This research reports the use of organic-modified mesoporous silica particles as fillers to form organic/inorganic nanocomposites with improved thermal and mechanical properties. The particle fillers were synthesized by co-assembly of surfactant and silicate species prepared by hydrolysis and condensation reactions of tetraethoxysilane (TEOS) and (3-trimethoxysilyl)propyl methacrylate (TMSPMA) through an aerosol process. Selective surfactant removal resulted in mesoporous particles with high surface areas and with covalently bound propyl methacrylate ligands on the pore surface as indicated by XRD, TEM, N2 adsorption−desorption, FTIR, 13C NMR, 29Si NMR, and other techniques. Infiltration and subsequent in situ polymerization of (3-trimethoxysilyl)propyl methacrylate within and among the mesoporous silica particles result in nanocomposites with improved mechanical and thermal properties. Mechanical testing shows a significant increase in tensile strength, modulus, and toughness of the nanocomposites with little sacrifice on the elongation relative to the bulk poly((3-trimethoxysilyl)propyl methacrylate). DSC and SEM results indicate that chemical bonding and strong interactions between the polymer and filler, confined segmental motion of the polymer chains within the mesoporous channels, and the use of the silica particles as pseudo-cross-linking points may contribute to the improved mechanical properties.

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Five new phenolic compounds, gramniphenols C-G (1-5), and eight known compounds (6-13) were isolated from the whole plant of Arundina gramnifolia. Compounds 1, 4, and 5 showed anti-tobacco mosaic virus activity, with IC(50) values of 20.8, 40.8, and 57.7 μM, respectively. Compounds 1-10 were also tested for their anti-HIV-1 activity; compounds 2, 3, and 6 displayed anti-HIV-1 activity with therapeutic index values above 100:1.

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A general, aerosol-based, one-step approach was explored to synthesize microporous and mesoporous spherical carbon particles with highly porous foam-like structures from aqueous sucrose solutions containing colloidal silica particles and/or silicate cluster templates.

Aspergillines A-E (1-5) are highly oxygenated cyclopiazonic acid (CPA)-derived alkaloids bearing a rigid and sterically congested hexacyclic indole-tetrahydrofuran-tetramate scaffold, isolated from the endophytic fungus Aspergillus vesicolor. Apergillines A-C represent a new subclass of CPA-derived alkaloids, and aspergillines B and E possess a butanoic acid methyl ester moiety. The structures, including absolute configuration, were elucidated by interpretation of the NMR, X-ray crystallographic, and circular dichroism data. All compounds displayed anti-TMV and cytotoxic activities.

Ordered organic functionalized mesoporous silica containing covalently bonded diphenylphosphinoethyl ligands was synthesized using a surfactant-templating approach. Briefly, hydrolysis and condensation reactions of tetraethyl orthosilicate (TEOS) and 2-(diphenylphosphino)ethyl triethoxysilane (PPETS) in an acidic condition produced phosphino-ligand containing organosilicate species. Subsequent co-assembly of the organosilicate species with surfactants led to the formation of ordered organic/inorganic nanocomposites. Selective surfactant removal by controlled thermal decomposition created organic functionalized mesoporous silica with diphenylphosphinoethyl ligands covalently bonded to the silica framework. Pore structures and pore sizes of the functionalized mesoporous silica were controlled by using different surfactants such as P123, F127, Brij-58, and CTAB. It was found that the added organosilane may significantly affect the mesostructure possibly through participating in the cooperative assembly process. These organic functionalized mesoporous silicas were bonded with palladium ions, resulting in the formation of catalytically active organometallic complexes that show excellent activities in both Heck and epoxides allylation reactions. Compared with the conventional homogeneous catalysts, these heterogeneous organometallic complexes can be readily separated from the reaction systems and reused without deteriorating their catalytic activities. This study provides a direct synthesis approach to efficiently synthesize a large variety of organic functionalized mesoporous silica with controlled pore sizes, pore surface chemistry, and pore structure for heterogeneous catalysts and other applications.

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