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Carbon and Carbon Nanotubes

Carbon is all around us and in us.  It is in DNA, proteins, fats, and carbohydrates.  It makes up approximately 20% of the human body.  It symbolizes love and commitment in some cultures.  It is scratched on paper to express ideas.  It is a key ingredient in the fossil fuels used to power our cities and vehicles.  Not surprisingly, carbon is also a key ingredient in the emerging field of nanotechnology.  Aside from the naturally occurring forms of carbon, graphite and diamond, carbon is also found in the nanostructured forms of fullerenes (or buckyballs) and carbon nanotubes (CNTs).
Diamond
In diamond, each carbon atom is bonded to four other carbon atoms. (A bond is the sharing of electrons between two atoms; we represent a bond by drawing a line between the atoms.) This creates a three dimensional network of bonds. The extended network of bonding is where diamond gets its strength.
Graphite
In graphite, the carbon atoms are only bonded in two dimensions. The carbon atoms form layered sheets of hexagons. Since there are no bonds between the layers, the layers can easily slip off one another. This is why graphite is a good material for pencils - layers come off and get left on the paper as you write.
Fullerenes
In 1996 Richard Smalley, Robert Curl, and Harold Kroto were awarded the Nobel Prize in chemistry for discovering a new form of carbon - the buckminster fullerene, or buckyball. A buckyball looks like a nanometer-sized soccer ball made from 60 carbon atoms. It was named after Buckminster Fuller, an architect who created geodesic dome structures, like the one in the middle of Disney's Epcot Center.
Carbon Nanotubes
The structure of a carbon nanotube is like a sheet of graphite rolled up into a tube. Depending on the direction of hexagons, nanotubes can be classified as either zigzag, armchair or chiral. Different types of nanotubes have different properties. When scientists make nanotubes, they tend to get a mixture of several types. A major challenge in nanoscience today is finding a way to make just one type of nanotube.
(a) armchair, (b) zigzag, (c) chiral

Diamond, Graphite, C60 images from en.wikipedia.org

Nanotube image from theor.jinr.ru

FIND OUT MORE !

CNT Activity 1

CNT Activity 2

CNT Movies

   

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