Chirality-Dependent Growth Rate of Carbon Nanotubes - A Theoretical Study

We consider geometric constraints for the addition of carbon atoms to the rim of a growing nanotube. The growth of a tube proceeds through the conversion of dangling bonds from armchair to zigzag and vice versa. We find that the growth rate depends on the rim structure (chirality), the energy barriers for dangling bond conversion, and the growth temperature. A calculated chirality distribution derived from this minimalistic theory shows surprisingly good agreement with experiment. Our ideas imply that the chirality distribution of carbon nanotubes can be influenced by external parameters.