Carbon nanotubes for integration into nanocomposite materials

We have synthesised carbon nanotubes by thermal chemical vapour deposition using C₂H₂/N₂. Multiwalled carbon nanotubes (MWNTs) have been produced uniformly with high yield on Si substrates using thin nickel layers as catalyst material. It is observed that surface modification of the Ni by annealing in N₂ and etching in an HF solution prior to the reaction of C₂H₂ gas are crucial steps for MWNTs growth. This pretreatment, coupled with growth temperature, can be used to control the diameters of the carbon nanotubes grown. We have used such MWNTs as reinforcements within a polymer matrix to produce a composite material with improved properties.