A Molecular Dynamics Simulation Study of the Density and Temperature Dependence of Self-diffusion in a “Sphere-cylinder” Micropore

Abstract

We report Molecular Dynamics calculations of density profiles and self-diffusion coefficients of Lennard-Jones fluids confined in a pore of “sphere-cylinder” geometry consisting of spheres interconnected through cylindrical sections. The geometrical characteristics were the radius of the cylinder R = 2σ, the ratio of the radius of the cylinder to radius of the sphere R/R_s = 0.85 and the ratio of length of cylinder to length of sphere L/A = 1.5. The results were compared with previous results on a cylindrical pore of the same radius as that of the cylindrical section of this model and it was found that the self-diffusion coefficients parallel to the pore walls were generally lower although their relative difference was within statistical errors.

Key Words:

• sphere-cylinder geometry
• molecular dynamics
• diffusion coefficients