Mesoscopic organosilicas were synthesized with bis(triethoxysilyl)ethane (BTSE) and cetyltrimethylammonium chloride (CTAC) under basic conditions. Further functionalization was achieved by co-condensation with trialkoxyorganosilanes. Surfactant extraction produced periodic mesoporous organosilicas (PMO's) functionalized with the respective organosilane pendent groups. Organosilanes used in this study include: 3-aminopropyltrimethoxysilane, n-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 2-(trimethoxysilylethyl)pyridine, n-(3-triethoxysilylpropyl)-4,5-dihydroimidazole, phenethyltrimethoxysilane, and benzyltriethoxysilane. These materials have been characterized by nitrogen gas adsorption, powder X-ray diffraction (XRD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), elemental analysis (EA), and high-resolution thermogravimetric analysis (TGA). The effect of organosilane incorporation on the porous structure of these materials is examined.

Methylene-, ethylene-, and phenylene-bridged periodic mesoporous organosilicas (PMOs) synthesized with nonionic alkylethylene oxide templates exhibited significantly better mechanical and hydrothermal stabilities than periodic mesoporous silica. Synthesis of PMOs utilized the acid-catalyzed hydrolysis and condensation of bis(triethoxysilyl) precursors around supramolecular polyoxyethylene(10) stearyl ether (Brij 76) templates. Nitrogen gas sorption, thermogravimetry, and X-ray diffraction have been used to characterize the effects of aging, mechanical compression, and hydrothermal treatment on these materials. Both as-synthesized composites containing surfactant templates and extracted PMOs showed no degradation after 10 months. The enhanced stability of these nanoporous organosilicas relative to meoporous silica makes them potential candidates for use in advanced catalysis and adsorption applications.

Ordered mesoporous materials have been synthesized by co-condensation of bis(triethoxysilyl)ethane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AAPTS) under basic conditions with supramolecular templates of cetyltrimethylammonium chloride as structure-directing agents. Incorporation of the templates into the mesoscopic composite was followed by surfactant extraction to form periodic mesoporous organosilicas. These materials have been characterized by powder X-ray diffraction, nitrogen gas sorption, metal ion adsorption, elemental analysis, and high resolution thermogravimetric analysis. The effects of AAPTS concentration in the initial solutions on the chemical and structural properties of the final products are examined.

Large pore periodic mesoporous organosilicas have been synthesized using a triblock copolymer template. Organosilicas with pore sizes ranging from 6−20 nm have been prepared under acidic conditions.

Arylene- and ethylene-bridged polysilsesquioxane materials have been synthesized by the hydrolysis and condensation of alkoxysilyl precursors under basic conditions. Cetyltrimethylammonium chloride was used to increase the porosity and surface areas of these materials via the surfactanttemplate approach. Structural characterization of these materials was carried out by nitrogen gas sorption and X-ray diffraction. The adsorption of three phenolic compounds (4-nitrophenol, 4-chlorophenol, 4-methylphenol) has been investigated by both batch and column testing. The arylene-bridged material exhibited a much greater affinity for all three phenols. The efficient removal of adsorbed phenols by a simple ethanol wash led to sorbent regeneration and separation of the aromatic species.