Heterocoagulation. Part 3.—Interactions of polyvinyl chloride latex with Ludox Hs silica

Abstract

The stability of a mixed colloidal dispersion consisting of monodispersed PVC latex and Ludox HS silica particles in the presence of counterions of 1+, 2+ and 3+ charge has been studied by light scattering, electrokinetic and adsorption techniques. It was found that either (1), selective coagulation of Ludox HS in the presence of PVC latex or (2), stabilization of latex by silica against electrolytic coagulation, can occur depending upon the experimental conditions. The deposition of silica onto latex follows a Freundlich-type adsorption isotherm. The theory of heterocoagulation is used to explain the various phenomena observed.