Carbon Nanotubes Essay

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* A nanotube is a nanometer (Gr. nanos, “dwarf” + Gr. metron, “unit of measurement”) scale tube-like structure. It combines the SI prefix nano with the parent unit name metre, and is equal to one billionth of a meter, or 1.0 x 10-9 in scientific notation. * Carbon nanotubes (CNTs), one of the many forms of nanotubes, are tube-shaped molecules made of carbon-carbon bonded [allotropes (property of some chemical elements to exist in two or more different forms) of carbon] atoms. The carbon atoms are linked in hexagonal shapes and are bonded covalently (sharing electron pairs between atoms) to three other carbon atoms. Carbon nanotubes are one to ten nanometers in diameter (for comparison, 50,000 times thinner than that of a human strand of hair) and can be up to several centimeters in length. Although they are incredibly strong, they are brittle. This means that they can be bent, and when released, they will spring back to their original figure. * CNTs are chemically related, by the definition of an allotrope of carbon, to the lead of a pencil, graphite, diamond, and more. To visualize this structure we can use graphite as an example. Graphite is a flat sheet of carbon atoms in the form of molecular wires and one of these sheets rolled into a cylinder is the basic structure of a carbon nanotube. This hallow molecular wire is extremely conductive as all of the atoms are on the surface and when something else interacts with the surface it could have a dramatic effect on the flow of molecules through the nanotubes. * One type of carbon nanotube has a cylindrical shape with open ends. Another type of nanotube has closed ends, formed by some of the carbon atoms combining into pentagons on the end of the nanotube. The wires, or sheets of carbon, do not need to be rolled up lengthwise. You can do it at an angle, make the tube diameter larger, or smaller, put
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