The synthesis of high-strength monolithic Al₂O₃-SiO₂aerogels through increased solid content and high-temperature calcination

High-strength Al2O3-SiO2 aerogels were synthesized by simultaneously increasing the solid content and high-temperature calcination. The effects of solid content and high-temperature calcination on mechanical properties, thermal conductivity, and microstructure of Al2O3-SiO2 aerogels were studied. The increase in solid content can improve the mechanical properties of aerogels. High-temperature calcination can further improve mechanical properties and reduce thermal conductivity. Finally, we fabricated a high-strength monolithic Al2O3-SiO2 aerogel with a high Young's modulus of 127.45 MPa, room temperature thermal conductivity of 29.15 mW·m-1·K-1, and density of 252 mg·cm-3. This work is significant to the adhibition of Al2O3-SiO2 aerogels as high-strength thermal insulation materials.