A self-diffusion model of Lennard-Jones fluid in confined space was developed by using equilibrium molecular dynamics simulation method. The radial distribution function was utilized to analyze the Lennard-Jones fluid microstructure. The self-diffusion coefficient of Lennard-Jones fluid in the nanoscale confined space was calculated and compared with that in free space. The effects of temperature, density, and confined scale on the self-diffusion coefficient were all investigated at the molecular level. The results indicated that the Lennard-Jones fluid self-diffusion coefficient in confined space increased with the increasing confined scale. Similar to that in free space, the Lennard-Jones fluid self-diffusion coefficient in confined space also increased approximately in a linear fashion with temperature, while it decreased gradually with the increasing density. However, the Lennard-Jones fluid self-diffusion coefficient in confined space was smaller than that in free space with the same temperature and density. In addition, the accuracy of the self-diffusion coefficient calculated by the present model was verified by the experimental data available in the literature.

Molecular Dynamics Simulation of Self-Diffusion Coefficient of Confined Lennard-Jones Fluid. Yang, L., Chen, Y., Zhang, C., Shi, M.: Journal of Southeast University - Natural Science, 2011, 41[2], 317-20