Heat insulation properties of silica aerogel/glass fiber composites fabricated by press forming

Silica aerogel/glass fiber composites were fabricated by press forming of silica aerogel powders and dispersed glass fibers. Due to the nano porous structure, silica aerogel showed low gas thermal conductivity and solid thermal conductivity. By adding the glass fibers, the strength of the composites was improved but the heat insulation property was deteriorated. The thermal conductivities of the composites with 20 wt.% glass fibers at 300 degrees C and 600 degrees C were 0.025 W/(m K) and 0.030 W/(m K), respectively. As opacifier, the addition of TiO2 decreased the radiative thermal conductivity abruptly, especially at high temperatures. At 700 degrees C, it decreased from 0.041 W/(m K) to 0.030 W/(m K) after 20 wt.% TiO2 powders were added. (C) 2012 Elsevier B.V. All rights reserved.