A look at graphene and the wide range of applications for these groundbreaking new materials.
Graphene’s outstanding mechanical and electronic properties make it an extremely promising candidate for future use in electronics, composites, sensors, energy storage devices. The “graphene family (single layer graphene, SLG, few layer graphene, FLG, graphane, graphene nanoribbon, GNRs, reduced graphene oxides, RGO, graphene oxide, GO, epitaxial graphene, EG) is being employed in a variety of hybrid structures. Most graphene producers currently produce graphene nanoplatelets and graphene oxide and plan to scale-up production considerably over the next 18 months. Producers are generally small, start-up companies who have witnessed an explosion in demand for their materials from a variety of industries. Companies such as IBM and Samsung are pursuing applications for graphene in electronics and optics, which are likely only to be realized in the medium to long-term. Most near-term demand is for composites and coatings for application in the automotive, plastics, coatings, construction, metals, batteries, aerospace and energy markets. Barriers to widespread industry uptake mirror carbon nanotubes: functionalization and dispersion; mass manufacturing at an acceptable cost; need for application partnerships; and health and safety issues. Cost per ton for graphene is likely to undercut carbon nanotubes. Main producers such as Angstron Materials, XG Sciences and Vorbeck are all planning large production increases to allow them to offer materials for under $40kg.
Sensors
Graphene is considered to be an excellent sensor material. It is extremely sensitive to the presence of adsorbed atoms and molecules (either physisorbed or chemisorbed on the surface) and, more generally, to defects such as vacancies, holes and/or substitutional dopants. Graphene has shown promise for applications such as ultra-sensitive gas, bio and chemical sensors.
Composites
Graphene has attracted large attention as a reinforcement material for polymers due to its ability to modify electrical conductivity, mechanical and gas barrier properties of host polymers and its potentially lower cost than carbon nanotubes. Advantages of graphene over carbon nanotubes stem from easy access to the graphitic precursor material, the cost, and the scalable method.
Energy
A number of companies are developing energy storage applications for graphene where it could potentially replace the graphite electrodes found in batteries, supercapacitors and fuel cells. Ultra-thin sheets of graphene can be fabricated on lithium-ion battery electrodes to yield vastly shorter recharge times. In fuel cells, both bi-polar plate and electrode efficiencies can be improved with the incorporation of graphene.
Composites
Graphene has attracted large attention as a reinforcement material for polymers due to its ability to modify electrical conductivity, mechanical and gas barrier properties of host polymers and its potentially lower cost than carbon nanotubes. Advantages of graphene over carbon nanotubes stem from easy access to the graphitic precursor material, the cost, and the scalable method.
Electronics
Graphene has remarkable electronic properties, with an extraordinarily high charge carrier mobility and conductivity. Graphene is an excellent conductor, and it transports electrons tens of times faster than silicon does. These properties make it an ideal candidate for next generation electronic applications, in high-speed transistors.
Aerospace
Graphene platelets are being developed for aerospace applications including aircraft braking systems (carbon/carbon composites), thermal management, electromagnetic interference (EMI), radio frequency interference (RFI), electrostatic discharge (ESD), lightning strike and composite applications. Near-term applications are likely in EMI shielding coatings.
Coatings
Graphene shows excellent potential as a protective layer, due to its exceptional thermal and chemical stability and impermeability. Its excellent performance as a passivation layer has been demonstrated. The surfaces of sp2 carbon allotropes form a natural diffusion barrier, thus providing a physical separation between the protected surface and reactants. Graphene is also resistant to attack by many powerful acids and alkalis.
Automotive
Graphene platelets are under investigation for automotive components including fuel systems and electrostatic spray painting (ESP). Electrically-conductive graphene additive polymers show sufficient electrical conductivity to be painted directly by ESP. By allowing direct ESP of polymers 18 percent of volatile organic compounds are eliminated from the process and costs can be reduced.
Communications
Graphene is under development in communications for applications in amplifiers, frequency multipliers and high-speed photodetectors. Single-transistor amplifiers benefit from the “ambipolar” nature of graphene, allowing for its use in both wireless and audio applications. Graphene is an excellent conductor of electricity and heat and transistors made from graphene have a very high cut off frequency above 100 GHz .
