Graphene … The Disruptive Material of the 21st Century.
What is the Extraordinary Material Graphene?
Carbon naturally occurs in two forms (allotropes) - graphite and diamond. What makes both of these extremely different is the 3D arrangement of the carbon atoms in each mineral. In diamonds the atoms are tightly bonded in tetrahedrons, whereas in graphite, the carbon atoms are bonded tightly in a 2D hexagonal honey comb lattice (layer), with each layer held to each other by weaker forces (van de Waals bonds). These weaker forces can be broken to yield a single layer which is only one carbon atom thick. This single layer is known as graphene. It is this unique structure which gives graphene its extraordinary properties which make it the thinnest, lightest, and strongest material known to man.
Graphene was first isolated in 2004 at the University of Manchester by Professor Andre Geim and his college Professor Kostya Novoselov by removing some flakes from a sample of lump graphite with sticky tape. They repeatedly separated the graphite flakes until one flake remained that was just one carbon atom thick. For this they were awarded the Nobel Prize in Physics in 2010.
Today there is a global race to develop new products with enhanced performance using this disruptive material which can revolutionise many things that we use in our everyday life.
What is graphene oxide (GO)?
Graphene oxide is a chemically derived form of graphene which is prepared by the oxidation of graphite which increases its interlayer spacing, facilitating exfoliation. GO is a single sheet of graphene which also contains oxygen and hydrogen functional groups on its surface and edges.
What is reduced graphene oxide (rGO)
When additional processes are applied to graphene oxide to remove the oxygen and hydrogen content. This is known as reduced graphene oxide (rGO).
Properties of Graphene:
Methods to Produce Graphene
Top-down begins with natural graphite and uses either mechanical or chemical exfoliation processes to produce graphene or graphene oxide, respectively.
Possible exfoliation methods include chemical exfoliation, sonification, and intercalation which is the insertion of molecules or ions to produce a single sheet.
Graphene oxide involves the use of oxygen to separate the carbon sheets by using oxidizing agents to product graphene oxide (GO). This is then dispersed in water to yield individual graphene sheets.
Reduced Graphene Oxide involves the reduction of oxygen and hydrogen by various methods such as chemical, thermal or microwaves.
Functionalized Graphene is formed when functional groups are added onto the surface of the 2D layer of graphene by chemical methods. Both covalent and non-covalent methods can be used to functionalize graphene oxide materials.
These methods utilize natural graphite.
The other way to produce graphene is bottom-up: by molecular growth from small molecular carbon precursors by Chemical Vapor Deposition (CVD) or epitaxial growth on a substrate, pyrolysis and others.
These methods utilize other carbon-bearing materials such as hydrocarbon gases which are burnt to produce a very fine carbon soot.
Graphene Products on The Market Today
Siren Technology security smart packaging with graphene based Ink.
HEAD graphene tennis rackets (YouTek Graphene Speed series).
Vittoria- bicycle race wheels that are produced from graphene-enhanced composite materials.
Biolin Scintific along with ICN2 Nanobioelectronics and Biosensors Group have added graphene oxide (GO) sensors to a line of products.
Spanish paint producer Graphenstone produces coatings that are enhanced with graphene for both indoor and outdoor applications.
ORA, Canada-based developer of graphene-enhanced audio equipment, launched a kickstarter crowd-funding campaign to develop and produce graphene-enhanced wireless bluetooth headphones.
The Sixth Element graphene-enhanced tires have been developed with Shangdong Hengyu technology.
Germany-based Skeleton Technologies has developed “curved graphene” based supercapacitors.
Chinese producers have developed lightweight, self-sterilizing graphene-enhanced shoes.
Callaway also produces graphene infused golf balls.
According to Global Market Insights
The largest sectors in the global graphene market according to IDTechEx Research analysts are: