Characterization of SiO₂ Aerogel/SiO₂ Fiber Composites Prepared by Sol-Gel Method

Abstract:

Quartz fiber composites filled with nanosized SiO₂ were prepared by sol-gel method with vacuum impregnation , supercritical drying and surface modification. The silica sol for vacuum impregnated were made from tetraethyl orthosilicate (TEOS), anhydrous ethanol, water and acid catalyst as the starting materials. The water adsorption rate, apparent porosity and electrical properties of composites were investigated by means of archimedes method and waveguide method while the surface area and pore size of the aerogel samples were tested by BET, the mechanism of hydrophobicity was also discussed. The results showed that the moisture absorption rate of products was decreased to 1.21% from 17.36% that without filled with nanosized SiO₂, with a decreasing range of 93%. Additional coating could make the rate even as low as 0.052%.The dielectric constant had no significant change while the loss tangent decreased from 3.1╳10^-3 to 1.4╳10^-3,with a decreasing range of 51.2%.

• Periodical: Key Engineering Materials (Volume 697)
• Pages: 409-413
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.697.409
• Online since: July 2016
• Authors: P. Zhai*, Xiao Feng Duan, Qing Li Zhang, Hong Sheng Wang, Hong Hao Cheng, Xun Hu Zhang
• Keywords: Aerogel, Dielectric Properties, Moisture Absorption Rate, SiO₂ Fiber Reinforced SiO₂ Ceramic Composites

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