Composite of SiO2 and Hydrogel Having Microphase Separated Structure: Physical Properties Dependence on pH |
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Authors: | In-Seok Oh No-Hyung Park Jong-Heon Park Sung-Jae Choi Kyung-Do Suh |
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Affiliation: | 1. Division of Chemical Engineering , College of Engineering Hanyang University , Seoul, 133-791, Korea;2. Department of Chemical Engineering , Samchok National University Samchok , Kangwondo, 245-080, Korea;3. Department of Chemical Industry , Dankook University Cheon-An , Chungnam, 330-714, Korea |
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Abstract: | Abstract Organic-inorganic composite gel was prepared by using PEG-modified urethane acrylate (PMUA) gel and tetraethoxysilane (TEOS). PMUA gel was prepared by the phase-inversion emulsion polymerization of PMUA emulsion. The gelation of PMUA emulsion using this method enables PMUA gel to swell with H2O, TEOS, and ethanol. Hydrolysis and condensation reaction rates of the sol-gel process are strongly influenced by the pH controlled by catalysts such as HCl and NH4OH. Additionally, the morphology on the cross section of composite and the amount of silica ingredient incorporated into the composite gel were dependent on solvent, the molar ratio of H2O to TEOS, as well as the pH value. As the silica content increased, due to hydrogen bonds interacting between PMUA gel and SiO2, particles, the tensile strength of composites considerably increased, whereas the elongation at break decreased. The incorporation of silica ingredient in PMUA gel/silica composites was verified with FTIR/ATR and SEM. The amount of the silica component in the composite was indirectly investigated by using TGA thermal analysis. |
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Keywords: | Sol-Gel Process Hydrogel pH Hydrophilic Domain Depolymerization |
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