Improvement of thermal stability performance of SiO2 aerogels by MgAl2O4 nanopowder

To enhance the thermal stability of SiO 2 aerogels at high temperature, this study proposes a method involving the incorporation of MgAl 2 O 4 nanoparticles into SiO 2 aerogels to improve their high-temperature stability. By comparing the performance of MgAl 2 O 4 -SiO 2 aerogel with pure SiO 2 aerogels after heat treatment at high temperatures, it is demonstrated that the MgAl 2 O 4 nanoparticles significantly enhances the thermal stability of SiO 2 aerogels at elevated temperatures while almost no effect on thermal conductivity, about 0.0312 and 0.0322 W/(m·K). The MgAl 2 O 4 -SiO 2 aerogels exhibit superior thermal stability and insulation performance compared to pure SiO 2 aerogels at temperatures exceeding 800 ℃. Notably, even after heat treatment at 1100℃, a condition that causes pure SiO 2 aerogels to nearly lose their porous structure, the MgAl 2 O 4 -SiO 2 aerogels retain a specific surface area of 81.95 m 2 /g and thermal conductivity of 0.0584 W/(m·K).