Reversible sensing of hydrophobic conductive gels induced by chitosan solvent-based solvents in complex and multi-environment conditions.

Exploring environmentally adaptive conductive hydrogels based on chitosan and deep eutectic solvent (DES) for multi-scenario applications, a novel biomass-derived conductive hydrogel, denoted as PONH@DES, was successfully synthesized through free radical polymerization. In this synthesis, Octadecyl acrylate (OA) was incorporated as a hydrophobic monomer, N-isopropyl acrylamide (NIPAM) served as a thermoresponsive component, and hydroxypropyl deacetylated chitosan (HPCS) integrated into DES system. To optimize the material performance, we systematically enhanced the interfacial compatibility between the hydrophobic polymer matrix and the DES system. The PONH@DES conductive hydrogels exhibit an extensive network of hydrogen bonds, coupled with reversible ion-dipole and dipole-dipole interactions, which collectively contribute to their distinctive electromechanical properties. The synergistic interplay of these dynamic interactions endows the hydrogels with adaptive properties, achieving an ionic conductivity of 0.06 S/cm while retaining remarkable cryogenic resilience, with operational functionality preserved even at temperatures as low as -37 °C. Furthermore, molecular dynamics simulations conducted using Materials Studio quantitatively characterized the interaction forces within the PONH@DES conductive gel network, while kinetic fitting parameters validated the experimentally observed enhancement in mechanical properties. This research presents a novel approach for safety early warning across multiple environments and is expected to hold promising application prospects in the field of flexible wearable sensors.