Cellular mesoscopically organized silica monoliths with tailored surface chemistry by one-step drying/extraction/surface modification processes

Abstract

Large, low density silica monoliths with a hierarchical organisation of macro- and periodically arranged mesopores were obtained in a one-step procedure by treatment of as-synthesized wet gels with trimethylchlorosilane. This approach does not only offer the possibility to simultaneously achieve drying of the gel body and extraction of the block copolymer surfactant while preserving a monolithic body but also allows a viable access to surface modification. Monolithic gels from different drying procedures with or without extraction of the templating agent and supercritical drying in carbon dioxide are compared to the ones from treatment with trimethylchlorosilane. The choice of post-treatment and drying protocol offers the possibility to deliberately tailor the surface chemistry of these hierarchically organized silica monoliths.