Morphological varieties of Carbon Nanotubes

27 February 2007

Carbon nanotubes display electronic, mechanical, chemical or optical properties that can be used in different applications such as molecular electronics, nanomechanical devices, sensoring, energy storage and therefore scientists from all other fields also find interest in carbon nanotubes. In actual the application of carbon nanotube is generally depend on chemistry, which further depends on the nanotube synthesis, purification or modification processes.

We can modify nanotubes according to the required application, The different methods generally used for modification includes partial oxidation and opening of nanotubes, attaching functional group to the open ends of nanotubes, attaching functional groups to the side walls of the nanotubes, replacing carbon atom of the nanotubes by other chemical elements or groups, filling the cavities in nanotubes with different substances, absorption of gas and inserting other atom or molecule into the intertubular space.

So far dozens of morphological varieties of carbon nanotubes has already been discovered and these morphological varieties differ in nanotube diameter, surface structure, defect densities and aspect ratio. Some of the multiwall nanotubes and nanofibres have internal cross connections. These interconnections are formed by curved graphemes. Moderate cross connection can contribute to a bamboo like structure while a relatively high cross connections may cause conical structures.

Single wall nanotubes, multi wall nanotubes and nanofibres can form secondary structure and the common secondary structure form a single wall nanotube is bundle or rope that is a 2-D triangular lattice with a lattice constant of 1.7. Secondary structure in multi wall nanotube is generally diverse. Although bundle like structure is less common in multi wall nanotubes, a new octopus like structure has recently been synthesized. So a number of morphological varieties have been synthesized and a lot of study has been carried out on single wall nanotube, multi wall nanotube and single wall nanotube bundles.

Related Posts: