Comparison study of semi-crystalline and highly crystalline multiwalled carbon nanotubes

Very different types of straight and long multiwalled carbon nanotubes, ran ging from semi-crystalline to highly crystalline, are obtained using a floa ting reactant method, by merely changing the flow rate of the carrier gas. Graphitization behaviors of these nanotubes are studied comparatively in te rms of their microstructure and morphology, showing a large change in struc ture for the semi-crystalline nanotubes, but little change in the highly cr ystalline nanotubes with heat treatment. (C) 2001 American Institute of Phy sics.