Theoretical bounds for multiwalled carbon nanotube growth

The role of the lip–lip interaction on the non-catalytic growth of multiwalled carbon nanotube is explored with classical molecular dynamics simulations. The simulations show that the lip–lip interaction actually provides a natural mechanism for the closing of the different nanotube shells, irrespective of the number of shells making up the nanotube. Based on an extensive annealing study, we estimate the mean time to closure and an upper bound length for nanotubes that can be formed, as a function of nanotube diameter and temperature. The extrapolated results are in good agreement with the existing experimental data.