Graphene- The Wonder Material.

Graphene was first demonstrated by Andre Geim and Konstantin Novoselov, two physicists from the University of Manchester, in 2004 for which they had won Noble Price in 2010. Scientists argued that strictly 2 dimensional crystalline materials were thermodynamically unstable and could not exist. Graphene is a single layer (monolayer) of carbon atoms, closely bound in a hexagonal honeycomb lattice. It is an allotrope of carbon in the form of a plane of sp2-bonded atoms (though carbon has a valency of four, due to similar reasons as that of graphite as it is derived from it) with a molecular bond length of 0.142 nanometres.

Strength of Graphene

Layers of graphene stacked on top of each other form graphite, with an interplanar spacing of 0.335 nanometres, these layers are held by Van der Waals force. The separate layers of graphene in graphite are held together by Van der Waals forces, which can be overcome during exfoliation of graphene from graphite. There are about 30,00,000 layers of graphene in 1 millimetre of graphite. In short, graphene is harder than diamond despite being more elastic than rubber hundreds of times harder than steel despite weighing much lesser than aluminum.

Graphene is the thinnest compound known to humans at present which is one atom thick, the lightest material known (with 1 square meter of monolayer of graphene weighing around 0.77 milligrams), the strongest compound discovered ( hundreds of times stronger than steel with a tensile strength of 128.56 GPa). To put it into perspective, atom-thick graphene can and hold a football over it. Researchers have shown that even adding a trace amount of graphene to metal, plastic or any other materials can increase its strength to a great extent. Such material will find its use in the aerospace industry, construction industry, or consumer electronics and many more uses yet to be found.

Electrical and thermal properties

Graphene has the most heat-conducting capability than any other materials known to us. It conducts heat two times better than the diamond. As graphene is also strong and light, thus it is a great material for making heat-spreading solutions, such as heat sinks or heat dissipation films. Now coming to its electrical capabilities, its electrical conductivity is 13 times more than that of copper and its electron mobility is about 100 times more than that of silicon. The QHE (Quantum Hall Effect) is another factor indicating graphene's outstanding electronic quality. Because the temperature range of the QHE for graphene is 10 times broader than that of other 2 dimensional materials known to us, the QHE in graphene can be seen at room temperature. Such material will find its use in transmission lines, since its area to volume ratio is very high, it can be a very good alternative for high energy storage batteries.

     

Other important properties of graphene are its uniform absorption of light across the visible and near-infrared parts of the spectrum (absorptivity ≈ 2.3%) and its potential suitability for spin transport. It is impervious to an extent that even the smallest atom that is helium can't pass through a defectless monolayer of graphene! This can find applications in the making of laboratory protective gear as it can easily prevent the entry of viruses inside it.

 
           

 Then what is the reason that it has not entered the market despite having such a vast application, the answer lies in the cost of the material. At present, the cost of production graphene lies anywhere between 90$ to 105$ per gram depending upon the quality of the material. This seems to be a very huge amount but any material at its initial stage posses a high price due to a lack of technology to mass-produce that material but as technology advances the price reduces drastically. The same is with graphene, there are few start-ups and companies which are working towards bringing down the cost of production. One such company is Real Graphene which has already launched its graphene power banks. Another company that has made some serious advancements is Vorbeck Materials, they have already launched their graphene-based products in the market.