High Surface Area, Thermally Stable, Hydrophobic, Microporous, Rigid Gels Generated at Ambient from MeSi(OEt)3/(EtO)3SiCH2CH2Si(OEt)3 Mixtures by F−‐Catalyzed Hydrolysis

Abstract

High surface area materials are of considerable interest for gas storage/capture, molecular sieving, catalyst supports, as well as for slow‐release drug‐delivery systems. We report here a very simple and fast route to very high surface area, mechanically robust, hydrophobic polymer gels prepared by fluoride‐catalyzed hydrolysis of mixtures of MeSi(OEt)3 and bis‐triethoxysilylethane (BTSE) at room temperature. These materials offer specific surface areas up to 1300 m2 g−1, peak pore sizes of 0.8 nm and thermal stabilities above 200 °C. The gelation times and surface areas can be controlled by adjusting the solvent volume (dichloromethane), percent fluoride (as nBu4NF or TBAF) and the BTSE contents. Polymers with other corners and linkers were also explored. These materials will further expand the materials databank for use in vacuum insulation panels and as thermally stable release and capture media.Simple fluoride‐catalyzed polymerization of methyltriethoxysilane and bistriethyoxysilylethane leads to the formation of amorphous materials with little post‐synthesis processing. These materials have surface areas up to 1300 m2 g−1, densities as low as 0.06 g mL−1 and non‐polar solvent uptake of about 500 % by mass.