Preparation of monodispersed hollow polystyrene microspheres

The monodispersed water in oil in water(W_1/O/W_2) multiple emulsion was prepared by dispersing the water in oil(W_1/O) emulsion obtained by stirring into the continuous phase through the SPG(shirasu porous glass) membrane.Subsequent solvent evaporation was followed and monodidpersed hollow polystryrene(PS) microspheres were successfully prepared.The effect of the mean pore diameter of SPG membrane on the size and size distribution was investigated.Furthermore,the effect of surfactant concentration on the porosity and monodispersity of PS microspheres was discussed.According to the results of particle size analyzer and SEM images,the monodispersed hollow PS microspheres obtained are 2.0～2.4 times of the mean pore size of SPG membrane.