Synthesis of short multi-walled carbon nanotubes by molecular self-assembly

Short multiwall carbon nanotubes (MWCNTs) were synthesized by pyrolysis of a polysilazane-polyvinyl pyrrolidone mixture that was characterized by dynamic light scattering. It was found that the polymer mixture had a tube-shaped aggregate at the nanometer scale. The MWCNTs are −30 nm in diameter and −500 nm in length. Structural characterization revealed that they have a well-developed tubular structure with a uniform wall thickness, but are not well graphitized. The formation of the MWCNTs can be accounted for by the self-assembly of polyvinyl pyrrolidone in the solution to form polymeric nanotubes that were converted to MWCNTs by subsequent pyrolysis.