Disjoining Pressure in Thin Spherical Liquid Films and Vapor Layers with Molecular Correlations Included

Abstract

Disjoining pressures in thin liquid films around nanosized wettable spherical particles and in thin vapor layers around non-wettable particles were calculated as functions of the lyophility degree, film thickness, and particle size on the basis of the expression for the grand thermodynamic potential as a molecular density functional. A characteristic feature of this approach is the full consideration of hard-sphere molecular correlations using the fundamental measure theory in the density functional theory (DFT) and calculation of the complete dependence of the grand thermodynamic potential of the system on the stable droplet or bubble size. Although the newly calculated dependences of the disjoining pressure are in a qualitative agreement with those found using a simpler gradient version of the molecular density functional, the results of the two methods considerably differ quantitatively. It was confirmed that the disjoining pressure in a liquid film around a nanosized lyophilic particle increases with increasing particle size and lyophilicity.