Sol—Gel Processing of a Glycolated Cyclic Organosilane and Its Pyrolysis to Silicon Oxycarbide Monoliths with Multiscale Porosity and Large Surface Areas

This study is related to the preparation of silicon oxycarbide monoliths comprising a hierarchical network build-up from the pyrolysis of monolithic organosilica gels. A novel glycol-modified 1,3,5-trisilacyclohexane-carbosilane “[Si(OCH2CH2OH)2CH2]3” was processed via a polymerization-induced phase separation process in hydrochloric acid solution containing the Pluronic P123 block copolymer and potassium chloride. Highly porous organosilica monoliths with interconnected macropores and a large amount of uniformly sized polymer-templated mesopores within the macroscopic framework domains were obtained after supercritical fluid extraction. The monoliths were pyrolyzed in argon atmosphere at 1000 °C to yield silicon oxycarbide monoliths by maintaining the hierarchical porosity of the organosilica gel. Both the organosilica gels and the silicon oxycarbide monoliths were thoroughly investigated with standard characterization techniques. If no salt was used for the preparation of organosilica gels, no distinct ...