Adaptive Infrared Stealth Aerogel Based on Temperature-Responsive Variable Emissivity and Shape Memory Thermal Isolation Effects

Traditional infrared stealth technology focuses on fixed infrared stealth materials that reduce surface infrared emissivity and heat insulation, making it difficult to meet the needs of complex environments. Conventional stealth materials do not work well for equipment that is prone to high temperatures, so the development of intelligent infrared stealth materials with excellent thermal insulation properties has broad application prospects. Here, we first prepared an aerogel material with shape memory effect and tunable emissivity by selecting polyethylene glycol diacrylate (PEGDA), chitosan (CS), and vanadium dioxide (VO2). The resulting aerogel has a low heat distortion temperature (about 70 °C) and excellent mechanical properties (more than 85% stress effect even after 100 compression cycles), significant deformation effect (morphology change rate of about 28%), and emissivity transition characteristics (from 0.921 to 0.596). Importantly, as the aerogel is heated back to its original fluffy structure, it enhances its thermal insulation effect and the emissivity of the VO2 coating gradually decreases. As expected, after reaching thermal equilibrium at 100 °C, the aerogel not only recovers its original structure but also maintains its surface temperature at about 40 °C, and its adaptive surface IR emissivity decreases to provide a proper IR stealth effect.