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R P Hapanowicz - One of the best experts on this subject based on the ideXlab platform.
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vibrational spectral structural changes from the hydrolysis polycondensation of methyl modified silicates iv ir spectral comparisons from the Tetramethoxysilane methyitrimethoxysilane diethoxydimethyisilane system
Materials Letters, 1994Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Comparisons were made for the structures of condensates from the ternary Tetramethoxysilane (TMOS)/methyltrimethoxysilane (MTMS)/diethoxydimethylsilane (DEDMS) system and the binary MTMS/DEDMS system upon hydrolysis/polycondensation using infrared spectra. Spectral data indicated that all generated condensates possessed four-membered (Si-O) 4 rings as structural units within their structures.
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Vibrational spectral/structural changes from the hydrolysis/polycondensation of methyl-modified silicates. IV. IR spectral comparisons from the Tetramethoxysilane/ methyItrimethoxysilane / diethoxydimethyIsilane system
Materials Letters, 1994Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Comparisons were made for the structures of condensates from the ternary Tetramethoxysilane (TMOS)/methyltrimethoxysilane (MTMS)/diethoxydimethylsilane (DEDMS) system and the binary MTMS/DEDMS system upon hydrolysis/polycondensation using infrared spectra. Spectral data indicated that all generated condensates possessed four-membered (Si-O) 4 rings as structural units within their structures.
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infrared spectral structural investigation of the heat treatment of Tetramethoxysilane diethoxydimethylsilane derived gels
Spectroscopy Letters, 1993Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Structural changes occurring during the heat treatment of gels that were prepared from binary Tetramethoxysilane (TMOS)/diethoxydimethylsilane (DEDMS) mixtures were investigated using infrared spectra. Analysis of the spectral data indicated that the Si-O networks of the heat-treated gels increased their connectivity with increased dehydration due to increased treatment temperature or time. Four- and three-membered (Si-O)n rings were noted for appropriate heat-treated gel compositions. At higher heat-treatment temperatures, methyl groups were removed from the gel network.
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Infrared Spectral/Structural Investigation of the Heat Treatment of Tetramethoxysilane/Diethoxydimethylsilane-Derived Gels
Spectroscopy Letters, 1993Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Structural changes occurring during the heat treatment of gels that were prepared from binary Tetramethoxysilane (TMOS)/diethoxydimethylsilane (DEDMS) mixtures were investigated using infrared spectra. Analysis of the spectral data indicated that the Si-O networks of the heat-treated gels increased their connectivity with increased dehydration due to increased treatment temperature or time. Four- and three-membered (Si-O)n rings were noted for appropriate heat-treated gel compositions. At higher heat-treatment temperatures, methyl groups were removed from the gel network.
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vibrational spectral structural changes from the hydrolysis polycondensation of methyl modified silicates ii comparisons for condensates from the binary diethoxydimethylsilane Tetramethoxysilane system
Materials Letters, 1992Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Comparisons were made for the structures of condensates from the Tetramethoxysilane (TMOS)/diethoxydimethylsilane (DEDMS) system upon hydrolysis/polycondensation using infrared and Raman spectra. Spectral data indicated that all generated condensates possessed four-membered (Siz.sbnd;O) 4 rings as structural units within their structures. Three-membered rings appeared at lower concentrations.
C A Capozzi - One of the best experts on this subject based on the ideXlab platform.
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vibrational spectral structural changes from the hydrolysis polycondensation of methyl modified silicates iv ir spectral comparisons from the Tetramethoxysilane methyitrimethoxysilane diethoxydimethyisilane system
Materials Letters, 1994Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Comparisons were made for the structures of condensates from the ternary Tetramethoxysilane (TMOS)/methyltrimethoxysilane (MTMS)/diethoxydimethylsilane (DEDMS) system and the binary MTMS/DEDMS system upon hydrolysis/polycondensation using infrared spectra. Spectral data indicated that all generated condensates possessed four-membered (Si-O) 4 rings as structural units within their structures.
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Vibrational spectral/structural changes from the hydrolysis/polycondensation of methyl-modified silicates. IV. IR spectral comparisons from the Tetramethoxysilane/ methyItrimethoxysilane / diethoxydimethyIsilane system
Materials Letters, 1994Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Comparisons were made for the structures of condensates from the ternary Tetramethoxysilane (TMOS)/methyltrimethoxysilane (MTMS)/diethoxydimethylsilane (DEDMS) system and the binary MTMS/DEDMS system upon hydrolysis/polycondensation using infrared spectra. Spectral data indicated that all generated condensates possessed four-membered (Si-O) 4 rings as structural units within their structures.
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infrared spectral structural investigation of the heat treatment of Tetramethoxysilane diethoxydimethylsilane derived gels
Spectroscopy Letters, 1993Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Structural changes occurring during the heat treatment of gels that were prepared from binary Tetramethoxysilane (TMOS)/diethoxydimethylsilane (DEDMS) mixtures were investigated using infrared spectra. Analysis of the spectral data indicated that the Si-O networks of the heat-treated gels increased their connectivity with increased dehydration due to increased treatment temperature or time. Four- and three-membered (Si-O)n rings were noted for appropriate heat-treated gel compositions. At higher heat-treatment temperatures, methyl groups were removed from the gel network.
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Infrared Spectral/Structural Investigation of the Heat Treatment of Tetramethoxysilane/Diethoxydimethylsilane-Derived Gels
Spectroscopy Letters, 1993Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Structural changes occurring during the heat treatment of gels that were prepared from binary Tetramethoxysilane (TMOS)/diethoxydimethylsilane (DEDMS) mixtures were investigated using infrared spectra. Analysis of the spectral data indicated that the Si-O networks of the heat-treated gels increased their connectivity with increased dehydration due to increased treatment temperature or time. Four- and three-membered (Si-O)n rings were noted for appropriate heat-treated gel compositions. At higher heat-treatment temperatures, methyl groups were removed from the gel network.
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vibrational spectral structural changes from the hydrolysis polycondensation of methyl modified silicates ii comparisons for condensates from the binary diethoxydimethylsilane Tetramethoxysilane system
Materials Letters, 1992Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Comparisons were made for the structures of condensates from the Tetramethoxysilane (TMOS)/diethoxydimethylsilane (DEDMS) system upon hydrolysis/polycondensation using infrared and Raman spectra. Spectral data indicated that all generated condensates possessed four-membered (Siz.sbnd;O) 4 rings as structural units within their structures. Three-membered rings appeared at lower concentrations.
R A Condrate - One of the best experts on this subject based on the ideXlab platform.
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vibrational spectral structural changes from the hydrolysis polycondensation of methyl modified silicates iv ir spectral comparisons from the Tetramethoxysilane methyitrimethoxysilane diethoxydimethyisilane system
Materials Letters, 1994Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Comparisons were made for the structures of condensates from the ternary Tetramethoxysilane (TMOS)/methyltrimethoxysilane (MTMS)/diethoxydimethylsilane (DEDMS) system and the binary MTMS/DEDMS system upon hydrolysis/polycondensation using infrared spectra. Spectral data indicated that all generated condensates possessed four-membered (Si-O) 4 rings as structural units within their structures.
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Vibrational spectral/structural changes from the hydrolysis/polycondensation of methyl-modified silicates. IV. IR spectral comparisons from the Tetramethoxysilane/ methyItrimethoxysilane / diethoxydimethyIsilane system
Materials Letters, 1994Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Comparisons were made for the structures of condensates from the ternary Tetramethoxysilane (TMOS)/methyltrimethoxysilane (MTMS)/diethoxydimethylsilane (DEDMS) system and the binary MTMS/DEDMS system upon hydrolysis/polycondensation using infrared spectra. Spectral data indicated that all generated condensates possessed four-membered (Si-O) 4 rings as structural units within their structures.
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infrared spectral structural investigation of the heat treatment of Tetramethoxysilane diethoxydimethylsilane derived gels
Spectroscopy Letters, 1993Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Structural changes occurring during the heat treatment of gels that were prepared from binary Tetramethoxysilane (TMOS)/diethoxydimethylsilane (DEDMS) mixtures were investigated using infrared spectra. Analysis of the spectral data indicated that the Si-O networks of the heat-treated gels increased their connectivity with increased dehydration due to increased treatment temperature or time. Four- and three-membered (Si-O)n rings were noted for appropriate heat-treated gel compositions. At higher heat-treatment temperatures, methyl groups were removed from the gel network.
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Infrared Spectral/Structural Investigation of the Heat Treatment of Tetramethoxysilane/Diethoxydimethylsilane-Derived Gels
Spectroscopy Letters, 1993Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Structural changes occurring during the heat treatment of gels that were prepared from binary Tetramethoxysilane (TMOS)/diethoxydimethylsilane (DEDMS) mixtures were investigated using infrared spectra. Analysis of the spectral data indicated that the Si-O networks of the heat-treated gels increased their connectivity with increased dehydration due to increased treatment temperature or time. Four- and three-membered (Si-O)n rings were noted for appropriate heat-treated gel compositions. At higher heat-treatment temperatures, methyl groups were removed from the gel network.
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vibrational spectral structural changes from the hydrolysis polycondensation of methyl modified silicates ii comparisons for condensates from the binary diethoxydimethylsilane Tetramethoxysilane system
Materials Letters, 1992Co-Authors: C A Capozzi, R A Condrate, R P HapanowiczAbstract:Abstract Comparisons were made for the structures of condensates from the Tetramethoxysilane (TMOS)/diethoxydimethylsilane (DEDMS) system upon hydrolysis/polycondensation using infrared and Raman spectra. Spectral data indicated that all generated condensates possessed four-membered (Siz.sbnd;O) 4 rings as structural units within their structures. Three-membered rings appeared at lower concentrations.
W C De Castro - One of the best experts on this subject based on the ideXlab platform.
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Structural study of aged saturated silica gels obtained from Tetramethoxysilane sonohydrolysis with different water/Tetramethoxysilane molar ratio
Physical Review B, 2003Co-Authors: D R Vollet, D A Donatti, A. Ibañez Ruiz, W C De CastroAbstract:The structural characteristics of saturated silica sonogels were studied by means of small-angle x-ray scattering (SAXS) and thermogravimetric analysis (TG), after a long time of aging in saturated conditions. The sonogels were obtained by a sol-gel routine from ultrasound stimulated Tetramethoxysilane (TMOS) hydrolysis carried out with the initial water/TMOS molar ratio (r) ranging from 2 to 10. The saturated sonogel structure can be described as composed by mass fractal-like aggregates (clusters) of primary silica particles, all imbibed in a liquid phase. The values of the mass fractal dimension (D) of the clusters was found all around 2.5, while the characteristic size of the clusters (ξ) was found generally increasing with r, going from approximately 2.3 nm (r=2) to 4.5 nm (r= 10). The volume fraction of the clusters was estimated from the SAXS data. The results were compared to the values of weight loss fraction at the inflection point that has been found in the derivative of the TG curve, which should accounts for the instant in which the meniscus of the liquid phase penetrates into the clusters under a rapid evaporation process as in a TG test.
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structural study of aged saturated silica gels obtained from Tetramethoxysilane sonohydrolysis with different water Tetramethoxysilane molar ratio
Physical Review B, 2003Co-Authors: D R Vollet, D A Donatti, Ibanez A Ruiz, W C De CastroAbstract:The structural characteristics of saturated silica sonogels were studied by means of small-angle x-ray scattering (SAXS) and thermogravimetric analysis (TG), after a long time of aging in saturated conditions. The sonogels were obtained by a sol-gel routine from ultrasound stimulated Tetramethoxysilane (TMOS) hydrolysis carried out with the initial water/TMOS molar ratio (r) ranging from 2 to 10. The saturated sonogel structure can be described as composed by mass fractal-like aggregates (clusters) of primary silica particles, all imbibed in a liquid phase. The values of the mass fractal dimension (D) of the clusters was found all around 2.5, while the characteristic size of the clusters (ξ) was found generally increasing with r, going from approximately 2.3 nm (r=2) to 4.5 nm (r= 10). The volume fraction of the clusters was estimated from the SAXS data. The results were compared to the values of weight loss fraction at the inflection point that has been found in the derivative of the TG curve, which should accounts for the instant in which the meniscus of the liquid phase penetrates into the clusters under a rapid evaporation process as in a TG test.
Kazuyuki Kuroda - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Layered Inorganic−Organic Nanocomposite Films from Mono-, Di-, and Trimethoxy(alkyl)silane−Tetramethoxysilane Systems
Chemistry of Materials, 2001Co-Authors: Atsushi Shimojima, Noritaka Umeda, Kazuyuki KurodaAbstract:Transparent thin films of layered inorganic−organic nanocomposites were prepared by the sol−gel reactions of alkyldimethylmethoxysilane, alkylmethyldimethoxysilane, and alkyltrimethoxysilane in the presence of Tetramethoxysilane followed by spin-coating. The macroscopic homogeneity and the nanostructural ordering of the films were strongly affected by the degree of polycondensation in the precursor solutions. The formation of siloxane networks containing organosiloxane units was confirmed by 29Si MAS NMR, suggesting that the structure of the inorganic−organic interface can be designed at a molecular level by the functionalities in the alkylmethoxysilanes used. On the other hand, the 29Si NMR spectra of the precursor solutions showed that the monomeric species almost disappeared and that co-condensed oligomers were formed at the initial stages of the reactions. In the cases of mono- and dimethoxysilanes, the ability to form ordered structures depends largely on the co-condensation with Tetramethoxysilane i...
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synthesis of layered inorganic organic nanocomposite films from mono di and trimethoxy alkyl silane Tetramethoxysilane systems
Chemistry of Materials, 2001Co-Authors: Atsushi Shimojima, Noritaka Umeda, Kazuyuki KurodaAbstract:Transparent thin films of layered inorganic−organic nanocomposites were prepared by the sol−gel reactions of alkyldimethylmethoxysilane, alkylmethyldimethoxysilane, and alkyltrimethoxysilane in the presence of Tetramethoxysilane followed by spin-coating. The macroscopic homogeneity and the nanostructural ordering of the films were strongly affected by the degree of polycondensation in the precursor solutions. The formation of siloxane networks containing organosiloxane units was confirmed by 29Si MAS NMR, suggesting that the structure of the inorganic−organic interface can be designed at a molecular level by the functionalities in the alkylmethoxysilanes used. On the other hand, the 29Si NMR spectra of the precursor solutions showed that the monomeric species almost disappeared and that co-condensed oligomers were formed at the initial stages of the reactions. In the cases of mono- and dimethoxysilanes, the ability to form ordered structures depends largely on the co-condensation with Tetramethoxysilane i...
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Preparation of Transparent Silica-Surfactant Nanocomposite Films with Controlled Microstructures
Bulletin of the Chemical Society of Japan, 1997Co-Authors: Makoto Ogawa, Takanori Igarashi, Kazuyuki KurodaAbstract:Novel silica-alkyltrimethylammonium (with the alkyl groups of decyl, dodecyl, tetradecyl, hexadecyl, and octadecyl) bromide nanocomposite films were synthesized by coating the precursor solutions containing prehydrolyzed Tetramethoxysilane and alkyltrimethylammonium bromide. The composites are thought to be composed of aggregates of alkyltrimethylammonium bromides and thin silica layers. The d values of the products varied depending on the relative ratios of Tetramethoxysilane and surfactants, suggesting that the microstructures of the products can be controlled by simply changing the compositions. Since the present composites are obtained as transparent films, they have potential applicability as a new class of functional materials, especially for photofunctional purposes.
