Hetero-coagulation of polymeric core-corona microspheres

Hetero-coagulation between polystyrene core-poly(vinylamine) (PVAmMS) and poly(methacrylic acid) corona microspheres in an aqueous phase was studied by quantitative analysis of precipitated microspheres, absorbance change of mixed dispersions using UV-Vis spectroscopy, transmittance electron microscopy (TEM) observation, hydrodynamic particle size measurement, and ξ-potential analysis. It was found that a 12-h incubation was enough for the formation of hetero-coagulation. The microspheres were electrostatically aggregated to each other. Uniform hetero-coagulated assemblies, which were stably dispersed in an aqueous phase, were obtained with larger size and larger mixture ratios of microspheres (PMAAMS/PVAmMS).