Single Stage Polymerization Technique for Producing Micron-Sized, Highly Monodisperse Polystyrene Particles in Aqueous Media.

Synthesis of polystyrene/silica composite particles by soap-free emulsion polymerization using positively charged colloidal silica

“…Thus, the addition of oppositely charged surfactants controls the aggregation behavior to produce micrometer-sized polymer particles [27,28]. For example, Konno and co-workers [29,30] synthesized fairly monodisperse polystyrene microspheres by adding a cationic surfactant, cetyltrimethylammonium bromide (CTAB), in the soap-free emulsion polymerization initiated by an anionic initiator, KPS. They added CTAB 0.5-3.0 min after the initiation.…”

“…The particle size was marginally influenced by the CTAB addition time and the particle size distribution became broader in the presence of CTAB, since the agglomeration took place for a longer period of time. This principle was extended to the use of an amphoteric surfactant, dimethyldodecylbetaine, which possesses both cationic and anionic moieties [30,31].…”

Soap-free synthesis for producing highly monodisperse, micrometer-sized polystyrene particles up to 6 μm

“…To meet the demand of reducing impurity and the use of harmless solvents, the authors performed a series of experiments based on soap-free emulsion polymerization [19][20][21][22][23][24] and recently proposed a novel method that employed an amphoteric initiator, 2,2 -azobis [N - (2- methylpropionamidine] hydrate, under pH control with a buffer system of NH 4 OH/NH 4 Cl. Polymer particles formed in the polymerization have ionizable groups arising from the amphoteric initiator.…”