Full atomistic molecular dynamics simulations were used to study the diffusion of alkane molecules in single-wall carbon nanotubes, for various alkane chain-lengths and nanotube diameters. The self-diffusion coefficient, mean-square gyration and bond-orientation order parameter of the alkane molecules and the average intermolecular interaction energy per segment between the nanotube and alkane were calculated. The structure of the alkane in these nanotubes was characterized in terms of the radial distribution function, and the results showed that the self-diffusion coefficient was related to the nanotube diameter. The component of mean-square gyration in the z-direction scaled, with the alkane chain length in the (9,9) nanotube, as N1.07. This was in good agreement with the predictions of scaling theory for polymers. The results showed that the nanotube diameter and the 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. H.Yang, Y.Liu, H.Zhang, Z.S.Li: Polymer, 2006, 47[21], 7607-10