materials research | Graphene and nanofi llers
use in electronic devices, for instance in fl exible touchscreens for mobile phones, while its stiffness and strength, electrical conductivity and impermeability open up applications in nanocomposites, the fi rst commercial one being in a Head tennis racket. Professor Karl Coleman of Applied Graphene Materials (AGM) and the University of Durham cited forecasts that the world graphene market will increase 20 times in volume to 400 tonnes and 100-fold in sales to US$1 billion from 2012 to 2017. It is predicted that paints and coatings, oils and lubricants, and food and product packaging will be early leaders, followed by composites, thermal management and displays, then photovoltaics, supercapacitors, printed electronics, computing, cables and batteries.
Martin Williams of Haydale used these illustrations to show the different forms of nano-carbons
Graphene (C62 H20 ) and, to a lesser degree, CNTs were
the major subjects of interest at the workshop. Defi ned by another speaker as “a single layer of sp2
-hybridised
One of the fi rst applications of graphene- based nano-
composites is in Head tennis rackets
carbon atoms arranged in a honeycomb structure”, graphene is the newest and fi rst true 2D carbon nano- material. It is also the basic reference building block for graphitic nanomaterials of all other dimensions and can be combined with single- and multi-wall CNTs in some applications. The isolation of single graphene layers was fi rst published by two now knighted professors, André Geim and Kostya Novoselov, at the University of Manches- ter in the UK in 2004. This discovery earned them the Nobel Prize for Physics in 2010. Graphene is now the subject of over 7,000 patents, though only 50 from the UK, as opposed to about 2,200 from China, 1,700 from the US and 1,200 from South Korea. Samsung alone is said to be spending around $500 million on R&D into graphene in mobile phones.
Huge claims are made for graphene. It is the thinnest and strongest material on Earth and 200-300 times stiffer than steel, while having the highest heat conduc- tivity of any material (about 500 Wm-1
K-1 v-1 s-1 ),
higher electrical conductivity than copper (200,000 cm2
) and chemical stability at up
to 400°C. It is also 97.7% transparent, 20% stretchable and an impermeable barrier to all gases.
“The issue is: what can we do with it?” Kemp said. Many potential applications have been mooted. Its excellent electronic properties make it a strong candidate for
28 COMPOUNDING WORLD | February 2014
Dr Bojan Boskovic, director of Cambridge Nanoma- terials Technology, added that graphene nanomaterials have huge potential in both aerospace applications (engine control systems, engine components, composite brake discs, sensors, etc.) and automotive components (carbon fi bres for the body, windows and windscreens, brakes, pressure gauges, fuel cells, batteries, etc.). However, there are many barriers to wider market
development. As several speakers noted, the graphene market is fragmented, with many different materials at different price points. There are no clear standards or obvious process winners yet and certainly no ‘killer app’; on the contrary, the extreme multi-functionality of graphene means that it is not easy to know where research will go. Activity in the fi eld is still essen-
tially research-led and there are some big gaps in the supply chain; even when a platform adopts a material, it cannot currently be sure that material will be
commercially available, though the NCC and other organisations are
working to address such challenges. The example of the safety issues raised against CNTs, plus public
distrust and genuine toxicology issues, may also hold them back. Moreover, graphene faces well-entrenched incumbent technologies, notably ITO (indium tin oxide) and silicon in electronics. Some consequently
believe that it will not replace silicon for 30 years. And, because in most other applications, it will be loaded into matrices of other materials, graphene’s astonish- ing properties will not always be evident in practice. Nonetheless, no-one seriously doubts the potential of nanocarbons in general and graphene in particular. Probably the most immediate potential lies in
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