Hybrid Inorganic–Organic Mesoporous Silicates—Nanoscopic Reactors Coming of Age

This review describes methods of preparing hybrid inorganic–organic mesoporous silicates with uniform channel structures, as well as some of their applications. Both reactive and passive organic groups can be incorporated in the porous solids by grafting methods or by co-condensation under surfactant control. Functional groups have been placed selectively on the internal or external pore surfaces or even within the walls of the mesoporous solids. Organic functionalization of these solids permits tuning of the surface properties (hydrophilicity, hydrophobicity, binding to guest molecules), alteration of the surface reactivity, protection of the surface from attack, and modification of the bulk properties (e.g., mechanical or optical properties) of the material. Recent applications of hybrid mesoporous silicates are highlighted, including catalysis, sorption of metals, anions, and organics, reactors for polymerization, fixation of biologically active species, and optical applications.