SiC nanowire aerogel/NH 4 Cl composite as active–passive collaborative thermal protection material

Abstract Thermal protection system is a necessary component to ensure the safety of high‐speed aircraft. The development of active–passive cooperative thermal protection materials adapted to complex thermal environments remains a challenge. Herein, an emerging thermal protection material with spontaneous decomposition cooling was designed and prepared by filling inorganic salt NH 4 Cl into SiC nanowire aerogel. The ultra‐high porosity of SiC nanowire aerogel can be utilized to load inorganic salts, while its excellent thermal insulation properties provide passive thermal protection. NH 4 Cl reaches the decomposition temperature and absorbs heat to generate a “cooling interface,” which gradually moves away from the heating surface. The quartz lamp infrared thermal examination indicates that the SiC nanowire aerogel/NH 4 Cl composite could safely operate for over 350 s in a heat flow environment of 200 kW/m 2 . This work could provide the reference for the design of novel active–passive collaborative thermal protection material with spontaneous decomposition cooling.