Alternatively for mipdatabase quick searches go here

Custom Search

Abstract: Periodic mesoporous organosilicas (PMOs) with diethylbenzene bridging groups (DEB) in the pore walls are promising adsorbents for harmful compounds including nitroenergetics. The hierarchical macropore-mesopore structures developed here are expected to facilitate diffusion for such applications and to offer the potential for application in column formats. DEB-functionalized PMOs were synthesized with triblock copolymer Pluronic«P123 and the swelling additive mesitylene. Many of the materials were prepared through co-condensation of the DEB precursor bis(trimethoxysilylethyl)benzene with 1,2-bis(trimethoxysilyl)ethane (BTE) to improve mesostructure. Conditions were optimized to form micron-scale macropores by polymerization-induced phase separation. PMOs were also produced using only the DEB precursor. These materials exhibited relatively high surface areas (ca. 400ám2/g) and mesopore sizes (ca. 45á+) as well as isolated macropores. As-synthesized materials were fabricated as centimeter-scale monoliths that became powders after multiple solvent refluxes. Soxhlet extraction could be used to preserve monolithic morphology while removing enough P123 to access mesopores. Nitrogen sorption, powder X-ray diffraction, SEM, TEM, and TGA were applied to characterize the PMOs
Author keywords: Macroporous monolith, Periodic mesoporous organosilica, Bis(trimethoxysilylethyl)benzene, Hierarchical material, Polymerization-induced phase separation