Theory of films. - I. Single dielectric films

Abstract

The van der Waals free energy of a system of two half-spaces of aqueous electrolyte separated by a dielectric layer is studied. The coupling of the van der Waals free energy to the structure of the electrical double layers in the system is calculated in two cases: (i) fixed surface charge density; (ii) fluctuating surface charge density due to the ionization of long chain carboxylic acid groups adsorbed on to the surfaces of the dielectric layer.