Molecularly Ordered Ethylene-Bridged Periodic Mesoporous Organosilica Spheres with Tunable Micrometer Sizes

We report the synthesis of periodic mesoporous organosilica (PMO) spheres of a size between 3 and 14 μm. The ethylene-bridged PMO spheres were prepared via surfactant (dodecyltrimethylammonium bromide) mediated assembly of 1,2-bis(triethoxysilyl)ethylene without using any additional cosolvents and/or cosurfactants. The PMO spheres exhibit molecular-scale ordering with a periodicity of 5.6 Å due to a crystal-like arrangement of the ethylene groups in the organosilica framework. The morphology (i.e., formation of spheres) and level of mesostructural ordering in the PMO materials were dependent on the basicity of the synthesis media, while the size of the relatively monodisperse spheres was readily controlled by variations in the concentration of surfactant. The PMO materials are mesostructurally well-ordered and exhibit a high surface area (>900 m 2 /g) and pore volume (>0.8 cm 3 /g). The molecularly ordered ethylene groups within the organosilica framework were found to present a versatile and reactive functionality as demonstrated by bromination of the PMO spheres.