Multi-Scale Synergistic Networks Enable Wood-Derived Carbon Aerogels With High Compressibility and Temperature...

Carbon aerogels enable exceptional thermal insulation at extreme temperatures, yet their inherent brittleness and lack of mechanical resilience constrain practical load-bearing applications. To address this strength-resilience trade-off, we report a sustainable alternative: A wood-derived carbon aerogel that turns ordinary wood into a carbon material with high-temperature thermal insulation capability under inert atmospheres. This is achieved by using a delignified wood carbon sponge scaffold infiltrated with phenolic carbon aerogels of variably controlled particle sizes (tunable via resorcinol/chitosan ratio adjustment). The natural cellulose skeleton provides elastic buckling capacity, while the multisized phenolic fillers reinforce cell walls and inhibit crack propagation, forming a synergistic load-bearing network. The WCS-CA50 sample exhibits a room-temperature thermal conductivity of 0.037 W/(m·K), a thermal conductivity of 0.13 W/(m·K) at 1100°C, and a compressive stress of 0.517 MPa at 50% strain, indicating a balanced combination of thermal insulation and mechanical performance. This strategy utilizes renewable wood biomass as the primary structural matrix, offering a renewable route to fabricating carbon-based thermal protection systems without reliance on synthetic fiber reinforcements.