TEM studies of conical scroll carbon nanotubes formed by aerosol synthesis

Abstract

Conical carbon nanotubes were obtained by the method of gas-phase chemical decomposition of a carbon precursor on the surface of a catalytic particle suspended in a carrier gas stream (also known as “aerosol method”). TEM study at the JEM-2010 microscope showed that the observed angles at the vertex of the cones (apex angles) were predominantly 5°, 10°, 15° and 20° regardless of the presence of a catalyst particle inside the cone. The analysis of the apex angles witnesses that the nanotubes have a scroll type of structure. Two alternative explanations are proposed for the formation of an unconventional apex angle 5°. The peculiarities of destruction of the catalyst particles inside the nanotubes are revealed.