Abstract: Helical carbon nanotubes were synthesized by a chemical vapour deposition method from both silica aerogels and silica xerogels containing catalysts.
The research result shows that the helical carbon nanotubes prepared from the silica aerogels have the following pecularities compared with those from
silica xerogels: (1) more degree of graphitization; (2) smaller diameter; (3) better helical shape, namely, the more identical pitch. The peculiar
mesoscopic properties of aerogels are responsible for those above pecularties of helical carbon nanotubes prepared from silica aerogels when compared
with those from xerogels. What’s more, the anisotropy of catalytic activity of the catalyst particles leads to the growth of helical carbon nanotubes.

Key words: chemical vapour deposition, helical carbon nantotube, aerogel