摘要
Magnesium alloys suffer from severe corrosion in chloride-containing environments, which significantly restricts their structural application. In this study, a core-shell smart nanocontainer (PHIO@ZIF-8/PST, denoted as PZS) was constructed by integrating a pH-responsive metal–organic framework reservoir with an in situ assembled poly(sodium thioctate) (PST) functional shell, and further incorporated into an epoxy matrix to develop an intelligent anticorrosion coating. The ZIF-8 core serves as an efficient loading platform for a chelating corrosion inhibitor (PHIO) and provides pH-triggered release capability, whereas the PST shell simultaneously enhances interfacial compatibility and introduces additional chemical protection. Structural analyses confirmed the successful construction of the core-shell architecture and the preservation of crystallinity after functional modification. Electrochemical and ion-release studies demonstrated that PZS nanocontainers exhibited pronounced pH-responsive behavior, enabling accelerated inhibitor release under acidic or alkaline conditions. When incorporated into the epoxy (EP) coating, PZS significantly improved the interfacial densification, reduced the defect density, and prolonged the diffusion pathways for aggressive species. Long-term electrochemical impedance spectroscopy and salt spray tests revealed that the PZS/EP coating maintained impedance values three orders of magnitude higher than that of the pristine epoxy after 28 days of immersion, indicating outstanding corrosion resistance. The enhanced performance arises from the synergistic coupling of the physical barrier reinforcement, inhibitor chelation, and in situ formation of protective Mg–PST complexes at active corrosion sites. This study provides a generalizable strategy for constructing multifunctional smart coatings for the durable protection of lightweight metal substrates.
危险品化学品经营许可证（带存储）