Achieving anti-corrosion and anti-biofouling dual-function self-healing coating by natural carrier attapulgite loading with 2-Undecylimidazoline

In the marine environment, the protective coatings face serious corrosion and biofouling problem, limitations, and challenges that made self-healing coatings unable to perform both anti-corrosion and anti-biofouling dual-function at the same time. Here we constructed the corrosion resistance and anti-biofouling self-healing coating by integrating nano-containers into the coating matrix, the 2-Undecylimidazoline (ULM) acted as a corrosion inhibitor and anti-biofouling dual-functional agent which was loaded on the natural container attapulgite (ATP). To obtain high healing efficiency, a fluidity-driven self-healing silicone oil coating was thickened by fibrous ATP to enhance its stability, which played a key role in the self-healing and long-term corrosion resistance. The self-healing time of ULM@ATP reinforced oil coating was 4 s at least in the air and up to 30 s in the 1 M HCl solution. Meanwhile, the ULM@ATP can significantly enhance the corrosion resistance of the self-healing coating, with the best effect achieved when the content of ULM@ATP was 5 wt.%. The impedance modulus of ULM@ATP-2 still reached 1.62 × 108 Ω cm2 after 480 immersion in 3.5 wt.% NaCl solution, which is 3 orders of magnitude high than pure Oil coating (2.17 × 105 Ω cm2). The restructure of the ATP network and the release of ULM could largely inhibit the corrosion of metal. The continuous open circuit potential of the composite coating performed the potentially infinite self-healing capacity. The self-healing performances of the composite coating in strong acid and base solutions exhibited high environmental suitability. This anti-corrosion and anti-biofouling (the surface coverage of adhered chlorella decreased 96.88%) dual-function strategy of self-healing coatings could be also realized by many other porous nano-materials or function modifications. The self-healing performances of the composite coating in strong acid and base solutions exhibited high environmental suitability. This anti-corrosion and anti-biofouling dual-function strategy of self-healing coatings could be also realized by many other porous nano-materials or function modifications. The rapid response self-healing coating possessed anti-biofouling and active self-healing functions and showed wide application under more service environments.