Aerosol-assisted synthesis of mesoporous organosilica microspheres with controlled organic contents

Periodic mesoporous organosilica (PMO) spherical particles with different organic contents were synthesized in one pot by reacting 1,2-bis(triethoxysilyl)ethane (BTSE) with tetraethylorthosilicate (TEOS) using a spray-drying technique. The scanning electron microscopy observation of spray-dried products clearly showed the formation of spherical particles. The Si-29 magic angle spinning nuclear magnetic resonance data revealed that the organic contents due to ethane fragments embedded in the frameworks were controllable and consistent with the BTSE/TEOS molar ratios of precursor solutions. Transmission electron microscopy, small-angle x-ray scattering, and N-2 adsorption data of PMO with controlled organic contents indicated that the ethane fragments were embedded in the frameworks with the formation of ordered mesostructures. PMO with a high organic content (BTSE/TEOS = 0.50) only showed a hydrophobic property. According to the same procedure, benzene groups were also integrated to a similar degree in the frameworks by using 1,4-bis(triethoxysilyl)benzene.