Aqueous core polystyrene microspheres fabricated via suspension polymerization basing on a multiple pickering emulsion

ABSTRACT Multi‐hollow or hollow polymer particles are of great interest in many fields. Here we successfully fabricate polystyrene microspheres with aqueous cores through w/o/w Pickering emulsion stabilized by modified SiO2 nanoparticles. The final structure and constituents of the microspheres is investigated via SEM, X‐ray photoelectron spectra, and thermo‐gravimetric analysis. The results demonstrate that the size and amount of aqueous cores in the microspheres can be tuned by the original structure of the multiple emulsions: when the volume fraction of inner water is 0.2, the inner structure of the microspheres obtained is porous and each pore is not interconnected; when the volume fraction of inner water is increased to 0.7, the resulting products are hollow microspheres and when 0.3% wt/vol of salt is added to the inner aqueous phase, the inner pores of the resulting microspheres enlarge or even coalesce. The multi‐hollow or hollow polystyrene microspheres with aqueous cores are expected to be candidates for encapsulation in biotechnology. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39761.