Shape-recoverable, piezoresistive, and thermally insulated xerogels based on nanochitin-stabilized Pickering foams.

Biomass-derived porous materials are promising for various fields and preferred for sustainable development. In this work, shape-recoverable nanochitin-based xerogels with porous structure and excellent mechanical strength, thermal insulation (43.23 ± 0.17 mW/m·k) and piezoresistive properties were prepared by nanochitin-stabilized Pickering foams with chemical crosslinking for the first time through simple air-drying. At the optimized ingredients of nanochitin, surfactant (T80) and crosslinker (glutaraldehyde), the Pickering foams exhibited no significant collapse after one week, and the xerogels prepared thereof achieved a mechanical strength of 0.5-2.7 MPa at 80% strain and considerable structural stability after 100 cycles at 60% strain. Moreover, the resistance of the xerogel had a high linearity in the strain range (0-10%) and could recover to the initial value after 20 cycles. Notably, this is the first time that pure bio-based conductive xerogel has been obtained. These features make nanochitin a promising candidate for biodegradable and sustainable 3D porous materials.