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1.11.2.2._GRAPHITE_AND_GRAPHENE

[ ‘Graphene: Status and Prospects’, A.K. Gelen, Science, Vol 324, 19 th June 2009, 1530-1534;

‘Carbon Woderland’, Andre K. Geim and Philby Kim, Scientific American, April 2008, 90-97]

The two other alltropic forms of Carbon are Graphite and Buckminsterfullerene[Appendix XXXXV]. The crystal structure of these two allotropes are shown in Figure 1.57. The comparative study of these three alltropic forms of carbon is shown in Table 1.22.

In Graphite each layer has hexagonal arrangement of carbon atoms. As seen in Figure 1.57, each carbon atom has three neighbouring carbon atoms covalently bonded. This arrangement leaves 1 electron unbounded hence free to be released through out the lattice. This makes Graphite a good conductor and it has a metallic luster. There is a weak Van der Waals induced bonding between the layers as already discussed in Bonding chapter. Hence layers can move past one another and flak easily. They find applications in lubricants and pencil lead.

Graphite is a 3D bulk material which consists of stacks of 2D one atom hexagonal rings of Carbon sheets. In recent years with the advent of nanotechnology , it has been possible to separate out individual sheets and experiment with it. The flat sheet of hexagonal rings of Carbon is known as GRAPHENE. Wrapped up graphene is known as fullerenes. When it is wrapped up in honey comb cylinder like structure it is called carbon nano-tubes and when it is wrapped as soccer ball shaped as in Figure 1.57 then it is called bucky ball.

This 1 atom thick 2D grapheme is a wonder material. It is the strongest material- stronger than steel. The orderly arrangement of hexagonal rings is repeated through out the sheet with remarkable regularity as a result even at room temperature of 300K electron’s mean free path is in micrometer. This implies very few and far between scattering. Hence under the influence of electric field, electrons behave like mass-less Dirac quasi-particles on which relativistic quantum mechanics or Quantum Electrodynamics applies. Electron travels at (1/300) of speed of light. This is in contrast to electrons in 3D semiconductor where mass is near that in free space and mobility and drift velocity is much lower. These useful properties has opened immense possibilities for grapheme based electronics. Ballistic FETs are emerging which are suitable for 100GHz and above application. Graphene has given a new lease of life to Moore’s Law of microminiaturization. It will enable the scaling down right up to 10 nm.

Under normal conditions graphite crystallizes out but under excessive pressure condition diamond is favoured. Once the diamond has crystallized it remains stable under normal temperature and pressure. Deep in Earth’s vegetation remains are transformed into diamonds and coal over eons. This is the source of natural diamond.

Synthetic diamond can be obtained in the following manner. Graphite is dissolved in molten cobalt or nickel and the mixture is compressed by 60,000 bar pressure at 1600K. Less than 1 mm wide diamonds can be synthesized in this way. It is widely used in industrial applications for cutting and grinding tools.

Questions & Answers

are nano particles real
Missy Reply
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
Lohitha
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
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Source:  OpenStax, Solid state physics and devices-the harbinger of third wave of civilization. OpenStax CNX. Sep 15, 2014 Download for free at http://legacy.cnx.org/content/col11170/1.89
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