Dream material that receives world’s attention, Graphene
Graphene is
New material shaped as a honeycomb that isolated from graphite
(commonly used as a pencil core), and its thickness is 2.2 nm
Graphene is one of the allotropes of carbon, and is a structure in which carbon atoms gather to form a two-dimensional plane. Each carbon atom forms a hexagonal lattice and shaped as carbon atom is located at the vertex of the hexagon. The shape of graphene is also called as honeycomb structure or honeycomb lattice. Graphene is a thin film made of one atom thick(1 nm is 1/𝐵𝑖𝑙𝑙𝑖𝑜𝑛 of a meter), about 2/𝐵𝑖𝑙𝑙𝑖𝑜𝑛 of a meter, which is extremely thin and has high physical and chemical stability.
Other allotropes of carbon include graphite, carbon nanotubes, fullerenes, diamonds and etc. Graphene has the same bonding structure with graphite due to its of the thickness of one layer atom, yet it has significantly different properties from graphite composed of several layers.
Graphene is attracting attentions because of its following outstanding characteristics. It has a very high intrinsic electron mobility of 200,000 〖𝑐𝑚〗^2/V • s, a high thermal conductivity of ~ 5000 W/m • K and a Young's modulus of ~ 1.0 TPa. The theoretical specific surface area is also very large. Since it is composed of one layer, the absorption of visible light is very low allowing the transmittance of light having a wavelength of 550nm was confirmed to be 97.7%.
Graphene can deliver 100 times more electricity than copper and can move electrons 100 times faster than single crystal silicon which is mainly used as a semiconductor. The strength is more than 200 times stronger than steel and the thermal conductivity is more than twice higher than diamonds which known as to have the best thermal conductivity. Due to its excellent elasticity, does not lose its electrical properties even when stretched or bent. Graphene is regarded as a material that surpasses the carbon nanotube which is spotlighted as a new material of the new-generation, and it is called "the nanomaterial of dream.“
The existence of graphene has been known for a long time and scientists have been working on it for decades to make it. In 1962, scientists made a very small amount of graphene by using a pencil lead or graphite and made the first observation through an electron microscope, but no further research was conducted. In 2004, graphene was re-illuminated when it was successfully peeled off from graphite using scotch tape by Andre Geim and Professor Novoselov of the University of Manchester.
In September 2005, Professor Kim Phillip of Columbia University announced the quantum hall effect of graphene at the same time as Professor Andre Geim. In 2007, two groups worked together to study the quantum hole effect of graphene at room temperature and published thesis. Professor Geim and Professor Novoselov were awarded the Nobel Prize in Physics for their groundbreaking contribution to the discovery of a two-dimensional material graphene in 2010.
Special Features of Graphene
200 times mechanically stronger than steel
Tensile Force: ~130 GPa, Strength: ~1.1 TPa
100 times more electrical conductive than copper
Resistance: 10 ohm/cm, Electrophoretogram: 40.000 cm .v-1 .s-1
Twice more heat conductive and absorptive than diamond
5300 W.m-1.K-1
Clean as much as the environment where bacteria cannot increase
99.9% bacterial multiplication
Thin as one atomic layer(0.35nm)
1nm = 1/𝐵𝑖𝑙𝑙𝑖𝑜𝑛 m
Ultra lightweight as much as one eyelash weight of a cat
0.77 mg/m
Transparent as much as single graphene layer can transmit 97% of light
