Designed VO2/ANF/PVA aerogel composite material for adaptive infrared stealth and dynamic thermal regulation

The rapid advancement of infrared detection technologies poses formidable challenges to conventional stealth materials. However, most existing infrared stealth materials rely on a single mechanism-either surface emissivity modulation or thermal conduction blocking-which limits their capacity to deliver durable and stable performance. Herein, a novel vanadium dioxide (VO₂)/aramid nanofiber (ANF)/polyvinyl alcohol (PVA) aerogel composite was successfully fabricated through a vacuum filtration and freeze-drying process. In this system, ANF and PVA form a robust support framework with exceptional mechanical properties, while VO₂ nanoparticles provide dynamic thermal camouflage properties. The resulting VO₂/ANF/PVA aerogel exhibited a low density of 0.052 ± 0.002 g/cm³, minimal shrinkage rate of 3.5 ± 0.2 %, high porosity of 96.5 ± 0.3 %, substantial compressive stress (0.169 ± 0.001 MPa at 75 % strain), and extremely low thermal conductivity of 0.048 ± 0.003 W/(m·K). Notably, the aerogel demonstrated significant infrared emissivity modulation (from 0.92 to 0.6) across a temperature range of 15–100 °C. As a thermal camouflage coating, it reduced the radiative temperature of a 70 °C object to 17.9 °C while maintaining stable performance for over 2000 s. This study achieved synergistic optimization of material structure and functionality through design of composite structures, offering valuable insights for developing advanced adaptive stealth materials.