HETEROCOAGULATION BETWEEN SMALL AND LARGE COLLOIDAL PARTICLES .1. EQUILIBRIUM ASPECTS

Heterocoagulation between small positive (Fe2O3, silica, polystyrene) and large negative polystyrene particles was experimentally studied by a counting technique. The formation and the structure of the resulting heteroparticles were particularly investigated. This study led to the conclusion that, when dealing with mixtures of oppositively charged hydrosols, which are individually stable, the size ratio and the relative number of the interacting units are the only parameters which govern the structure of the resulting heteroparticles. The chemical nature of the partner does not play any role except in determining the pH range at which each one bears the required opposite electrical charge. © 1990.