Awakenable Smart-Responsive Hydrogel Armor for Adaptive Surface Protection in Marine Environments

As marine systems increasingly demand intelligent, autonomous, and long-lasting protection solutions, the design of awakenable coatings capable of dynamic response to environmental stimuli has become essential for effective corrosion resistance and antifouling performance. In this work, we report a novel awakenable hydrogel armor that integrates a dual-network hydrogel reinforced with cellulose nanofibers and embedded with pH- and photothermal-responsive ZIF-8@BTA@MPN nanocontainers. This armor-like coating exhibits both passive and active self-healing behaviors: dynamic borate ester bonds enable spontaneous recross-linking for microdamage repair, while near-infrared (NIR) irradiation triggers photothermal activation of the MPN (metal–phenolic network) shell, promoting the targeted release of the corrosion inhibitor BTA (benzotriazole) and activating shape memory-assisted crack closure. The hydrophilic hydrogel network forms a stable hydration layer, which imparts excellent antifouling and antimicrobial capabilities by resisting microbial adhesion and mitigating microbially influenced corrosion. Electrochemical impedance spectroscopy and morphological analysis confirm the coating’s strong barrier properties, sustained protective function, and long-term stability under simulated marine conditions. This work demonstrates a versatile and stimuli-responsive surface engineering strategy, where the awakenable HZC (hydrogel coatings based on ZIF-8) achieves multifunctional, durable protection through the synergy of adaptive structure, intelligent function, and environmental reactivity.