Superstrong Lightweight Aerogel with Supercontinuous Layer by Surface Reaction

Abstract Breaking the thermal, mechanical and lightweight performance limit of aerogels has pivotal significance on thermal protection, new energy utilization, high‐temperature catalysis, structural engineering, and physics, but is severely limited by the serious discrete characteristics between grain boundary and nano‐units interfaces. Herein, a thermodynamically driven surface reaction and confined crystallization process is reported to synthesize a centimeter‐scale supercontinuous ZrO2 nanolayer on ZrO2‐SiO2 fiber aerogel surface, which significantly improved its thermal and mechanical properties with density almost unchanged (≈26 mg cm−3). Systematic structure analysis confirms that the supercontinuous layer achieves a close connection between grains and fibers through Zr─O─Si bonds. The as‐prepared aerogel exhibits record‐breaking specific strength (≈84615 N m kg−1, can support up to ≈227 272 times aerogel mass) and dynamic impact resistance (withstanding impacts up to 500 times aerogel mass and up to 200 cycling stability at 80% strain). Besides, its temperature resistance has also been greatly optimized (400 °C enhancement, stability at 1500 °C). This work will provide a new perspective for exploring the limits of lightweight, high strength, and thermal properties of solid materials.