Stability of dispersions in non-aqueous media. Part 8.—Theoretical analysis of heterocoagulation

Abstract

The potential energy of charged colloidal particles in media of low dielectric constant has been derived by application of Maxwell's equations for the potential energy of charged conducting spheres. In this treatment the presence of an electric double layer is ignored. Data computed using the Maxwell expressions are compared with those obtained from the simple Coulombic law for repulsion between point charge. The differences are particularly significant for small particle separations. Serious errors are introduced by the use of Coulomb's law for particles interacting at constant potential, but for the constant charge case are significantly less although usually > 5 %.