Superelastic Carbonaceous Nanofibrous Aerogel Enables High Pressure-Sensitivity, Thermal Insulation and Photothermal Properties

Carbonaceous aerogels attract extensive research interest due to their impressive physical properties such as high porosity, high electrical conductivity, low thermal conductivity, and low density. However, the low durability of the aerogels under compression is a concern due to the intrinsically weakness. In this work, superelastic, multimodal porous, carbonaceous nanofibrous aerogel (CAs) were prepared by carbonizing chitin aerogels (ChAs). The ChAs were prepared and structurally optimized by combining progressive typical dissolution–regeneration, solvent exchange with 50 wt% tert -butanol and lyophilization. The CAs exhibited remarkable elasticity and stability under compression, even under extreme temperatures. After the CAs had been subjected to loading-and-unloading cycle under the compressive strain ( ɛ ) of 50%, the CAs exhibited a very low energy-loss coefficient (0.15) at the first cycle. Moreover, the CAs maintained structural integrity with little deterioration of mechanical properties after 1000 cycles. The structural stability and the superelasticity conferred the CAs a fast and accurate piezoresistive response, which renders it potential for the fabrication of pressure sensor with a high gauge factor (GF, 14.24) under low ɛ (less than 2%). Furthermore, the biomass derived cost-efficient CAs demonstrated excellent thermal insulation and high photothermal-conversion efficiency of solar energy (96.4%)