Effect of Heat-Treatment on the Microstructure and Properties of SiO2-TiO2 Aerogels Synthesized via Supercritical Drying
| Autor: | Lin Xu, Jian Feng, Yan Qing Qin, Yong Gang Jiang, Jun Zong Feng |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Anatase
Materials science Nanoporous Mechanical Engineering Supercritical drying 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences 0104 chemical sciences Thermal conductivity Mechanics of Materials Rutile Phase (matter) Specific surface area General Materials Science Composite material 0210 nano-technology |
| Zdroj: | Materials Science Forum. 848:770-776 |
| ISSN: | 1662-9752 |
| DOI: | 10.4028/www.scientific.net/msf.848.770 |
| Popis: | Monolithic SiO2-TiO2 aerogels were prepared via supercritical drying using tetraethoxysilane and tetrabutyltitanate as precursors and ethanol as solvent. Influence of the heat-treatment on the microstructure and properties of SiO2-TiO2 aerogels were investigated in detail. The results showed that the as-prepared SiO2-TiO2 aerogels had low densities, high specific surface areas, small average pore diameters, and three-dimensional nanoporous structures. The anatase TiO2 phase of SiO2-TiO2 aerogels could form during supercritical drying process, and the transition to rutile TiO2 phase occurred after experiencing 1200°C for 2 h. SiO2-TiO2 aerogels containing 30 wt% TiO2 (ST3) still presented relatively high specific surface area of 451 m2/g even they undergo the treatment of 1000°C for 2 h. And the SEM images indicated that the agglomerated particles derived from ST3 appeared gradually to some extent. The glassy luster of ST3 heat-treated at 1200°C for 2 h illuminates SiO2 started to vitrify. Besides, the thermal conductivity of ST3 at room temperature is up to 0.03257 W·m-1·K-1. |
| Databáze: | OpenAIRE |
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