Preparation of Size Controllable Monodispersed Polystyrene Microspheres by Dispersion Polymerization

Polystyrene microspheres were prepared by dispersion polymerization of styrene in the medium of ethanol and water,using azodiisobutyronitrile(AIBN) and poly(vinylpyrrolidone)(PVP) as the initiator and stabilizer,respectively.The effects of the reaction parameters,such as the monomer concentration in the systems,the initiator dosage,the stabilizer dosage and the ratio of ethanol and water,on the particle size and the size distribution were investigated.Polystyrene microspheres were observed by transmission electron microscopy(TEM),field emission scanning electron microscopy(FE-SEM),Fourier transform infrared(FTIR) spectroscopy,dynamic light scattering(DLS),etc.It is shown that experimental parameters are in conformity with the mechanism of forming microspheres,the average size of as-prepared microspheres ranges from 200 to 1000 nm.The conclusions also show that only specific sets of conditions may produce particles with a narrow distributed size distribution.