Highly Ordered Hierarchical Orientations Enabled Antimicrobial Hydrogels with Synchronized Mechanical‐Thermal Enhancement

Abstract Polyvinyl alcohol (PVA) hydrogels present broad applications in the biomedical field due to their excellent biocompatibility, chemical stability and high hydrophilicity, but the practical utility is significantly hindered by their inherent weak mechanical strength and low thermal conductivity. This study presents an innovative strategy to prepare a PVA‐based antibacterial hydrogel with synergistically enhanced thermal conductivity and mechanical properties, which is mainly achieved by introducing Si 3 N 4 nanowires (Si 3 N 4 NWs) and constructing highly ordered hierarchical structures through directional freezing and salting‐out techniques. The resulting hydrogel exhibits an exceptional thermal conductivity of 0.82 W m −1 K −1 , nearly 1.5 times that of pure PVA hydrogel. Meanwhile, the mechanical strength of the hydrogel is significantly enhanced, with a 23‐fold increase in tensile strength (2.06 MPa) and a 2.96‐fold improvement in elongation at break (824%) relative to pure PVA hydrogel. Moreover, the Si 3 N 4 NWs not only reinforced the hydrogel but also endow it with remarkable antibacterial activity (>99% inhibition against Escherichia coli [E. Coli] and Staphylococcus aureus [S. aureus] ) and excellent cell compatibility. This multifunctional hydrogel, which combines enhanced thermal conductivity, high strength, and antimicrobial properties, has great potential for biomedical applications, including antipyretic patch, human ligament substitute and sterilization material.