Preparation of hollow poly (styrene-co-divinylbenzene) particles with variable cavity sizes and further fabrication of hollow TiO2 particles using solid poly (styrene-co-divinylbenzene) particles as templates

Hollow poly (styrene-co-divinylbenzene) (PS-DVB) particles in nanometer scale with variable cavity sizes were prepared by a facile method only including both synthesis of core–shell PS-DVB particles (CSPPs) with uncross-linked core and cross-linked shell by soap-free emulsion polymerization and dissolution of uncross-linked cores of CSPPs by tetrachloromethane. The TEM results indicated that the cavity size of hollow PS-DVB particles could be controlled by adjusting the content of DVB during the polymerization process. Further hollow TiO2 particles were successfully prepared using CSPPs with 20 wt% DVB as template with the assistance of supercritical CO2 (SCCO2). The formation mechanism behind these phenomena was proposed.