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

• Published in: Journal of porous materials 2019-08, Vol.26 (4), p.1027-1034
• Main Authors: Wen, Shangyan, Ren, Hongbo, Zhu, Jiayi, Bi, Yutie, Zhang, Lin
• Format: Article
• Language: English
• Subjects: Aerogels; Aluminum oxide; Catalysis; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Fiber composites; Heat resistance; Heat treatment; High temperature; Modulus of elasticity; Phase transitions; Physical Chemistry; Silicon dioxide; Sol-gel processes; Thermal conductivity; Thermal insulation; Thermal resistance; Transition temperature; Transitional aluminas
• ISSN: 1380-2224; 1573-4854
• DOI: 10.1007/s10934-018-0700-6

The thermal-resistance Al 2 O 3 aerogels and Al 2 O 3 aerogel-SiO 2 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 Al 2 O 3 aerogel had high crystal phase transition temperature. As the heat treatment temperature increased to 900 °C, the crystal phase transition from γ-AlOOH to γ-Al 2 O 3 occurred within the Al 2 O 3 aerogel. Meanwhile, the Al 2 O 3 aerogel-SiO 2 fiber composite exhibited high Young’s modulus of tensile strength up to 6.59 MPa and low thermal conductivity at 35 °C (0.028 W/(m K)) and high temperature of 600 °C (0.033 W/(m K)). In addition, the results indicated that the Al 2 O 3 aerogel-SiO 2 fiber composite had the moderate hydrophobic property as well as mechanical property.