Physical adsorption on small spherical particles and spherical pores

Abstract

The formal expression for the attractive part of the van der Waals interaction between an atom and the surface of a solid sphere or a spherical cavity is determined. The atom is represented by its dynamic polarizability and the solid by a frequency‐dependent dielectric function. Aside from the geometrical effect of the surface curvature, one takes account of a size dependence of the dielectric function. Quantitative evaluation for argon atoms physisorbed on silver spheres shows that the dispersion energy is reduced with respect to the flat surface, whereas it is enhanced in the case of a cavity.