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Ambient-dried silica aerogel doped with TiO2 powder for thermal insulation

Author:
Kwon, Young-Geun, Choi, Se-Young, Kang, Eul-Son, Baek, Seung-Su
Source:
Journal of materials science 2000 v.35 no.24 pp. 6075-6079
ISSN:
0022-2461
Subject:
Fourier transform infrared spectroscopy, X-ray diffraction, ambient temperature, chemical bonding, condensation, drying, ethanol, gels, heat treatment, insulating materials, porosity, silica, surface area, titanium dioxide, washing
Abstract:
Two step-derived SiO₂ sol doped with TiO₂ powder dissolved in ethanol was prepared. After aging and washing of wet gel, surface modification with TMCS (trimethylchlorosilane) was followed to prevent additional condensation reaction during drying. Ambient-dried SiO₂-TiO₂ gel was heat-treated at various temperatures. The effects of the heat-treated temperature on the chemical bonding state of SiO₂-TiO₂ gel were investigated by means of FTIR and XRD analyses. After heat-treatment at 350 °C, crack-free SiO₂-TiO₂ gel was synthesized with density of 0.14 g/cm³, porosity of 94%, and specific surface area of 613 m²/g. Ambient-dried SiO₂-TiO₂ gel heat-treated at 350 °C exhibited thermal conductivities of 0.0136 W/m·K and 0.0284 W/m·K at room temperature and 400 °C, respectively.
Agid:
4396917