Low mechanical-hysteresis conductive hydrogel conferred by chitosan bridging and MXene nanoconfined mechanism

Abstract

Large mechanical hysteresis, stemming from the inherent viscoelasticity of the hydrogel networks, seriously affected its service life and application scope. Herein, we introduced a synergistic approach combining MXene nanoconfinement and bridging effect to produce hydrogels with low mechanical hysteresis. The introduced MXene was able to provide an effective nanoconfined effect on the polymerization of acrylamide monomers. By synergizing with the bridging effect—facilitated by strong interactions between chitosan-grafted polyacrylamide and solvent molecules to accelerate stress transfer—we successfully developed a MXene-reinforced conductive hydrogel with mechanical hysteresis as low as 3.17 %. Additionally, the strong electrostatic interactions between the chitosan and MXene further affiliate the dispersion of MXene within the hydrogel. The resulting MXene-reinforced conductive hydrogel demonstrated remarkable temperature sensitivity (TCR = −1.42 %/°C), making it suitable to be used as a health monitoring device. These findings opened up new perspectives for the further expansion of MXene and beyond.