Full atomistic molecular dynamics simulations were used to study the diffusion of alkane molecules in single-wall carbon nanotubes, with various alkane chain lengths and nanotube diameters. The self-diffusion coefficient, mean-square gyration and bond-orientation order parameter of alkane molecules and the average intermolecular interaction energy per segment between single-wall carbon nanotubes and alkanes were calculated. Furthermore, structure of alkane in single-wall carbon nanotube was characterized through the radial distribution function, with results showing that the self-diffusion coefficient was related to the nanotube diameter. The component of mean-square gyration in z-direction scales with alkane chain length in single-wall carbon nanotube (9,9) as N1.07, which was in good agreement with the prediction from scaling theory for polymers. The obtained results showed that nanotube diameter and alkane chain length were important factors affecting the behavior of one-dimensional confined alkanes.

Diffusion of Single Alkane Molecule in Carbon Nanotube Studied by Molecular Dynamics Simulation. Yang, H., Liu, Y., Zhang, H., Li, Z.S.: Polymer, 2006, 47[21], 7607-10