Graphene Research Paper

GRAPHENE

Vinuta, Vidya Shree G, Sahana Sheshagiri Shanbhag

Department of Science and Humanities, PESIT Bangalore South Campus,

Hosur main road, Bangalore 560 068 ABSTRACT

Graphene is pure carbon in the form of a very thin, nearly transparent sheet, one atom thick. It is remarkably strong for its very low weight, 100 times stronger than steel, hard as diamond, million times thinner than paper and it conducts heat and electricity with great efficiency. Graphene with the unique combination of bonded carbon atom structures with its myriad and complex physical properties is poised to have a big impact on the future of material sciences, electronics and nanotechnology. Owing to their specialized structures and minute diameter, it can be utilized

Chemical properties

Graphene is the only form of carbon (and generally all solid materials) in which each single atom is in exposure for chemical reaction from two sides (due to the 2D structure). It is known that carbon atoms at the edge of graphene sheets have special chemical reactivity, and graphene has the highest ratio of edgy carbons (in comparison with similar materials such as carbon nanotubes). In addition, various types of defects within the sheet, which are very common, increase the chemical reactivity.

2.Mechanical Properties

Another of graphene’s stand-out properties is its inherent strength. Due to the strength of its 0.142 nm-long carbon bonds, graphene is the strongest material ever discovered, with an ultimate tensile strength of 130,000,000,000 Pascal (or 130 gigapascal). Not only is graphene extraordinarily strong, it is also very light at 0.77milligrams per square metre (for comparison purposes, 1 square metre of paper is roughly 1000 times heavier). It is often said that a single sheet of graphene (being only 1 atom thick), sufficient in size enough to cover a whole football field, would weigh under 1 single gram. What makes this particularly special is that graphene also contains

zigzag Fig.2(c). armchair

4.Electronics Properties Graphene is a semi-metal or zero-gap semiconductor. Four electronic properties separate it from other condensed matter systems. One of the most useful properties of graphene is that it is a zero-overlap semimetal (with both holes and electrons as charge carriers) with very high electrical conductivity. Typical strain-stress curves of the single GO and graphene fibre. The inset photograph showing the testing state of the single fibre.

5.Optical Properties

Graphene’s ability to absorb a rather large 2.3% of white light is also a unique and interesting property, especially considering that it is only 1 atom thick. This is due to its aforementioned electronic properties; the electrons acting like massless charge carriers with very high mobility. A few years ago, it was proved that the amount of white light absorbed is based on the Fine Structure Constant, rather than being dictated by material specifics. Adding another layer of graphene increases the amount of white light absorbed by approximately the same value (2.3%). Graphene’s opacity of πα ≈ 2.3% equates to a universal dynamic conductivity value of G=e2/4ℏ (±2-3%) over the visible frequency