Study of growth of carbon nonotubes on pure metal and metal alloy electrodes

Cathode erosion under the action of an electric arc is a major problem in plasma torches. The reduction of cathode erosion through the development of superior cathode materials would result in more economical operation of plasma torches. Carbon nanotubes have favorable electron emission properties; they are studied here for the fabrication of superior cathode materials.In this work, the growth of carbon nanotubes (CNT) using thermal CVD is studied on different metal and metal alloy electrodes. Electroless Ni coated on Monel substrates and Ni deposited Si wafer substrates with 20 nm Cr under layer gave the highest density of CNT growth. Variations of the CNT coverage density was observed when varying the surface roughness on pure Ni and Monel with various degree of polishing prior to the CNT growth. Cupro-Nickel alloys and electroless Ni plated Cu did not show to be favorable for the growth of CNT. Tests on the growth of CNT in a PECVD reactor were not successful; the transport of the carbon precursor to the electrodes still needs further study. Other applications such as the use of the CNT layer as a nanoparticle filter and collector, the formation of a CNT-nanoparticle composite film, the growth of a 3D structure of a multi-branched CNT, and the growth of CNT on alloy meshes were also studied and discussed in this thesis