Octopus Skin‐Inspired Gradient Heterogeneous Coatings with Integrated Antifouling, Anticorrosion, and Abrasion Resistance

ABSTRACT Marine corrosion and biofouling represent critical challenges urgently requiring solutions in marine industrial equipment. The application of protective coatings currently stands as the most economical and effective strategy for mitigation. However, the core challenge lies in reconciling antifouling, anticorrosion, and abrasion resistance within a single‐layer coating. Inspired by the gradient structure of octopus skin, we propose a novel gradient heterogeneous network architecture that enables the integration of antifouling, anticorrosion, and abrasion resistance within a single‐layer coating. Owing to the differential reactivity of isocyanate groups and the gradual deblocking of aldimine, dicyclohexylmethane‐4,4′‐diisocyanate (HMDI) preferentially reacts with the deblocked triamine to form a highly cross‐linked polyurea network. Subsequently, the isocyanate‐terminated amphiphilic polyurea prepolymer (NAP) spontaneously migrates surfaceward, driven by its low surface energy, and concurrently undergoes cross‐linking to establish a gradient heterogeneous network architecture. Surface‐enriched NAP builds a hydration layer against biofouling, while the highly cross‐linked polyurea in bulk ensures strong adhesion (>4 MPa) and forms a dense barrier against corrosion through dense hydrogen bonding. The synergy between polyurea toughness and fluoro‑silicon lubrication further confers excellent abrasion resistance (coefficient of friction <0.15). This network design concept may open a new avenue for the development of high‐performance materials in marine engineering.