Carbon nanotubes are ultra-thin fibres of carbon and a nanotechnologist’s dream.Carbon nanotubes, long, thin cylinders of carbon, were discovered in 1991 by S. Iijima.Carbon nanotube (CNT) are allotropes of carbon with a cylindrical nanostructure, configurationally equivalent to two dimensional graphene sheet rolled into a tube.They are made from thin sheets of carbon only one atom thick – known as graphene – rolled into a tube only a few nanometres across. Even the thickest is more than a thousand times thinner than a human hair.
Interest in carbon nanotubes blossomed in the 1990s when they were found to possess impressive characteristics that make them very attractive raw materials for nanotechnology of all kinds.They have unique properties.They are about 1000 times stronger than steel and very good thermal conductors and good electrical conductors.CNT exhibits extraordinary mechanical properties: the Young's modulus is over 1 Tera Pascal. It is stiff as diamond. The estimated tensile strength is 200 Giga Pascal. These properties are ideal for reinforced composites, nanoelectromechanical systems (NEMS).