Multi walled carbon nanotubes (MWNTs, CNTs) were prepared by chemical vapor deposition (CVD). In chemical vapor deposition (CVD), a volatile precursor undergoes thermal decomposition at elevated temperatures to form a solid deposit on a substrate. 1 The diameter of the tube ranges between 110-170nm and the length is between 5-9μm. The multiwalled nanotubes are stable in inert atmosphere upto a temperature of 3697^oC.

Carbon nanotube, multi-walled (MWNT) belongs to the class of carbonaceous materials with excellent physiochemical, thermo-mechanical and electrochemical properties. This material can be used in a variety of sustainable energy applications such as solar cells, photocatalysis, biosensor, gas sensor, supercapacitor and as a filler that acts as a reinforcement to improve the mechanical property of composites.

Toxic and immunological effects of carbon nanotubes on human colorectal cancer cell line (Caco-2), the human breast adenocarcinoma cell line(MCF-7), Calu-3 cells from human lung adenocarcinoma and serous cells of proximal bronchial airways was investigated. These multiwalled carbon nanotubes were used to design a 3D, free standing porous carbon structure. The self-supporting structures could find potential uses in energy storage, supercapacitors, photovoltaic cells, field emission devices, sensors and high performance catalysts.Polystyrene/MWNTs nanocomposites have been fabricated and studied for its electrical and optical properties. Preparation of platinum/MWNTs/cobaltite nanocomposites has also been reported.

Chemical Vapor Deposition (CVD) Method