Synthesis of multiple-shelled organosilica hollow nanospheres via a dual-template method by using compressed CO2

A facile and sustainable approach for preparation of multiple-shelled hollow periodic mesoporous organosilicas (PMOs) nanospheres with adjustable shells thickness has been established by a dual-template method without any other extra additions. Triblock copolymer Pluronic P123 and cationic and anionic mixed surfactant (CTAB/SDS) were employed as dual templates and 1,4-Bis(triethoxysilyl) benzene (BTEB) was used as the organicsilica precursor. In the synthesis, single and multiple-shelled hollow nanospheres were synthesized with different CO2 pressures. Moreover, the shell thickness of hollow PMOs nanospheres could be tuned simply by adjusting the CO2 pressure. TEM, SAXS, N2 adsorption-desorption, solid-state NMR, and FTIR were employed to character the structure and component of the prepared PMOs. For their unique multiple-shelled structure, the obtained PMOs nanospheres were used as the drug carrier to demonstrate the high uploading and controlled release of an anti-cancer drug doxorubicin. The versatility of this method was demonstrated with the preparation of hollow PMO nanospheres from other surfactants.