ABSTRACT The engineering of porosity in common materials with oxide surfaces is reviewed. The modifications on the mesoporous silica’s and the microporous zeolites are discussed, including a silanation or a boranation of their surfaces. The reaction mechanisms are quite similar in both cases, but for the mesoporous materials the modifications hardly affect the porosity, while in zeolites a controlled pore size reduction is performed. For silica type materials, some case studies are described: the reaction with aminosilanes (aminopropyltriethoxysilane, (C2H5O)3SiC3H6NH2) in the liquid phase; chlorosilylation reactions with SiCl4 following the ‘chemical surface coating’ technique. The density of active surface groups on silica determines the type and amount of reaction. For zeolites internal and external modifications of the structure are possible. By the described chemical reactions, the surface characteristics of the solids can be varied, creating new applications in the field of adsorption and catalysis.
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