Heterocoagulation of amphoteric latex colloids

Abstract

Amphoteric latex colloids with permanently bound carboxyl and amine groups have been used to test the general theory of heterocoagulation. By varying the carboxyl-to-amine ratio, particles with isoelectric points between pH 5 and 8 were prepared and turbidimetric methods used to monitor both homo- and heterocoagulation behaviour. Close agreement between theory and experiment was observed, particularly in the case where the ratio of particle numbers was varied. Heterocoagulation between an amphoteric latex and a conventional latex was examined and evidence of regulation-type behaviour was obtained.