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Graphene

July 2, 2011 at 5:31 am
filed under Computing, Electronics, General, Nanotechnology

Carbon is the sixth element on the periodic table.  It’s nucleus contains six protons.  The three isotopes are C₁₂, C₁₃, and C₁₄, with nuclei containing six, seven, and eight neutrons
respectively.  It’s electron rings contain six electrons, two in the inner ring and four in the outer ring.

Carbon is an amazingly versatile chemical substance.  Over ten million organic compounds, those based on carbon, have been described.  All life on earth is based on carbon.  Hydrocarbons, proteins, fats and fatty acids, and nucleic acids – the
chemicals of life – are all based on carbon.

Carbon has two commonly occurring crystalline forms, diamond and graphite.  Graphite is by far the more common.  Graphite is a conductor of electricity and can be used as a lubricant.  It is so soft that it can be used to make marks on paper – it’s name
comes from the Latin word for writing.  Pencil lead is actually made of graphite mixed with a clay binder.

It turns out that the actual crystal of graphite is graphene.  Graphite itself is a very large pile or stack of these graphene crystals.  Each graphene crystal is a two-dimensional sheet of carbon atoms, two-dimensional in that it is only one atom thick.  Each carbon atom is connected to three other carbon atoms at angles of 120 degrees.  The sheet can be isualized as a sheet of chicken wire at the atomic level with rings of six carbon atoms connected by their bonds.

It was only in 2004 that individual graphene crystals were isolated.  This feat, recognized with the 2010 Nobel Prize in Physics, allowed the first studies of the properties of individual graphene crystals.  These studies in turn led to an explosion of interest in graphene which continues to this day.  Graphene has properties that make it unique.  It is the first two-dimensional substance ever found.  It is the thinnest and strongest material, the best conductor of heat, and a much better conductor of electricity than copper.
It is virtually transparent and it is so dense that no gas, not even helium, can pass through it.  But it is the potential of graphene to replace silicon which makes it a very strong candidate for the sixth paradigm.  We’ll be taking a look at that soon.

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