First Graphite - What is Graphene?

Graphene has been talked about in glowing terms with scientists suggesting confidently it is the key to the future of almost all materials. So revolutionary are its qualities they even talk of the “graphene age”.

Graphene is a natural material which is the basic building block of graphite, achieved when the thickness is reduced to less than 10 atoms. Though it was “discovered” in the 1940s, it took until 2004, before scientists figured out how to isolate it from graphite particles, using the simple “scotch tape” exfoliation method. 

Since then there has been tremendous interest in graphene with research scientists demonstrating its suitability for combination with a vast range of materials, to greatly enhance the performance of those materials. There has also been an explosion in the number of patents being taken out as industry has been preparing for the start of the new and deeply disruptive “graphene age”. The key properties of graphene that industry is seeking to employ are as follows:

 

Thinnest material

It is only one carbon atom in
thickness i.e. only ~0.345 nm
thick.

 

Impermeable

It is completely impermeable.
Even helium atoms can’t pass
through it. 

 

 Optical properties

One atom thick layer sheets
absorb ~2.3% visible light,
making it transparent.

 

Light and stretchable

It weighs only 0.77 milligrams
per square meter and is
stretchable up to 20% of its
initial length. It has the largest
volume to surface area ratio of
any material.

 

 

Other qualities

Self-repairing - graphene can
self-repair holes in its sheets
when exposed to molecules
containing carbon. Reactive -
it is the most reactive form of
carbon.

 

 

Thermal conductivity

It is a perfect thermal 
conductor (over 5,000 W/mK),
being 5x the conductivity of 
graphite. It conducts heat in 
all directions i.e. it is an 
isotropic conductor.

 

 

Electronic properties

It has the highest electrical 
current density (one million 
times that of copper) and the 
highest intrinsic mobility (100x 
that of silicon). It has a lower 
resistivity than any other know 
material, at room temperature.   




Stronger than steel

One of the hardest materials in 
the world, harder than diamonds
and 200x stronger than steel
(1,100TPa/125 GPa) of the same
thickness but very flexible and
won’t break. For example, a
graphene sheet 1 m2 in size
could support a 4 kg cat, but
would weigh only as much as
the cat’s whiskers (1).

 Chemical properties

It is an inert material and does 
not readily react with other 
atoms. However, it can 
“absorb” different atoms and 
molecules, leading to changes 
in its properties. It can be 
functionalised by several 
different chemical groups, 
resulting in different materials 
such as graphene oxide and 
fluorinated graphene.

 

 Useful Links Describing Graphene and its Potential

 

AXINO presents the new graphene producer First Graphite Limited (ASX: FGR)