Mesoporous poly(styrene-co-maleic anhydride)/silica hybrid materials have been prepared. The synthesis was achieved by the HCl-catalyzed sol-gel reactions of tetraethyl orthosilicate (TEOS) and styrene-maleic anhydrid...Mesoporous poly(styrene-co-maleic anhydride)/silica hybrid materials have been prepared. The synthesis was achieved by the HCl-catalyzed sol-gel reactions of tetraethyl orthosilicate (TEOS) and styrene-maleic anhydride copolymer in the presence of 3-aminopropyl triethoxysilane (APTES) as a coupling agent and citric acid as a nonsurfactant template or pore-forming agent, followed by ethanol extraction. Characterization results from nitrogen sorption isotherms and powder X-ray diffraction indicate that polymer-modified mesoporous materials with large specific surface areas (e.g. 900 m(2)/g) and pore volumes (e.g. 0.6 cm(3)/g) could be prepared. As the citric acid concentration is increased, the specific surface areas, pore volumes and pore diameters of the hybrid materials increase.展开更多
Functionalized silica hybrid materials are extensively studied and applied materials in the field of science and technology. Functionalization is an approach, which allows for the application of organic components in ...Functionalized silica hybrid materials are extensively studied and applied materials in the field of science and technology. Functionalization is an approach, which allows for the application of organic components in the improvement of the design, properties and potential application of silicate materials. Silica hybrid materials, functionalized via incorporation of organic components (chitosan and methacrylic acid) were synthesized by the sol-gel method. The base silica structure of the hybrids was obtained via hydrolysis and condensation of the silicate precursor, tetraethyl orthosilicate. The investigations of synthesized hybrids are focused on the influence of the nature and quantity of functional organic components on their final structures and properties. The structural characteristics of obtained hybrid materials were investigated using XRD, FTIR, SEM and DTA/TG analysis. The obtained results presented the formation of amorphous porous structure and the organic components are evenly distributed into the silica network. The functional radicals of chitosan and methacrylic acid (amine, hydroxyl groups) exist in the hybrid structure as free reactive centers, as their quantity increases with increasing the organic amount. The swelling behavior in acidic and neutral solutions of the synthesized materials is investigated and the results presented, that the silicate materials exhibit hydrophilic character.展开更多
A polystyrene（PS）/nanosilica organic-inorganic hybrid material was prepared from styrene monomer and commercial aqueous silica sol containing large amounts of Si-OH by means of emulsion polymerization. The nanosilic...A polystyrene（PS）/nanosilica organic-inorganic hybrid material was prepared from styrene monomer and commercial aqueous silica sol containing large amounts of Si-OH by means of emulsion polymerization. The nanosilica sol was modified by the addition of the reactive coupling agent methacrylexy propyltrimethoxysilane （ MPS）, and the resulting latex particles were protected by surfactants such as sodium dodecyl sulphonate（ SDS）, hydroxypropyl methyl cellulose （ HMPC）, and poly （vinylpyrrolidone） （PVP）. The effects of the type of surfactant, the amount of surfactant, and the coupling agent on the shape and stability of the resulting latex particles were investigated. The TEM observation indicates that among SDS, HMPC, and PVP, SDS is the best surfactant. When the content of SDS is 0. 5% and the amount of MPS is 7% in the system, the latex with obvious core-shell structure could be obtained. The average diameters of the monodispersed particles range from 182 to 278 nm, and the average number of silica beads for each composite are 1325 and 4409, respectively. The FrIR analysis shows that PS was chemically linked to silica through MPS. The thermal gravimetric analysis shows that when there is a higher silica content, the hybrid composites have a better heat resistance.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 29874002) and the Outstanding Young Scientist Award from National Natural Science Foundation of China (No. 29825504)
文摘Mesoporous poly(styrene-co-maleic anhydride)/silica hybrid materials have been prepared. The synthesis was achieved by the HCl-catalyzed sol-gel reactions of tetraethyl orthosilicate (TEOS) and styrene-maleic anhydride copolymer in the presence of 3-aminopropyl triethoxysilane (APTES) as a coupling agent and citric acid as a nonsurfactant template or pore-forming agent, followed by ethanol extraction. Characterization results from nitrogen sorption isotherms and powder X-ray diffraction indicate that polymer-modified mesoporous materials with large specific surface areas (e.g. 900 m(2)/g) and pore volumes (e.g. 0.6 cm(3)/g) could be prepared. As the citric acid concentration is increased, the specific surface areas, pore volumes and pore diameters of the hybrid materials increase.
文摘Functionalized silica hybrid materials are extensively studied and applied materials in the field of science and technology. Functionalization is an approach, which allows for the application of organic components in the improvement of the design, properties and potential application of silicate materials. Silica hybrid materials, functionalized via incorporation of organic components (chitosan and methacrylic acid) were synthesized by the sol-gel method. The base silica structure of the hybrids was obtained via hydrolysis and condensation of the silicate precursor, tetraethyl orthosilicate. The investigations of synthesized hybrids are focused on the influence of the nature and quantity of functional organic components on their final structures and properties. The structural characteristics of obtained hybrid materials were investigated using XRD, FTIR, SEM and DTA/TG analysis. The obtained results presented the formation of amorphous porous structure and the organic components are evenly distributed into the silica network. The functional radicals of chitosan and methacrylic acid (amine, hydroxyl groups) exist in the hybrid structure as free reactive centers, as their quantity increases with increasing the organic amount. The swelling behavior in acidic and neutral solutions of the synthesized materials is investigated and the results presented, that the silicate materials exhibit hydrophilic character.
基金Supported by the National Natural Science Foundation of China(No. 50373037)the Special Funds for Major State BasicResearch Projects ( No. 2005CB623802) Specialized Research Fund for the Doctoral Program of Higher Education ( No.20040335077).
文摘A polystyrene（PS）/nanosilica organic-inorganic hybrid material was prepared from styrene monomer and commercial aqueous silica sol containing large amounts of Si-OH by means of emulsion polymerization. The nanosilica sol was modified by the addition of the reactive coupling agent methacrylexy propyltrimethoxysilane （ MPS）, and the resulting latex particles were protected by surfactants such as sodium dodecyl sulphonate（ SDS）, hydroxypropyl methyl cellulose （ HMPC）, and poly （vinylpyrrolidone） （PVP）. The effects of the type of surfactant, the amount of surfactant, and the coupling agent on the shape and stability of the resulting latex particles were investigated. The TEM observation indicates that among SDS, HMPC, and PVP, SDS is the best surfactant. When the content of SDS is 0. 5% and the amount of MPS is 7% in the system, the latex with obvious core-shell structure could be obtained. The average diameters of the monodispersed particles range from 182 to 278 nm, and the average number of silica beads for each composite are 1325 and 4409, respectively. The FrIR analysis shows that PS was chemically linked to silica through MPS. The thermal gravimetric analysis shows that when there is a higher silica content, the hybrid composites have a better heat resistance.
