Biodegradable Dual‐Network Chitosan Composite Aerogel by In Situ Mineralization for Substituting Petroleum‐Based Counterparts

With the growing concerns over energy consumption and environmental pollution, bio-based aerogels such as chitosan have garnered a significant interest. However, chitosan aerogels suffer from the inherent drawbacks including high flammability, unsatisfactory thermal insulation and inadequate reversible compressible resilience, while the existing strategies struggle to achieve the synergistic enhancement of multiple properties. Herein, a dual-network structural strategy is proposed to prepare a high-performance chitosan composite aerogel by an in situ mineralization growth of periodic phosphorus, nitrogen-containing organosilica network within chitosan matrix through hydrolytic polycondensation. The composite aerogel shows an ultralow thermal conductivity of 22.4 mW·m^-1·K^-1, a high limiting oxygen index of 38.1%, and good reversible compressible resilience. Simultaneously, it achieves the complete soil biodegradation within 15 days. It retains over 85% of initial performance after 20 recycling cycles, benefiting from the hydrogen bonding interactions between the dual-network. This work provides a novel strategic approach for preparing high-performance bio-based aerogels to replace the conventional petroleum-based thermal insulation materials, thereby contributing to a carbon neutrality goal.