Abstract
A flame synthesis technique of coiled carbon nanotubes using acetylene jet flames and iron catalyst is presented. It was found that acetylene flames generate single wall coiled nanotubes within in a narrow pyrolysis zone above the burner for a limited range of fuel flow rates. The corresponding local convective time scale corresponding to the coiled nanotube formation zone is around 0.04 ms. The yield of the coiled carbon nanotubes was further increased by changing the local convective time scale with the addition of controlled turbulence.