Wetting and structure of a fluid in a spherical cavity.

Abstract

The equilibrium local densities, structure, and wetting of a one-component fluid in a spherical cavity, of variable radius R, are determined, using density-functional theory, as functions of two parameters characterizing the system: the radius R and the cavity/fluid potential parameter epsilon(W). The cavity acts as an external potential V(ext)(r) on the molecules of the confined fluid, the particles of which are of constant diameter d. The equilibrium density profile, as a result of strong confinement, develops peaks in the center of the cavity and/or close to the pore wall and, in certain situations, in other intermediate points; the cavity can also be liquid full, capillary condensation.