The synthesis of megatubes: New dimensions in carbon materials

Extremely large carbon tubes, some exceeding 5 mum in diameter, were produc ed with both laser and electric are techniques using graphite, a transition metal catalyst, and a reactive third-body gas. We have named these structu res carbon megatubes. They are the first carbonaceous tubes large enough to observe using optical microscopy. We also report the synthesis of what we believe to be the first self-assembled branched nanotubes. In addition to t heir extreme diameters and unique morphologies, X-ray photoelectron spectro scopy has shown that these tubes also contain a significant amount of nitro gen atom incorporation into the graphite lattice. Subsequently, these nitro gen functionalities were shown to interact with rhenium pentacarbonyl bromi de and serve as anchor points to tether molecules to the surface of the tub ules.