Molecular dynamics of SF6 in porous silica

Abstract

Molecular dynamics of SF₆ in small cylindrical pores in amorphous silica is studied by computer simulations. The solid is represented by an atomic model that takes into account microscopic structure of the surface. Adsorbent is modeled as an assembly of six Lennard‐Jones potentials. Rotational and translational correlation functions are calculated and discussed in terms of temperature, density, pore diameter, and surface potential. Changes in the motion along the pore axis and pore radius are analyzed. It is shown that surface interactions determine translational and rotational diffusion of molecules in the monolayer, but at distances greater than two molecular diameters, the dynamics can be compared to that in the bulk liquid.