What is Graphene and how is it Made

The element carbon is one of the most versatile elements. Life as we know it would not exist without all its organic compounds. The existence of carbon in the forms of graphite and diamond is well known and, in 1985, these were joined by the odd soccer ball shaped forms Buckminsterfullerenes or buckyballs. The most recent form of carbon, made in 2004, is graphene.

Graphene is made of atom thick sheets of carbon in a hexagonal array. The first graphene samples formed were produced by pulling atom thick layers from a sample of graphite using sticky tape. According to Graphene industries people using a standard graphite pencil have probably made graphene as some of the marks formed by a pencil are just an atom thick.

Graphene films are flexible and extremely strong despite being so thin. They have the potential for use as support films for biological samples held in the beam of a transmission electron microscope.

They also have interesting and potentially useful electrical properties. Transistors made from samples of graphene work in the gigahertz range. Researchers believe that transistors made of graphene will eventually work far faster possibly in the terahertz range. Currently the graphene films produced are too small to allow the production of integrated circuits.

A single atom or molecule of a gas impacting the surface of a graphene film alters its electronic properties. This allows the usage in gas detectors sensitive enough to react to a single gas atom.

Graphene is chemically inert and is not attacked by hydrofluoric acid or ammonia. If sufficient quantities can be, produced graphene has the potential to form an inert protective coating for equipment used in chemically harsh environments.

Carbon nanotubes are rolled up sheets of graphene. The strength of these nanotubes is such that it has been suggested that cables made from them could be used to support an elevator into space. (Source Graphene Industries).

The biggest problem with the industrial usage of graphene is one of producing larger sheets of the substance. The sticky tape method produces very small samples of high quality graphene. Researchers in Seoul, Korea produced samples adhered to thin pieces of nickel, which were then dissolved to leave the graphene films.

In August 2009 researchers from The McCormick School of Engineering and Applied Science, North-western University, Illinois announce a new production method for graphene films. They used a camera flash to oxidize graphite oxide to produce a graphene film. By firing this flash through an etched photographic film a circuit of graphene could be produced this method has the potential form the mass production of graphene. Research is continuing on the production and other aspects of graphene technology

A film showing representations of the graphene molecule and carbon nanotubes is available on YouTube

Reference sources:

Graphene industries

Physics world.com

BBC News

Nano Technology Now