Low-Cost Lightweight Quartz Fiber-Reinforced Hybrid Aerogel Nanocomposite for High-Temperature Oxidation Thermal Protection

Aerogels are used to achieve lightweight heat insulation in composites. To minimize cost and ensure safety, nanocomposites must be prepared without flammable or explosive solvents at room temperature and ambient-pressure drying. However, fabricating resin aerogel nanocomposites is challenging due to the tendency of porous structures to collapse owing to the complex surface tension in the multiphase system of fibers, resin particles, and solvent. A novel quartz fiber-reinforced hybrid aerogel nanocomposite is successfully prepared using the sol–gel method with self-assembly template polymerization. Two key factors in preventing aerogel collapse include the use of a cationic surfactant as a stabilizer for the initial template and as a surface tension improver during drying. The nanocomposite, with a density of 0.52 g·cm⁻³ and thermal conductivity of 0.046 W·m⁻¹·K⁻¹, exhibited a back-face temperature rise of ≈96.4 °C after a 1500 s arc-wind tunnel ablation test. The maximum ablation retreat is ≈0.26 mm. This novel nanocomposite shows potential for high-temperature protection systems in extreme oxidation environments.