Thursday, August 15, 2013

Graphene: the future of materials

MATERIALSA perfect materials combine the lightness of carbon fiber, the flexibility of an elastomer and hardness of diamond. Impossible? No ... well, at least not entirely. I present graphene, a material born to be perfect. While it became known for more than 80 years, I can assure you that we still have a long road ahead in the world of materials.Graphene is a substance composed of pure carbon atoms with regularly arranged in a hexagonal pattern similar to graphite, but a sheet of one atom thick. It is very light, a sheet of 1 square meter weighs just 0.77 milligrams.
The surge of scientific interest in graphene can give the impression that it is a new material. Actually is known and has been described for more than half a century. The chemical bonding and structure were described during the 1930s. P. R. (Philip Russell) Wallace calculated for the first
time (in 1949) the band electronic structure. When graphene paid little attention for decades to think that was a thermodynamically unstable material as it was thought that thermal fluctuations destroy the order of the crystal resulting in the 2D crystal to melt. In this light means the revolution meant that Novoselov and Geim consiguiesen isolate graphene at room temperature. The Nobel Prize in Physics 2010 was awarded to Andre Geim and Konstantin Novoselov for their groundbreaking discoveries about the two-dimensional material graphene.
Among the outstanding properties of this material include:
· It is very flexible
· It is transparent
· Self-cooling
· High thermal and electrical conductivity.
· High elasticity and toughness.
· Very high hardness: 200 times greater than that of steel, almost equal to that of diamond.
· Chemical reaction with other substances to produce compounds of different properties. This gives it great potential for development.
· Support of ionizing radiation.
· Great lightness, like carbon fiber, but more flexible.

· Low Joule effect: less driving heats the electrons.
· For a given task than silicon, less electricity.
Graphene properties are ideal for use as a component of integrated circuits. It is equipped with high carrier mobility and low level of 'noise'. This allows it to be used as channel field effect transistors (FET). Furthermore, it is known for its ability to produce the first flexible displays on the market.
The difficulty of using graphene lies in the production of the same material in the appropriate media. It also has a great disadvantage compared to silicon (conductor par excellence): graphene has no band resistivity essential property that is inherent to silicon. This means that graphene can not conduct electricity: can not turn off.

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