Fabrication of Al2O3 aerogel-SiO2 fiber composite with enhanced thermal insulation and high heat resistance

The thermal-resistance Al2O3 aerogels and Al2O3 aerogel-SiO2 fiber composite by using inorganic aluminum salt as the precursor were synthesized by the sol-gel process. The method was straightforward, inexpensive, and safe. Furthermore, it was found that the as-prepared Al2O3 aerogel had high crystal phase transition temperature. As the heat treatment temperature increased to 900 degrees C, the crystal phase transition from gamma-AlOOH to gamma-Al2O3 occurred within the Al2O3 aerogel. Meanwhile, the Al2O3 aerogel-SiO2 fiber composite exhibited high Young's modulus of tensile strength up to 6.59MPa and low thermal conductivity at 35 degrees C (0.028W/(mK)) and high temperature of 600 degrees C (0.033W/(mK)). In addition, the results indicated that the Al2O3 aerogel-SiO2 fiber composite had the moderate hydrophobic property as well as mechanical property.