Synthesis of Single-Walled Carbon Nanotubes in a Premixed Acetylene/Oxygen/Argon Flame

摘要

Single-walled carbon nanotubes have been observed in the post-flame region of a premixed acetylene/oxygen/argonrnflame operated at 50 Torr. Iron pentacarbonyl vapor was used as a source of the metallic catalyst which is necessary forrnnanotube growth. A thermophoretic sampling method and transmission electron microscopy were used to characterizernthe solid material present at various heights above burner, giving resolution of formation dynamics within the post-flamernregion. Catalyst particle formation and growth dominates the immediate post-flame zone, followed by inception ofrnnanotubes beginning at around 30 ms and finally coalescence of nanotubes to form tangled clusters late in the post-flamernregion. Once initiated, nanotube growth is rapid, on the order of 10 μm per second.