Organic groups functionalised mesoporous silicates

Abstract

Great interests have been imparted on organically modified mesoporous silica materials due to their high surface areas, uniform pore sizes and integrated functionality. Besides the inherent character of inorganic and organic components, the interactions between them should also be recognised for the synthesis, including organic-group loading, mesostructure and particle morphology, condensation, as well as organic-group distribution. To obtain long range ordered hybrid materials, several factors, such as relative hydrolysis and condensation rates of the inorganic and organic sources, chemical character such as hydrophobicity/hydrophilicity and acid/base of organic ligand as well as the surfactant category, should be surveyed. A concept of 'combinatorial synthesis' is introduced here for the cases of combining two or more functional units in a typical synthesis into a single one. The silica precursors in the preparation of periodic mesoporous organosilanes (PMOs) are the aggregation of inorganic and organic silicates. The assembly will lead to a unique distribution and high concentration of functional groups. Both the confinement within the mesopores and the pore surface nature will affect the accessibility to the active sites, and therefore, the adsorption and relative applications. These characters win them ample host-guest chemistry. They can seek the opportunities in the fields of catalysis, separation, electronic devices, biomedicines, nanomaterial fabrication, etc.