Carbon nanostructures in silica aerogel composites

A new method of preparing carbon nanotubes and their derivatives using silica aerogels as a matrix for the deposition of carbon is repeated. We present results of observations of graphite tubes and rings including nested structures in nanometer dimensions using high resolution transmission electron microscopy. Furthermore, we propose a model for the growth of carbon nanotubes in three steps including nucleation, growth, and closure of tubes.