A perturbational, RAM-like approach for adsorption of non-spherical molecules on solid surfaces

Abstract

A RAM-type perturbational theory of non-uniform fluids of non-spherical molecules in contact with a solid surface has been developed. Several approximate versions of the theory have been considered by assuming that the reference-state properties can be calculated within the Percus–Yevick and the hypernetted chain approximations. Explicit results for nitrogen adsorbed on graphite are presented and compared with the results of grand ensemble Monte Carlo simulations. Additionally, a comparison of RAM-type perturbational theory with other currently used approaches (e.g. ISM theory) has been made. It has been shown that the present approach, though very approximate, leads to a qualitatively correct description of the properties of the adsorption system.