Approximate analytic expression for the stability ratio of colloidal dispersions

Abstract

Approximate analytic expressions are derived for the stability ratios of dispersions of spherical colloidal particles with and without viscous interactions between particles on the basis of the DLVO theory of the potential energy of the electrostatic and van der Waals interactions between two approaching particles. The obtained approximate stability expressions agree with exact numerical results with negligible errors and are applicable irrespective of the magnitude of the potential maximum unlike the previous approximate stability expressions, which are applicable only when the potential maximum is much greater than the thermal energy.