Property Changes of SiO2 Aerogel on Insulation Performance under Different Time and High Temperature Condition

To study the impacts of structural change of SiO₂ aerogel on its insulating properties, the samples were treated in long time (0-12h) at 500°C, 600°C, 700°C and 800°C. The results show that with the time increased, the shrink extends in thickness, the weight loss and the density is basically unchanged under the 500°Cand 600°C. As for 700°C and 800°C, the results were treated with 0-12h, the shrink extends in thickness, the weight loss and density increases considerably. Besides, the structure and composition of SiO₂ aerogel after the different temperature treaded with 0.5h were tested. The results show that when the heat treatment temperature is between 200-800°C, the small pores in SiO₂ aerogel collapses and large pores increase, and the density is stil1 able to maintain the 1ow value due to the unbroken skeleton. When the heat temperature is between 800-1000°C, the secondary particle size increases and the rnutual integration of the secondary particles occurs, the density will be significantly increased.