Flocculation of polymer latex dispersion induced by a polyelectrolyte

Abstract

The stability of high surface charge latex dispersions containing non-adsorbing polyelectrolyte was investigated. Poly-(styrene/sodium p-vinylphenylsulphonate) copolymer latices and sodium polystyrenesulphonate systems were used. Flocculation was confirmed using three observational methods — transmission measurement, microscopy and dynamic laser light scattering particle analysis. It was found that in flocculation the cluster size of the flocculated particles split into two peaks — a small peak consisting almost entirely of single particles and a larger peak which increased with time. Moreover, the floc which formed was in an ordered state and changed into a crystalline phase after sedimentation.