Chitosan-based responsive self-healing waterborne anti-corrosion coating incorporating conductive polymer hydrogel...

In the nervous system, neuronal action potentials induced by stimulation reach axon terminals, triggering neurotransmitter release and propagating signals across the neural network. Inspired by neural signal transduction mechanisms, this study designs a responsive self-healing coating synergizing active and passive corrosion protection. A conductive polyaniline-grafted chitosan hydrogel network is integrated into a waterborne epoxy resin matrix via hydrogel coating technology. The inhibitor 2-mercaptobenzothiazole (MBT) is vacuum-encapsulated and deposited onto 304 stainless steel by spin-coating. Combined with first-principles calculations, it was demonstrated that this network rapidly responds to the local pH decrease caused by corrosion near metastable pitting sites on the metal, promptly releasing the vacuum-encapsulated MBT inhibitor. Vacuum-encapsulated MBT is rapidly released by the network in response to local pH reduction caused by corrosion near metastable pits, and the inhibitor is swiftly transported through its channels, enabling the coating to exhibit superior corrosion resistance during long-term immersion in 3.5 wt% NaCl solution. Electrochemical impedance spectroscopy (EIS) confirms exceptional corrosion resistance, with |Z|_0.01Hz maintained at 7.54 × 10⁸ Ω·cm² after 35 days. Scratch tests demonstrate effective self-healing, as |Z|_0.01Hz increases to 4.97 × 10⁷ Ω·cm² within 14 h. The value is about two orders of magnitude higher than that of the blank coating. Neural network signal transduction principles establish innovative frameworks for advancing metallic protection methodologies.