A Rapidly Self-Healing Composite Hydrogel with Exceptional Impact Resistance Enabled by Synergistic Noncovalent Networks

Impact-resistant materials are vital for protection but often lack the combination of flexibility, strength, and reusability. Herein, we developed a self-healing hydrogel composite engineered through a hierarchical noncovalent strategy. By hydrophobic associations, electrostatic interactions, and hydrogen bonds in synergy, the material circumvents the traditional trade-off between mechanical strength and self-healing. The resulting composite exhibits exceptional mechanical performance, including ultrahigh tensile strength of 40 MPa, exceptional toughness of 177 MJ m^–3, and outstanding puncture resistance of 478 N. Meanwhile, the inclusion of PDAP provided the hydrogel with rapid, on-demand self-healing properties via the photothermal effect under NIR irradiation, achieving an efficiency exceeding 99% within 15 min. Furthermore, this hydrogel exhibits strain-dependent ionic conductivity and NIR-induced conductivity recovery. By merging the sensing and reparable capabilities of hydrogels with their robust impact and puncture resistance, this innovative material paves the way for advanced protective applications, such as high-performance sportswear and next-generation ballistic armor.