The materials with thermal insulating and fire-retardant properties are highly demanded for architectures to improve the energy efficiency. The applications of conventional inorganic insulating materials such as silica aerogels are restricted by their mechanical fragility and organic insulating materials are either easily ignitable or exhibit unsatisfactory thermal insulation performance. Here, we report an organic/inorganic composite aerogel with integrated double network structure, in which silica constituent homogeneously distribute in the anisotropic polyimide nanofiber aerogel matrix and strong interfacial effect is formed between two components. The integrated binary network endows the polyimide/silica composite aerogels with outstanding compressibility and flexibility even with a high inorganic content of 60%, which can withstand 500 cyclic fatigue tests at a compressive strain of 50% in the radial direction. The resulting composite aerogel exhibits a combination of outstanding insulating performance with a low thermal conductivity (21.2 mW m⁻¹ K⁻¹) and excellent resistance to a 1200°C flame without disintegration. The high-performance polyimide/silica aerogels can decrease the risk brought by the collapse of reinforced concrete structures in a fire, demonstrating great potential as efficient building materials.

建筑需要具有隔热和阻燃性能的材料以提高能源效率。传统的无机绝缘材料如二氧化硅气凝胶的应用受到其机械脆性的限制，有机绝缘材料要么容易被点燃，要么表现出不令人满意的隔热性能。在这里，我们报告了一种具有集成双网络结构的有机/无机复合气凝胶，其中二氧化硅成分均匀分布在各向异性聚酰亚胺纳米纤维气凝胶基质中，并且两种成分之间形成强界面效应。集成的二元网络赋予聚酰亚胺/二氧化硅复合气凝胶出色的可压缩性和柔韧性，即使无机物含量高达 60%，可承受500次循环疲劳试验，径向压缩应变为50%。所得复合气凝胶兼具出色的绝缘性能和低热导率（21.2 mW m^-1 K ^-1 ) 和出色的耐 1200°C 火焰而不崩解。高性能聚酰亚胺/二氧化硅气凝胶可以降低火灾中钢筋混凝土结构倒塌带来的风险，显示出作为高效建筑材料的巨大潜力。