Tough and Conductive Dual Physically Cross-Linked\nHydrogels for Wearable Sensors

Abstract

It\nis imperative to achieve excellent mechanical and electrical\nproperties in a single hydrogel. Herein, based on hydrogen bonds and\nhydrophobic associations, poly­(<i>N</i>-hydroxymethyl acrylamide)\nhydrophobic association hydrogels (PHMA HA gels) with dual physically\ncross-linked networks were prepared through micellar copolymerization\nof HMA and stearyl methacrylate (C₁₈) under the action\nof a surfactant and sodium chloride (NaCl). Under optimal conditions,\nPHMA HA gels could achieve excellent tensile strength (1.09 MPa) and\nhigh toughness (1509 J/m²). Additionally, PHMA HA gels\nexhibited outstanding self-recovery and self-healing properties as\nwell as high conductivity, and they could serve as sensors of strain\nand pressure to monitor human movements. It is believed that PHMA\nHA gels with integrated high performances have broad application prospects\nin wearable electronics.