Carbon Nanotubes
Strength:
Hardness:
Electrical:
Carbon nanotubes are the strongest, flexible and stiffest materials of those discovered in terms of tensile strength and elastic modulus.
The hardness (152 Gpa) and bulk modulus (462~546 Gpa) of carbon nanotubes are greater than diamond, which is considered the hardest material.
Because of the symmetry and unique electronic structure of graphene, carbon nanotubes have a very high current carrying capacity.
Properties of Carbon Nanotubes
Multi-walled carbon nanotubes are multiple concentric nanotubes precisely nested within one another, the inner nanotube core may slide, almost without friction, within its outer nanotube shell, thus creating an atomically perfect linear or rotational bearing.
Kinetic:
Optical:
Optical absorption, photoluminescence and Raman spectroscopies of Carbon Nanotubes allow quick and reliable characterization of this "nanotube quality" in terms of non-tubular carbon content, structure (chirality) of the produced nanotubes, and structural defects.
Thermal:
Carbon nanotubes are good thermal conductors along the tube, exhibiting a property known as "ballistic conduction", but good insulators laterally to the tube axis.
A carbon nanotube is a hollow, tube-shaped material, made of carbon, that has a diameter measuring on the nanometer scale. A nanometer is one-billionth of a meter, or about one ten-thousandth of the thickness of a human hair. The graphite layer of the carbon nanotube appears somewhat like a rolled-up chicken wire, with a continuous unbroken hexagonal mesh and carbon molecules at the apexes of the hexagons.
Carbon nanotubes were first discovered by two Russian scientists in 1950s. However, it was not widely reported until its discovery by scientist Lijima in 1991 when he studying the synthesis of fullerenes by using the electric arc discharge technique. Since then, it brought carbon nanotubes into the awareness of the scientific community as a whole.
Carbon nanotubes have many structures, differing in length, thickness, and in the type of helicity and number of layers. Although they are formed from essentially the same graphite sheet, their electrical characteristics differ depending on these variations, acting either as metals or as semiconductors. Their name is derived from their long, hollow structure and the walls formed by one-atom thick sheets of carbon, called graphene.
What are Carbon Nanotubes?[citeration 18,]
