Self-Cross-Linked Carbon-Nanofiber-Based Aerogels for Infrared Stealth under Extreme Conditions

With the rapid advancement of infrared detection technologies, the demand for high-performance infrared stealth materials capable of operating under extreme conditions has become urgent. Traditional low-emissivity coatings offer some degree of infrared stealth; however, they suffer from thermal shock and uneven heat distribution when exposed to harsh environments. This highlights the critical need to develop materials that not only ensure infrared stealth performance but also possess exceptional mechanical strength and thermal stability under extreme conditions. Here, inspired by the distinctive thermoregulatory layered skin structure of desert lizards, the thermomechanically stable and thermally insulating carbon nanofiber aerogels with a curled, interlocked, and self-cross-linked fibrous structure were designed through humidity-induced phase separation and self-cross-linking strategies. The aerogels demonstrate resilience with over 96% stress retention after 1000 cycles, with an energy dissipation factor as low as 0.31. Moreover, they maintain superelasticity under extreme conditions, offering exceptional mechanical stability and thermal shock resistance across temperatures from -50 to 200 degrees C. Furthermore, the aerogels boast a low thermal conductivity of 0.030 W<middle dot>m-1<middle dot>K-1. Drawing additional inspiration from the highly reflective scale structure of the desert lizard's epidermis, we designed aluminum foil-carbon composite aerogels by affixing high-reflectivity aluminum foil papers to the surface of the carbon aerogels, resulting in a composite with low infrared emissivity (0.24). In both extreme-cold (-196 degrees C) and high-temperature (400 degrees C) environments, the composite aerogels exhibit outstanding infrared stealth performance, fully illustrating their potential for use in demanding conditions.