The influence of flexible walls upon the self-diffusion of CH4 in an isolated single-walled carbon nanotube was studied using molecular dynamics simulations. By simulating the carbon nanotube as a flexible framework, it was demonstrated that the flexibility had a crucial influence upon self-diffusion at low loadings. This influence could be incorporated into simulations of a rigid nanotube by using a Lowe-Andersen thermostat which was based upon interface-fluid collisions. The reproduction of the results of a flexible carbon nanotube, using a rigid nanotube simulation, was excellent.

Understanding the Loading Dependence of Self-Diffusion in Carbon Nanotubes. S.Jakobtorweihen, M.G.Verbeek, C.P.Lowe, F.J.Keil, B.Smit: Physical Review Letters, 2005, 95[4], 044501