Sandwich-Structured Thermal Responsive Composites with Anisotropic Deformation for Ultra-High Temperature Sensing and Protection Applications

The development of responsive thermal protection materials to endure an extreme thermal environment remains a critical challenge in the aerospace and fire protection sectors. Herein, expandable vermiculite (EV) and carbon fiber were employed as a thermal response filler and reinforcing filler in silicone rubbers to fabricate a thermal protection material with self-adaptiveness and thermal responsiveness under plasma ablation conditions. A sandwich-structured thermal responsive composite that integrates directional deformability with robust high-temperature resistance was proposed. The architecture was constructed by using a restriction-expansion-restriction (R-E-R) configuration, which consists of an EV-filled silicone rubber core constrained by carbon fiber-reinforced outer layers. The design enables anisotropic deformation under the influence of thermal stimuli, exhibiting substantial longitudinal expansion while maintaining a horizontal stability. Woven carbon fiber fabric was embedded to enhance directional reinforcement and guide the deformation behavior. As a result, the horizontal expansion ratio was suppressed to around 1% while the longitudinal expansion ratio reached nearly 70%. Upon exposure to a heat flux of 2 MW·m–2, the composite exhibited adaptive actuation and excellent thermal insulation performance. The maximum back temperature of a 4 mm-thick sample reached 240 °C. These multifunctional materials offer promising solutions for self-sealing, adaptive gap-filling, and high temperature thermal insulation that exhibit promising application in the thermal protection sectors.