The Experts below are selected from a list of 798 Experts worldwide ranked by ideXlab platform
H Kido - One of the best experts on this subject based on the ideXlab platform.
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probing the nature and the structure of pores in silica xerogels by water sorption the Tetramethyl Orthosilicate hydrogen chloride fluoride system
Journal of the American Ceramic Society, 1991Co-Authors: P B Malla, Sridhar Komarneni, Hideki Taguchi, H KidoAbstract:A series of silica xerogels were synthesized in a closed system by hydrolyzing Tetramethyl Orthosilicate (TMOS) with various concentrations of hydrochloric acid solution but without the addition of alcohol. The molar ratio of H2O to TMOS was fixed at 4.96. The gels were characterized by water and nitrogen sorption measurements. The gelation time peaked at 50 to 80 h with 5 × 10−2 to 10−1M HCl, apparently a consequence of the isoelectric point of silica. Surface area, pore size, and sorption capacity were, however, at a minimum for samples prepared with 5 × 10−2 to 10−1M HCl. The BET c constant and hence the net heats of sorption were at a maximum for these samples. Although water sorption of all the samples prepared with HCl exhibited moderate Type I isotherms, the concavity of the isotherms to the P/P0 axis increased with increasing concentrations of HCl up to 10−1M in accordance with the decreased pore size and increased heat of sorption. Addition of F− ions (HF or NaF) in the presence of 10−1M HCl steadily decreased the gelation time. Addition of F− in the absence of HCl, however, caused rapid gelation and an increase in pore size, nitrogen BET surface area, and hydrophobicity. Consequently, the shape of water isotherms gradually converted to Type IV and/or Type V. Adsorption and desorption measurements on differently activated gels exhibited various types of hystereses as a result of development of hydrophobie sites at as low as 200°C, inelastic distortion induced by adsorption, and chemical reaction and aging of gels when exposed to water vapor.
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Probing the Nature and the Structure of Pores in Silica Xerogels by Water Sorption: The Tetramethyl Orthosilicate‐Hydrogen Chloride/Fluoride System
Journal of the American Ceramic Society, 1991Co-Authors: P B Malla, Sridhar Komarneni, Hideki Taguchi, H KidoAbstract:A series of silica xerogels were synthesized in a closed system by hydrolyzing Tetramethyl Orthosilicate (TMOS) with various concentrations of hydrochloric acid solution but without the addition of alcohol. The molar ratio of H2O to TMOS was fixed at 4.96. The gels were characterized by water and nitrogen sorption measurements. The gelation time peaked at 50 to 80 h with 5 × 10−2 to 10−1M HCl, apparently a consequence of the isoelectric point of silica. Surface area, pore size, and sorption capacity were, however, at a minimum for samples prepared with 5 × 10−2 to 10−1M HCl. The BET c constant and hence the net heats of sorption were at a maximum for these samples. Although water sorption of all the samples prepared with HCl exhibited moderate Type I isotherms, the concavity of the isotherms to the P/P0 axis increased with increasing concentrations of HCl up to 10−1M in accordance with the decreased pore size and increased heat of sorption. Addition of F− ions (HF or NaF) in the presence of 10−1M HCl steadily decreased the gelation time. Addition of F− in the absence of HCl, however, caused rapid gelation and an increase in pore size, nitrogen BET surface area, and hydrophobicity. Consequently, the shape of water isotherms gradually converted to Type IV and/or Type V. Adsorption and desorption measurements on differently activated gels exhibited various types of hystereses as a result of development of hydrophobie sites at as low as 200°C, inelastic distortion induced by adsorption, and chemical reaction and aging of gels when exposed to water vapor.
Kevin J. Otto - One of the best experts on this subject based on the ideXlab platform.
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EMBC - The effect of multiple thin-film coatings of protein loaded sol-gel on total multi-electrode array thickness
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and, 2016Co-Authors: Matthew D. Mcdermott, Kevin J. OttoAbstract:Tetramethyl Orthosilicate shows promise as a thin-film delivery vehicle for multi-electrode arrays for drug release and electrical performance; however, its effect upon device footprint has yet to be assessed. Using a previously established silicon wafer chip model, the thickness of one, two, and four protein doped coatings of sol-gel were analyzed via profilometry. Coating thickness was found to be 0.4μm, 1.1μm and 2.2μm on each side of the device. This addition to a native MEA is minimal when compared to other drug delivery paradigms currently associated with neural implants.
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The effect of multiple thin-film coatings of protein loaded sol-gel on total multi-electrode array thickness
2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2016Co-Authors: Matthew D. Mcdermott, Kevin J. OttoAbstract:Tetramethyl Orthosilicate shows promise as a thin-film delivery vehicle for multi-electrode arrays for drug release and electrical performance; however, its effect upon device footprint has yet to be assessed. Using a previously established silicon wafer chip model, the thickness of one, two, and four protein doped coatings of sol-gel were analyzed via profilometry. Coating thickness was found to be 0.4μm, 1.1μm and 2.2μm on each side of the device. This addition to a native MEA is minimal when compared to other drug delivery paradigms currently associated with neural implants.
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Improving the brain machine interface via multiple Tetramethyl Orthosilicate sol-gel coatings on microelectrode arrays
2015 7th International IEEE EMBS Conference on Neural Engineering (NER), 2015Co-Authors: Matthew D. Mcdermott, Johnny Zhang, Kevin J. OttoAbstract:The failure of neurally implanted microelectrode arrays has been highly correlated with the foreign body response (FBR). In order to maintain high fidelity signaling across the brain machine interface, the FBR must be minimized. Multiple thin coatings of Tetramethyl Orthosilicate have the potential to reduce the acute FBR through their ability to release a model therapeutic drug for 4 to 10 days, their positive effects on electrode performance (e.g. a minimal change in impedance at 1kHz, less than 10%, and an increase in charge carrying capacity, up to 49%), and their low impact on device thickness.
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NER - Improving the brain machine interface via multiple Tetramethyl Orthosilicate sol-gel coatings on microelectrode arrays
2015 7th International IEEE EMBS Conference on Neural Engineering (NER), 2015Co-Authors: Matthew D. Mcdermott, Johnny Zhang, Kevin J. OttoAbstract:The failure of neurally implanted microelectrode arrays has been highly correlated with the foreign body response (FBR). In order to maintain high fidelity signaling across the brain machine interface, the FBR must be minimized. Multiple thin coatings of Tetramethyl Orthosilicate have the potential to reduce the acute FBR through their ability to release a model therapeutic drug for 4 to 10 days, their positive effects on electrode performance (e.g. a minimal change in impedance at 1kHz, less than 10%, and an increase in charge carrying capacity, up to 49%), and their low impact on device thickness.
Katsuto Otake - One of the best experts on this subject based on the ideXlab platform.
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pressure volume temperature relationships of trimethoxymethylsilane and Tetramethyl Orthosilicate at temperatures ranging from 303 2 to 363 2 k and pressures up to 160 mpa
Journal of Chemical & Engineering Data, 2020Co-Authors: Hiroaki Matsukawa, Hiroyuki Suzuki, Takaaki Hoshina, Tomoya Tsuji, Katsuto OtakeAbstract:The pressure–volume–temperature (PVT) relationships for trimethoxymethylsilane (MTMS, CH3(CH3O)3Si) and Tetramethyl Orthosilicate (TMOS, (CH3O)4Si) were measured at temperatures ranging from 303.2 to 363.2 K and pressures up to 160 MPa. Density measurements were carried out with an experimental apparatus based on the variable volume method. The standard uncertainties u(T) = 0.17 K and u(P) = 0.14 MPa, and the relative combined expanded uncertainty Ur (0.95 level of confidence) were Ur(ρ) = (0.0016 and 0.0022) for MTMS and TMOS, respectively. The obtained PVT relationships were correlated using the Tait equation and the Sanchez–Lacombe equation of state to determine the characteristic parameters.
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phase behavior of carbon dioxide Tetramethyl Orthosilicate polymer ternary systems
Fluid Phase Equilibria, 2018Co-Authors: Hiroaki Matsukawa, Yuichiro Shimada, Satoshi Yoda, Yasuo Okawa, Masakazu Naya, Atsushi Shono, Katsuto OtakeAbstract:Abstract The phase behaviors of carbon dioxide (CO2)/Tetramethyl Orthosilicate (TMOS)/poly(methyl methacrylate) (PMMA) and CO2/TMOS/poly(styrene) (PS) ternary systems were measured. The measurements were performed using a synthetic method involving observations of the bubble point and cloud point. The phase boundaries were measured at temperatures ranging from 313.2 K to 393.2 K and CO2 weight fractions ranging from 0.01 to 0.40. At a constant TMOS:polymer weight ratio of 9:1, both systems showed similar CO2 mass fraction dependence of their phase behaviors. When the vapor-liquid (VL) and vapor-liquid-liquid (VLL) phase boundaries of the ternary systems were compared with those of the binary CO2/TMOS system using polymer-free bases, they were found to be nearly identical. On the other hand, the two systems showed completely opposite polymer mass fraction dependence of their phase behaviors at a constant CO2 ratio.
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Phase behavior of Carbon dioxide/Tetramethyl Orthosilicate/polymer ternary systems
Fluid Phase Equilibria, 2018Co-Authors: Hiroaki Matsukawa, Yuichiro Shimada, Satoshi Yoda, Yasuo Okawa, Masakazu Naya, Atsushi Shono, Katsuto OtakeAbstract:Abstract The phase behaviors of carbon dioxide (CO 2 )/Tetramethyl Orthosilicate (TMOS)/poly(methyl methacrylate) (PMMA) and CO 2 /TMOS/poly(styrene) (PS) ternary systems were measured. The measurements were performed using a synthetic method involving observations of the bubble point and cloud point. The phase boundaries were measured at temperatures ranging from 313.2 K to 393.2 K and CO 2 weight fractions ranging from 0.01 to 0.40. At a constant TMOS:polymer weight ratio of 9:1, both systems showed similar CO 2 mass fraction dependence of their phase behaviors. When the vapor-liquid (VL) and vapor-liquid-liquid (VLL) phase boundaries of the ternary systems were compared with those of the binary CO 2 /TMOS system using polymer-free bases, they were found to be nearly identical. On the other hand, the two systems showed completely opposite polymer mass fraction dependence of their phase behaviors at a constant CO 2 ratio.
Liang Li - One of the best experts on this subject based on the ideXlab platform.
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enhancing the stability of ch3nh3pbbr3 quantum dots by embedding in silica spheres derived from Tetramethyl Orthosilicate in waterless toluene
Journal of the American Chemical Society, 2016Co-Authors: Shouqiang Huang, Zhichun Li, Long Kong, Aidang Shan, Liang LiAbstract:Methylammonium lead halide perovskites suffer from poor stability because of their high sensitivity to moisture. Inorganic material coatings of SiO2 are preferred for coupling with perovskites to improve their stability, whereas the conventional SiO2 formation method is unsuitable because it requires water. Here, a simple SiO2 generation method based on the high hydrolysis rate of Tetramethyl Orthosilicate in analytical-grade toluene was developed to avoid the addition of water and catalyst. As a result, SiO2-encapsulated CH3NH3PbBr3 quantum dots (MAPB-QDs/SiO2) were fabricated without decreasing the quantum yield. Photostability tests indicated that the MAPB-QDs/SiO2 samples were markedly more stable than the unencapsulated MAPB-QDs. The photoluminescence (PL) of the MAPB-QDs/SiO2 powders was maintained at 94.10% after 470 nm LED illumination for 7 h, which was much higher than the remnant PL (38.36%) of the pure MAPB-QD sample under a relative humidity of 60%. Similar test results were observed when the...
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Enhancing the Stability of CH3NH3PbBr3 Quantum Dots by Embedding in Silica Spheres Derived from Tetramethyl Orthosilicate in “Waterless” Toluene
Journal of the American Chemical Society, 2016Co-Authors: Shouqiang Huang, Zhichun Li, Long Kong, Aidang Shan, Liang LiAbstract:Methylammonium lead halide perovskites suffer from poor stability because of their high sensitivity to moisture. Inorganic material coatings of SiO2 are preferred for coupling with perovskites to improve their stability, whereas the conventional SiO2 formation method is unsuitable because it requires water. Here, a simple SiO2 generation method based on the high hydrolysis rate of Tetramethyl Orthosilicate in analytical-grade toluene was developed to avoid the addition of water and catalyst. As a result, SiO2-encapsulated CH3NH3PbBr3 quantum dots (MAPB-QDs/SiO2) were fabricated without decreasing the quantum yield. Photostability tests indicated that the MAPB-QDs/SiO2 samples were markedly more stable than the unencapsulated MAPB-QDs. The photoluminescence (PL) of the MAPB-QDs/SiO2 powders was maintained at 94.10% after 470 nm LED illumination for 7 h, which was much higher than the remnant PL (38.36%) of the pure MAPB-QD sample under a relative humidity of 60%. Similar test results were observed when the...
P B Malla - One of the best experts on this subject based on the ideXlab platform.
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probing the nature and the structure of pores in silica xerogels by water sorption the Tetramethyl Orthosilicate hydrogen chloride fluoride system
Journal of the American Ceramic Society, 1991Co-Authors: P B Malla, Sridhar Komarneni, Hideki Taguchi, H KidoAbstract:A series of silica xerogels were synthesized in a closed system by hydrolyzing Tetramethyl Orthosilicate (TMOS) with various concentrations of hydrochloric acid solution but without the addition of alcohol. The molar ratio of H2O to TMOS was fixed at 4.96. The gels were characterized by water and nitrogen sorption measurements. The gelation time peaked at 50 to 80 h with 5 × 10−2 to 10−1M HCl, apparently a consequence of the isoelectric point of silica. Surface area, pore size, and sorption capacity were, however, at a minimum for samples prepared with 5 × 10−2 to 10−1M HCl. The BET c constant and hence the net heats of sorption were at a maximum for these samples. Although water sorption of all the samples prepared with HCl exhibited moderate Type I isotherms, the concavity of the isotherms to the P/P0 axis increased with increasing concentrations of HCl up to 10−1M in accordance with the decreased pore size and increased heat of sorption. Addition of F− ions (HF or NaF) in the presence of 10−1M HCl steadily decreased the gelation time. Addition of F− in the absence of HCl, however, caused rapid gelation and an increase in pore size, nitrogen BET surface area, and hydrophobicity. Consequently, the shape of water isotherms gradually converted to Type IV and/or Type V. Adsorption and desorption measurements on differently activated gels exhibited various types of hystereses as a result of development of hydrophobie sites at as low as 200°C, inelastic distortion induced by adsorption, and chemical reaction and aging of gels when exposed to water vapor.
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Probing the Nature and the Structure of Pores in Silica Xerogels by Water Sorption: The Tetramethyl Orthosilicate‐Hydrogen Chloride/Fluoride System
Journal of the American Ceramic Society, 1991Co-Authors: P B Malla, Sridhar Komarneni, Hideki Taguchi, H KidoAbstract:A series of silica xerogels were synthesized in a closed system by hydrolyzing Tetramethyl Orthosilicate (TMOS) with various concentrations of hydrochloric acid solution but without the addition of alcohol. The molar ratio of H2O to TMOS was fixed at 4.96. The gels were characterized by water and nitrogen sorption measurements. The gelation time peaked at 50 to 80 h with 5 × 10−2 to 10−1M HCl, apparently a consequence of the isoelectric point of silica. Surface area, pore size, and sorption capacity were, however, at a minimum for samples prepared with 5 × 10−2 to 10−1M HCl. The BET c constant and hence the net heats of sorption were at a maximum for these samples. Although water sorption of all the samples prepared with HCl exhibited moderate Type I isotherms, the concavity of the isotherms to the P/P0 axis increased with increasing concentrations of HCl up to 10−1M in accordance with the decreased pore size and increased heat of sorption. Addition of F− ions (HF or NaF) in the presence of 10−1M HCl steadily decreased the gelation time. Addition of F− in the absence of HCl, however, caused rapid gelation and an increase in pore size, nitrogen BET surface area, and hydrophobicity. Consequently, the shape of water isotherms gradually converted to Type IV and/or Type V. Adsorption and desorption measurements on differently activated gels exhibited various types of hystereses as a result of development of hydrophobie sites at as low as 200°C, inelastic distortion induced by adsorption, and chemical reaction and aging of gels when exposed to water vapor.
