Two- and one-dimensional flocculation of silica spheres on substrates

Abstract

A new method for assessing polymer adsorption onto a macroscopic surface and the variation of the adsorption density along the surface is proposed. The presence of the adsorbed polymer is inferred from the adherence of colloidal particles to the surface; conditions are selected such that the particles would not bond if the adsorbed polymer were not present. The method is used to monitor increases in polymer adsorption density and to reveal nonuniform distribution of the adsorbed polymer in patterns having a scale larger than the size of the decorating particles. The technique has been demonstrated to study the effect of chemical pretreatments of surfaces on polymer-induced flocculation of silica to glass. Also, interesting one- and two-dimensional decorations have been obtained, possibly as a result of the surface heterogeneity. © 1987 Academic Press, Inc.