented:
"Although there are many ways to measure the properties of different types of commercially-available ‘graphene’, industry needs a standardised set of measurements. This will enable companies to select the type of material best suited to their needs by reliably comparing key characteristics, supporting the development of innovative new technologies based on graphene. This guide is the first step in this process, and as the basis of international measurement standards currently being developed, will provide measurement protocols that can be used in the interim."
James Baker, Graphene Business Director at the University of Manchester, said:
"This good practice guide has been developed by the NGI and NPL teams to allow the nascent graphene industry to perform accurate, reproducible and comparable measurements of commercially supplied graphene. This will address this important commercialisation barrier by providing users with a consistent approach to the structural characterisation of graphene whilst international measurement standards are being developed".
Nanotechnologies — Vocabulary — Part 13: Graphene and related two-dimensional (2D) materials
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies. The work of preparing International Standards is normally carried out through ISO technical committees. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The Graphene Council is proud to be a formal member of both, the ISO/ANSI TC 229 Nanotechnology Standards Development Group as well as the USNC Technical Advisory Group to IEC TC 113, Nano-Electrotechnologies.
Our focus is on the development of standards that will benefit suppliers, buyers and users. We firmly believe that clear standards will foster greater adoption of graphene and graphene related products.
Now, in a series of in-person interviews with several researchers at ICFO (the first of which you can find here), we are gaining better insight into how these technologies came to be and where they ultimately may lead.
The combination of graphene with quantum dots for use in optoelectronics stems in large part from the contributions of Gerasimos Konstantatos, a group leader at ICFO, who worked with Ted Sargent at the University of Toronto, whose research group has been at the forefront of exploiting colloidal quantum dots for use in a range of applications, most notably high-efficiency photovoltaics.
“Our initial expertise and focus was on actually exploiting the properties of solution-process materials particularly colloidal quantum dots as optoelectronic materials for solar cells and photodetectors,” explained Konstantatos. “The uniqueness of these materials is that they give us access to a spectrum that is very rarely reached in the shortwave and infrared and they can do it at a much lower cost than any other technology.”
Konstantatos and his group were able to bring their work with quantum dots to the point of the near-infrared wavelength spectrum, which falls in the wavelength size range of one to five microns. Konstantos is now developing these solution-based quantum dot materials to produce even more sensitive materials capable of getting to 10 microns, putting them squarely in the mid-infrared range.
“My group is now working with Frank Koppens to sensitize graphene and other 2D materials in order to make very sensitive photodetectors at a very low cost that are capable of accessing the entire spectrum, and this cannot be done with any other technology,” said Konstantatos.
What Konstantatos and Koppens have been able to do is to basically eliminate the junction between graphene and the quantum dots and in so doing have developed a way to control the charge transfer in a very efficient way so that they can exploit the very high mobility and transport conductance of graphene.
“We can re-circulate the charges through the materials so that with a single photon we have several billion charges re-circulating through the material and this constitutes the baseline of this material combination,” adds Konstantatos.
With that as their baseline technology, Konstantatos and his colleagues have engineered the quantum dot layer so instead of just having a passive quantum dot layer they have converted it into an electro-diode. In this way they can make much more complex detectors. In the combination of the graphene-based transistor with the quantum dots, it’s not just a collection of quantum dots but is a photodiode made from quantum dots.
“In this way, we kind of get the benefit of both kinds of detectors,” explains Konstantatos. “You have a phototransistor that has a very high sensitivity and a very high gain, but you also get the high quantum efficiency you get in photodiodes. It’s basically a quantum photodiode that activates a transistor.”
In addition to the use of graphene, the ICFO researchers are looking at other 2D materials in this combination, specifically the semiconductor molybdenum disulfide. While this material is a semiconductor and sacrifices somewhat on the electron mobility of graphene, it does make it possible to switch off the material to control the current. As a result, Konstantatos notes that you can have much lower noise in the detector with much lower power consumption.
In continuing research, Konstantatos hinted at yet to be published work on how all of this combination of quantum dots and graphene could be used in solar cell applications.
In the meantime, the work they have been doing with graphene and quantum dots is much further advanced than what they have yet been able to achieve with molybdenum disulfide, mainly because work has advanced much further in making large scale amounts of graphene. But as the processes for producing other 2D materials improves, there will be a real competition between all of the 2D materials to see which provides the best possible performance as well as manufacturability properties.
In any event, Konstantatos sees that the way forward with both quantum dots and 2D materials is using them together.
He adds: “I think we can explore the synergies in between different material platforms. There's no such thing as a perfect material that can do everything right. But there is definitely a group of materials with some unique properties. And if you can actually combine them in a smart way and make hybrid structures, then I think you can have significant added value.”
The use of graphene in the growing field known as plasmonics—in which the waves of electrons known as surface plasmons that are generated when photons strike a metallic structure—has been transforming the world of photonics and optoelectronics, enabling the possibility of much smaller devices operated by photons rather than electrons.
It’s worth providing a bit of background on the field of plasmonics before jumping to this latest research. The use of photons instead of electrons for something like an integrated circuit has the clear benefit that photons travel much faster than electrons, promising much faster devices. However, the use of light in these applications is limited by the relatively large size of wavelengths of light. Light is fast, but their wavelengths are much larger than nanometer-scale dimensions of most integrated circuits.
Plasmonics provides a way to convert that light—photons—into waves of electrons that can be tuned to have much smaller dimensions than those of light. The dimensions of these plasmon waves can be a hundred times smaller than the smallest wavelengths of light. This means that light can serve as the basis of photonic integrated circuits, but many more devices than that.
The field of plasmonics has really taken in off in the last half-decade, and ICFO has been at the forefront of a lot of that work, especially in using graphene to enable the effect. However, what Garcia de Abajo has proposed is a new theoretical approach to generate visible plasmons in graphene not from light but from tunneling electrons.
In research published in the journal ACS Photonics, Garcia de Abajo and his colleague Sandra de Vega have suggested that there are more efficient ways of generating surface plasmons on graphene than using an external light source and have instead shown through models that graphene plasmons can be efficiently excited via electron tunneling in a sandwich structure formed by two graphene monolayers separated by a few atomic layers of hexagonal boron nitride.
As mentioned, it’s possible to tune the size of the plasmon waves, especially graphene plasmons, which can be changed in size according to the amount of doping level (an addition of other materials). While high doping levels can push the wavelength of the graphene plasmons towards the visible range, these grpahene plasmons primarily reside in the mid-infrared region, which translates into a weak coupling between far-field light and graphene.
What de Vega and García de Abajo have proposed is a methodology for visible-plasmon generation in graphene that requires no light at all. Instead, plasmons are generated from tunneling electrons, which are electrons that are able to pass through a material on the quantum level that they could not otherwise pass through.
To achieve this photon-less plasmonics, the researchers propose a graphene–hexagonal boron nitride (hBN)–graphene sandwich structure. In their model, the hBN layer is 1-nm thick that is sandwiched between two graphene monolayers.
When the right amount of voltage (bias) is applied between the two graphene sheets, it produces tunneling electrons through the gap. The researchers discovered a particular voltage window in which the tunneling electrons lose energy through the excitation of a propagating optical plasmon rather than dissipate through coupling with the vibrations of the crystal lattice of hBN that carry heat, which are known as phonons, (low bias) or electron–electron interactions (high bias).
One of the side benefits of plasmonic devices that operate in this way—without the need for photons—can also be used in reverse as sensors. In this way when a change occurs in the graphene plasmon properties, that change could lead to a voltage readout.
An international team of researchers led by Professor Steven Conlan, Swansea University Medical School and the Centre for NanoHealth has won an international award for a graphene biosensor based diagnostic test for ovarian cancer which is quicker, more accurate, less expensive and portable.
The team developed a testing device which can diagnose ovarian cancer in a few minutes using a drop of blood. This portable technology is different from the ones currently in the hospital environment and allows for greater flexibility in terms of monitoring a patient even after she has already been diagnosed with ovarian cancer.
As well as the test being simple and fast the test does not require a technically-developed laboratory or a specialized technician to operate it which reduces costs and means that there isn’t a need for a centralisation of services. The device can also be used with other biomarkers to detect other types of disease.
Ovarian cancer research award Professor Conlan, together with colleagues Dr Sofia Teixeira (Swansea University College of Engineering), Drs Lewis Francis, Deya Gonzalez and Lavinia Margarit (from the Swansea University Medical School), and Dr Ines Pinto from the International Iberian Nanotechnology Laboratory, INL, Braga, Portugal have been recognised for their pioneering work with the award of the i3S Hovine Capital Health Innovation prize.
Professor Conlan said: “The Hovione prize will allow the team to initiate the process of moving our device from the lab to the patient. Whilst there is much work to be done, this is an important step towards the better and earlier diagnosis of patients with ovarian cancer. Cooperation between the two European centres has been key in realising this achievement.”
i3S Hovine Capital Health Innovation prize, created this year, aims at distinguishing innovative ideas in the area of health. The winners of the grand prize receive €35,000 in financing and services that include a market study, development of a business plan, technology validation by industrial experts, and support in setting up a company based on the winning technology.
The i3S-Hovione Capital Health Innovation Prize is supported internationally by the European Institute of Innovation and Technology (EIT-Health) and has partnerships with several entities, such as Bluecinical (PT), Patentree (PT), SRS Advogados (PT), Impact Science (UK), and ANI / MCTES (PT) through its Bfk Award.
The Graphene Council’s industrial partners span from North America to Europe and all the way to Australia. But our latest industrial partner hails from Hong Kong and as such represents the Council’s first Asian corporate partner.
It is sometimes difficult to learn how Asia-based graphene producers see the graphene marketplace and how they see themselves fitting into the overall scheme of things. So our interview with Mr. Ho, Chairman of Perfect Right Limited, a subsidiary of Oovao Powers Holdings Limited, provided us with a unique opportunity to learn about an Asia-based graphene producer that moved beyond marketing materials.
What we can learn from those marketing materials is that Perfect Right Ltd. developed its low-cost process for producing high-quality graphene this year. What you will learn in this interview is what that process is, how they are functionalizing their graphene and how and when they intend to move up the graphene value chain.
The details contained in this interview will provide us with key insights on how this company sees its place in the marketplace now and well into the future.
Q: Can you please tell us what kind of process you have developed for producing a high-quality graphene in bulk quantities, i.e. chemical vapor deposition, liquid-phase exfoliation, plasma, etc.?
We synthesize graphene with an arc-discharge method.The electric arc oven for synthesis of graphene mainly comprises two electrodes in the atmosphere of air. The cathode and anode are both pure graphite rods. As the rods are brought close together, discharge occurs resulting in the formation of plasma.
Q: How have you improved on one of these processes to make it produce a higher quality of graphene at bulk quantities?
We have enhanced and patented our new production method, including the modification of production equipment, which produces high quality graphene that retains graphene’s desired properties, using a low current to create the arc discharge, effectively lowering the cost of production significantly.Our solution is also scalable, and we are able to ramp up production of our high quality graphene in accordance with market demand.We already have full production lines running at our factory, and we plan to expand our production capability as demand for our high quality graphene ramps up.We are continuing to fine tune various parameters in the production process, resulting in a continuous improvement in the quality of the graphene being produced in both purity and domain size, as evidenced by independent lab test results. Our production process is cost effective and completely environmentally-friendly.
For what applications have you functionalized your graphene? I see that many applications of graphene have been identified on your website, but for what specific applications are you functionalizing your graphene?
We are focused on the functionalizing graphene in the areas of energy storage, supercapacitor, coatings, and focused on utilizing the conductive properties of graphene in various applications.We are currently working with organizations in academia and industry, developing promising applications in the areas mentioned above, and aim to have commercial applications which are ready for market within the next 12 to 18 months.
What is your business model, i.e. are you producing master batches of functionalized graphene for various device manufacturers or are you producing these functionalized graphene materials for your own device manufacturing? If so, what are those devices or technologies?
We currently have our scalable production lines producing high quality graphene for use in the applications being researched, working in collaboration with organizations in academia and industry to bring to market consumer ready solutions which maximizes the unique properties of graphene.Our business model is to solidify and scale our graphene production, and in lock step develop commercial applications using our high quality graphene.We believe graphene applications has so far eluded the wider consumer market due to the lack of high quality and stable graphene supply being made available at cost effective prices.We believe our production method is the solution, as we will be able to provide high quality graphene at prices which will make the consumer applications cost effective, leading to wider adoption of graphene in even more applications.
What are the greatest challenges your company currently faces in the marketplace, i.e. cautious customers unsure of a new material for their processes, a stable value chain, etc.?
We believe our challenges are twofold, product differentiation and application. There are numerous graphene producers in the market; however, there seems to be a wide range in terms of quality and supplies available.We have encountered customers who are either using low quality graphene, or graphene oxide in some cases, where they are not maximizing the potential of their products.As for application, we believe that is an issue that faces all companies in the graphene space.Until commercial applications of graphene enhanced products become widespread and the application of graphene in products better understood, we will continue to see a fragmented industry where end users are not able to maximize the potential of graphene in their products.
What do you see as the key to success for graphene establishing a foothold for itself in the marketplace, i.e. a ‘killer app’, standardization in graphene, etc.?
We believe standardization of graphene will go a long way towards the adoption and wide spread use of graphene.Through our market research and interaction with academia, investment funds, and potential end users, one common theme is that there is a wide range of graphene products already in the market, but the lack of standardization makes it very hard for users to compare products, or to even secure a stable supply for their own use.Another milestone is to have a wide spread consumer facing application where the advantages of using graphene in that product is immediately recognizable.Graphene has been in the news for some time, however there are still no breakthroughs in the areas which graphene is known to be good for, e.g. energy storage, applications taking advantage of its conductivity, etc.
Where do you see your company in the next five years?
We see ourselves as being one of the premier suppliers of high quality graphene in the Asia region, and also an enabler of the commercialization of graphene enhanced products, through our partnerships with academia and industry players.We aim to have graphene enhanced products on the market within the next two years, and will focus on projects where the successful commercialization of that product will help push the entire graphene industry forward.
Complimentary metal-oxide semiconductors (CMOS) have served as the backbone of the electronics industry for over four decades. However, the last decade has been marked by increasing concerns that CMOS will not be able to continue to meet the demands of Moore’s Law in which the number of transistors in a dense integrated circuit doubles approximately every two years. If CMOS is going to continue to be a force in electronics, it will become necessary to integrate CMOS with other semiconductor materials other than silicon.
In research described in the journal Nature Photonics, the ICFO researchers combined the graphene-CMOS device with quantum dots to create an array of photodetectors.
While the photodetector arrays could enable digital cameras capable of seeing UV, visible and infrared light simultaneously, the technology could have a wide range of applications, including microelectronics to low-power photonics.
“The development of this monolithic CMOS-based image sensor represents a milestone for low-cost, high-resolution broadband and hyperspectral imaging systems" said, Frank Koppens, a professor at ICFO in a press release.
Koppens, who The Graphene Council interviewed back in 2015, believes that "in general, graphene-CMOS technology will enable a vast amount of applications, that range from safety, security, low cost pocket and smartphone cameras, fire control systems, passive night vision and night surveillance cameras, automotive sensor systems, medical imaging applications, food and pharmaceutical inspection to environmental monitoring, to name a few."
The researchers were able to integrate the graphene and quantum dots into a CMOS chip by first depositing the graphene on the CMOS chip. Then this graphene layer is patterned to define the pixel shape. Finally a layer of quantum dots is added.
“No complex material processing or growth processes were required to achieve this graphene-quantum dot CMOS image sensor,” said Stijn Goossens, another researcher from ICFO in Barcelona. “It proved easy and cheap to fabricate at room temperature and under ambient conditions, which signifies a considerable decrease in production costs. Even more, because of its properties, it can be easily integrated on flexible substrates as well as CMOS-type integrated circuits."
The graphene-enabled CMOS chip achieves its photoresponse through something called the photogating effect, which starts as the quantum dot layer absorbs light and transfers it as photo-generated holes or electrons to the graphene. These holes or electrons move through the material because of a bias voltage applied between two pixel contacts. The photo signal triggers a change in the conductivity of the graphene and it is this change that is sensed. Because graphene has such high conductivity, a small change can be quickly detected giving the device extraordinary sensitivity.
Andrea Ferrari, science and Technology offficer of the Graphene Flagship added: "The integration of graphene with CMOS technology is a cornerstone for the future implementation of graphene in consumer electronics. This work is a key first step, clearly demonstrating the feasibility of this approach.”
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.
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!
This is an authorized reprint of a recent publication in Advanced Energy Materials journal (Impact Factor: 16) (http://dx.doi.org/10.1002/aenm.201601216), by Stuart M. Holmes (Reader) and Prabhuraj - (PhD student - http://www.prabhuraj.co.uk/) from the School of Chemical Engineering and Analytical Science, University of Manchester in collaboration with the School of Physics, reporting the usage of 2D materials in operating direct methanol fuel cells, showing zero resistance to protons enhancing cell performance, thereby opening the bottle neck for commercialization of fuel cells.
The content published is the sole responsibility of the authors.
Fuel cells are an interesting energy technology for the near future, as they aid in production of sustainable energy using hydrocarbons as fuels, such as methanol, ethanol, acetone etc by a simple oxidation-reduction reaction mechanism.
Among different liquid fuels, methanol is attractive as it has a higher energy density (compared to lithium ion batteries and hydrogen) and other features such as ease in handling, availability etc. Hence methanol fuel cells find their potential use in laptop chargers, military applications or other scenarios where the access to electricity is difficult.
However the wider spectrum of commercial potential for methanol systems is greatly hindered by methanol cross over occurring in the membrane area of fuel cells. This is defined as the passage of methanol from anode to the cathode through the membrane, hence creating short circuit and greatly affecting the fuel cell performance.
This is mitigated by using barrier layer, in addition to the membrane used.
Figure 1: Schematic illustration of methanol fuel cell and structure of graphene
So far many materials have been used as a barrier layer in methanol fuel cells, where the proton conductivity is balanced with the methanol cross over. Proton conductivity is one of the dominant factors, where slight reduction in proton conductivity can influence the fuel cell performance to a large extent. All the materials reported in the literature to date have seen a reduction in proton conductivity though methanol cross over is reduced.
It is known that Andre Geim and his co-workers (Nature, A.K. Geim et.al 2014), discovered proton transfer through single layer graphene and other 2D materials. Also graphene is known for its dense lattice packing structure, inhibiting the passage of methanol and other hydrocarbon based molecules across the membrane. However the actual application of these 2D materials in fuel cell systems has not yet been realized.
In this Advanced Energy Materials paper, the researchers have used single layer graphene and hBN, formed by chemical vapour deposition method, as a barrier layer in the membrane of methanol fuel cells. They have reported that this thinnest barrier layer ever used before shows negligible resistance to protons, at the same time reducing cross over, enhancing the cell performance by 50%. This is of significant interest, as this would lead to usage of 2D materials in fuel cells.
Based on the results of the research obtained, researchers have been granted EPSRC (Engineering and Physical Sciences Research council grant “Adventurers in Energy grant”) to pursue further research in this field. They have shown that as the surface coverage of the 2D material on the system improved, the performance improved. This would lead to the usage of fuel cells, operating with high concentrated methanol fuels, as the current fuel cells suffer from cross over phenomena, with increased concentration.
Moreover, this would pave the way for a membrane-less fuel cell system operating with higher efficiency. This technology could further be extended to other fuel cells types namely hydrogen fuel cells. Hydrogen fuel cells suffer from the usage of high cost humidifier, where the membrane needs to be humidified for improved proton conductivity. Whereas graphene, as reported in earlier studies, showed improved proton conductivity with temperature, without the need for humidifier systems. The future prospect could be realized in such a way that the fuel cells will make significant contribution to the future energy demand.
Ever since nanomaterials made their first tentative steps into commercial markets, the early targets were in sporting goods. There is a pretty good catalogue of the different nanomaterials and the various sporting good products that they have been used for in a paper published in the Center for Knowledge Management of Nanoscience and Technology’s (CKMNT) from which an excerpt is provided here.
The CKMNT report was compiled over three years ago and what is conspicuously absent from its list of nanomaterials for sporting goods is graphene. Carbon nanotubes are there as well as carbon nanofibers for bicycle frames—an application I had a brief foray into seven years ago when I tried to discern whether there was any appreciable benefit to using carbon nanofibers than just run-of-the-mill fillers in the composite. But graphene just a few years back didn’t apparently make a blip on the radar.
That has all changed, of course, with graphene finding high-profile applications in tennis racquets and skis, both of which are produced by Head. However, I was more intrigued by the recent application of graphene in cycling since I am an avid cyclist myself.
The application that has gotten a lot of press is the adoption of graphene by venerable Italian cycling tire manufacturer Vittoria when it launched graphene-enabled tire dubbed G+ or Graphene Plus. You can see a promotional video below, but the main advantages of the graphene-enabled tires are supposed to be lighter weight, greater strength and durability. Of course, every tire is supposed to provide good grip and low rolling resistance and this new series of tires claims to tick those boxes as well.
My question was whether graphene could really offer much benefit over conventional reinforcing fillers like carbon black, or were we just looking at a bit of marketing and extra price per tire. So, I asked an industry expert in using graphene with different compounds, who asked to remain anonymous, if much benefit could be derived from using graphene in an application like this.
Vittoria has made it known that they are using a graphene platelet material for their tires. My source explained rubber compounding has so many variables that the kind of graphene platelet they are using would depend on the elastomer system, other parts of the filler system, protection system, process aids, curing package.
He added that as important as the specifications of the graphene are how they are processing the material is equally as important. Conventional reinforcing fillers such as carbon black are usually compounded into the raw rubber in mixers prior to vulcanization. Graphene, he explained, could be added into the product through a similar approach. However there are other routes to introducing graphene into the rubber matrix, which he was not at liberty to discuss.
The aims of modifying tire rubber formulations have traditionally been aimed at improving the so-called "tire triangle" of properties. This triad includes: Low rolling resistance, Abrasion resistance and Wet-traction control.
While graphene has been thought to improve these above properties, my source concedes that no matter what reinforcing fillers are used it is usually very difficult to obtain improvement to all three properties of the tire triangle simultaneously, there is usually a trade-off in performance between these properties.
My source also points out that carbon nanotubes have long been expected to deliver the same type of improvements as graphene to tire performance but have never managed to gain a market foothold.
In the UK-based Cycling Weekly, the question of graphene in tires was given a lengthy discussion in which they interviewed one of Vittoria’s competitors, Continental.
“In the past we did some trials with graphene in the casing and tread of our tyres,” said Christian Wurmbäck, head of product development bicycle tires at Continental in the interview with Cycling Weekly. “However, although the directionality of the compound brought some benefits to the casing, the development of our Carbon Black compounds [which are said to use carbon nano particles] is at a higher level, so there was no need to jump back on graphene.”
It would seem the jury is still out on how much of a difference can make on improving your bicycle tires. I may just have to go and do a test, if I can get someone to send me a couple for testing purposes.