Mechanism of thermokinetical selection between carbon nanotube and fullerene-like nanoparticle formation

Abstract
Open edge stability of carbon nanotube growth is suggested to depend on kinetically defined competition between pentagon and hexagon formation. Nanotube growth is possible when the time of hexagon formation, determined by the surface diffusion flux to the growth edge (proportional to carbon vapor pressure), is much lower than that of pentagon formation, which depends on the temperature. The competition of pentagon/hexagon formation at the growth edge together with thermal effects of condensation heat release and heat dissipation by radiation and collisions with inert gas (He), is shown to define selection between nanotube nucleus evolution into (i) continuous nanotube growth or (ii) fullerene- or cage-like nanoparticle formation. The involvement of catalyst nanoparticles enhances the formation of nanotubes by enhancing growth edge stability against pentagon formation under pressure-temperature conditions at which the open edge would otherwise become unstable closing nucleus into the fullerene-like nanoparticle.

This publication has 30 references indexed in Scilit: