Direct preparation of monodisperse core-shell microspheres with surface antibacterial property by using bicationic viologen surfmer

By exploringly introducing a bicationic viologen, N-hexyl-Nʹ-(4-vinylbenzyl)-4,4′-bipyridinium bromide chloride (HVV) to dispersion polymerization of styrene (St) in a mixture of methanol and water, we achieved the following results: (1) monodisperse, core-shell microspheres with antibacterial surface were prepared by a simple one-step procedure, (2) diameter, core radii and shell thickness of resultant particles could be controlled by concentrations of HVV, monomer and initiator, and composition of media, (3) HVV could act not only as a monomer as that in previous modifications, but also as an efficient, novel stabilizer, and its copolymerization with St at interfacial layer and coagglutination of (co-)oligomers on core surface due to its moderate reactivity and hydrophilicity were conceived to be main reasons for formation of core-shell structures. Effects of HVV on polymerization behavior of St, evolution of core-shell structure, and morphology, size of particles were investigated. Moreover, antibacterial activity of resulted microspheres against Staphylococcus aureus was assayed.