To prepare relatively large negatively charged polymer particles in a size range from 0.3 mu m to 0.5 mu m, having high surface charge densities, the heteroaggregation of small (50100 nm), highly charged (185 and 421 mu eq/g) anionic polystyrene particles onto the surface of larger (317466 nm) poly(vinylbenzyl choride)-based cationic (10, 614, and 830 mu eq/g) particles was carried out. As a result, particles with different surface charges, having a core-shell structure, were successfully prepared. First, aggregated particles were formed via heteroaggregation of the lowest surface charge density anionic particles (185 mu eq/g) with the lowest surface charge density cationic particles (10 mu eq/g). However, the anionic particles in the shell layer desorbed with time owing to the relatively weak interaction between the two particles. Second, aggregated particles comprised of the highest surface charge density cationic (830 mu eq/g) and anionic latex particles (421 mu eq/g) were formed. However, to prepare a stable system, an excess of the small anionic particles was required, leaving a large number of small particles present in the aqueous phase, which proved difficult to remove. Finally, aggregated particles were formed by heteroaggregation of cationic particles with an intermediate surface charge density (614 mu eq/g) with the highest surface charge anionic particles (421 mu eq/g). As a result, not only were core-shell particles formed, but few free small anionic particles remained in the aqueous phase. In this article, the preparation and characterization of each of these aggregates are discussed in terms of particle size, morphology, and extent of incorporation of the functional groups. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013