Thermal Insulation and Moisture Resistance of High-Performance Silicon Aerogel Composite Foam Ceramic and Foam Glass

With the globalization of green energy-saving buildings, improving the thermal insulation performance of building exterior walls has become an important breakthrough in reducing building energy consumption. And the building envelope to improve insulation properties as a starting point for energy saving. Herein, a new type of material with excellent heat insulation and moisture resistance is developed. Hence, the sol–gel process, high-pressure impregnation as well as supercritical drying are used to synthesize foam ceramic composite SiO₂ aerogel (FC@SA) and foam glass composite SiO₂ aerogel (FG@SA) materials. While maintaining the porous nanostructure of the aerogel, the aerogel is filled and embedded in the pores of the foamed material by a high-pressure impregnation method. The thermal conductivity of FC@SA and FG@SA are, respectively, 0.04159 and 0.04424 W (m K)⁻¹ at 25 °C, which are 36.02% and 23.72% lower than foam ceramic and foam glass. FC@SA reached water saturation (49%) in 48 h, while it took 72 h for FG@SA to reach water saturation (38%). Therefore, the composite building material prepared by embedding nano-aerogel into ceramic foam and foam glass has great potential in the insulation material of building fence structures.