Sub-zero temperature self-healing anticorrosion coatings based on dynamic reversible imine and metal coordination bonds

Abstract

Anticorrosive coatings have been widely studied as a promising strategy to prevent or delay metal corrosion, but their effectiveness is limited by coating degradation. Self-healing coatings can mitigate damage through autonomous repair, thereby significantly extending service lifetime even under harsh conditions. Herein, we report an innovative self-healing anticorrosion coating system based on a novel dual-dynamic-bond network combining reversible imine and Zn²⁺ coordination bonds. The designed PDMS-HQA-Znₓ system achieve breakthrough autonomous self-healing at sub-zero temperatures (−10 °C) without external stimuli, while maintaining excellent mechanical properties (0.11 MPa tensile strength, 131 % strain). The unique metal-ligand coordination architecture enables: (1) temperature-independent self-healing through dynamic bond recombination, (2) tunable mechanical performance via Zn²⁺ content adjustment, and (3) excellent corrosion protection with low corrosion current density (7.6 × 10⁻⁶ A·cm⁻² after 72 h in 3.5 wt. % NaCl). This work establishes a new design principle for next-generation protective coatings that maintain functionality under extreme conditions.