MXene/Ag doped hydrated-salt hydrogels with excellent thermal/light energy storage, strain sensing and photothermal antibacterial performances for intelligent human healthcare

Developing multifunctional phase change materials (PCMs) with room-temperature flexibility, moderate photothermal therapy, and antibacterial activity still remains an enormous challenge. In this study, phase change hydrated salts (Na2SO4·10H2O, SSD) were packaged into a sodium alginate (SA) and polyacrylamide (PAM) double-network hydrogel with the addition of MXene@Ag (MA) nanosheets. The PAM/SA/SSD/MA hydrogels showed high enthalpy (176.0 J/g) and high size retention. Besides, the hydrogel-based sensor exhibited a wide strain sensing range, good sensitivity, and fatigue resistance (800 tensile cycles) due to the robust double-network and electrical MXene@Ag nanosheets, which can monitor subtle and intense human motion. More importantly, benefiting from the synergetic photothermal effect of MXene and Ag, the hydrogel exhibited good photo-thermal energy storage and antibacterial performances, which can be applied in moderate photo-thermal therapy to relieve pain. This research provides a potential avenue for multifunctional phase change hydrogels toward wearable thermal management and human healthcare devices.