SiO₂ aerogel-embedded carbon foam composite with Co-Enhanced thermal insulation and mechanical properties

Herein, we report the design and preparation of a carbon foam composite with the addition of SiO₂ aerogel, aimed to obtain a novel thermal insulation material. SiO₂ aerogel was formed via a sol-gel process and then mixed with the mesophase pitch, followed by further foaming and carbonization process to synthesize the SiO₂ aerogel/carbon foam composite. The effects of SiO₂ aerogel content on the morphology and performance of composite product were studied to understand the relationship between the microstructure and the thermal insulation performance and mechanical strength of the composite. The results showed that the addition of SiO₂ aerogel had a significantly effect on the microstructure of the pore cells. The composite with SiO₂ aerogel addition showed better thermal insulation performance as compared with the pristine carbon foam; and the composite with 11 wt % SiO₂ aerogel content possessed a minimum thermal conductivity of 0.254 W/m·K. Meanwhile, the mechanical strength of the resultant composite was found co-enhanced with the addition of SiO₂ aerogel. Our study paves a new avenue to realize the simultaneous enhancement of thermal insulation performance and mechanical strength of carbon foam.