Interactions between physically adsorbed molecules

Abstract

A two-dimensional second virial coefficient B^* is computed using an adatom-adatom interaction energy which is derived from the theoretical work of McLachlan. At present, an analysis of the available experimental data for the physical adsorption of Ar on P33 (2700°C) cannot distinguish between the interaction energy derived from McLachlan's work and one derived from the theory of Sinanoĝlu and Pitzer. The analysis does, however, yield an “experimental” estimate for one of the integrals in McLachlan's theory which determines the long-range adatom-adatom-surface interaction energy. The “experimental” value for this integral agrees well with an approximate theoretical evaluation.