A pH-responsive smart anticorrosion coating based on CoFe2O4 nanocontainers with robustness and high inhibitor-loading capacity

Inhibitor-loading nanocontainers are considered as promising materials for smart anticorrosion coatings due to their potential to realize stimuli-responsive self-diagnose and self-healing. However, unsatisfying inhibitor-loading capacity and robustness as well as elaborated design restrict their up-scaling and application in long-term corrosion protection. In this work, cobalt ferrite (CoFe 2 O 4 , CFO) nanospheres with nanoporous structure and robustness are utilized as smart nanocontainers, which are successively coated with polyethyleneimine (PEI), polyacrylic acid sodium (PAAS) and imidazoline quaternary amination salt (IQAS) via electrostatic layer-by-layer assembly (CFO@PEI/PAAS/IQAS). Subsequently, the CFO@PEI/PAAS/IQAS is incorporated with styrene-ethylene-butylene-styrene thermoplastic elastomer (SEBS), forming a smart anticorrosion coating (CFO@PEI/PAAS/IQAS composite coating). The porous structure together with the robustness of CFO facilitate the high inhibitor-loading capacity and the mechanical durability of the coating. Moreover, the CFO@PEI/PAAS/IQAS composite coating exhibits outstanding corrosion resistance and pH-responsive self-healing performance for scratches. This kind of pH-responsive nanocontainers with facile preparation method provides a broad application potential for the next generation of smart anticorrosion coatings.