Asymmetric Janus Shear Thickening Fabric with Heat Self‐Circulating toward Impact Protection and Dynamic Thermal Management

Temperature imbalance and mechanical attacks pose severe risks to both individuals and devices in extreme environments, promoting the development of advanced protective equipment. Although intelligent thermal management and mechanically robust materials have been developed for dynamic and harsh environments, the synergistic implementation of impact/thermal coupling protection remains a challenge. This study proposes an asymmetric Janus fabric (SKMP) consisting of shear-thickening-reinforced Kevlar (SK) assembled using MXene and polyethylene glycol (PEG) thermoregulatory materials. The resulting composite fabric exhibited a remarkable tearing force of 621 N compared to 152.2 N for neat Kevlar. Notably, the composite fabric exhibits reliable bulletproof performance with a limit penetration speed of 125.79 m/s, which arises from the multiscale energy dissipation mechanism of fiber-bridge enhancement, shear thickening effect, and synergistic stress transfer. Additionally, attributed to extensive light absorption capacity and low transmission loss, SKMP demonstrates the light/heat conversion effectiveness of 12.4°C temperature difference within an extremely low MXene loading of 0.47 wt.%. Furthermore, a PEG phase-change layer is assembled to provide thermal buffering and energy storage, realizing durable thermal comfort through reasonable energy self-cycling. Therefore, this study can assist the fabrication of integrated and intelligent protection materials for future applications.