Encapsulation of nano-silica particles by polystyrene with dispersion polymerization

In this paper, the polystyrene/nano-silica composite particles were prepared and characterized according to the following steps. First, the nano-silica particles were pretreated with the surfactants under ultrasonic field. Secondly, the dispersion polymerization of styrene in a water-ethanol medium, with poly(N-vinyl pyrrolidone) (PVP) as stabilizer and 2, 2-azobisizobutyronitrile (AIBN) as initiator in the presence of nano-silica particles was initiated through ultrasonic irradiation by taking its advantages of multieffect, i.e., dispersion, crushing, activation, and initiation. Finally, the encapsulation of composite particles were investigated with SEM, TEM, FTIR and X-ray photoelectron spectroscopy (XPS).