Corrosion Resistance and Antifouling Bioinspired Coating with Doped Polyaniline and TO@CA Self-Healing Nanocapsules

In this study, an integrative bioinspired coating system for antifouling and corrosion resistance was investigated, in which self-healing nanocapsules (tung oil calcium alginate, TO@CA), doped polyaniline and nano-titanium dioxide nanocomposites (SPAn–TiO₂) and a biostructure metal surface were combined. The antifouling property of the bioinspired coating resulted from the synergistic antifouling effect of nano-TiO₂ and acid-doped polyaniline in SPAn–TiO₂. The protonated nitrogen with a positive charge in SPAn–TiO₂ and the intrinsic bactericidal property of nano-TiO₂ could damage negatively charged single-celled chlorella, endowing the composite coating with good antifouling performance (less algae attached on the surfaces after a 90-day antifouling test and a conductivity test). The composite bioinspired coating had excellent corrosion resistance, which was due to the good synergistic anticorrosion barrier effect of SPAn–TiO₂ with TO@CA nanocapsules and the repairing ability of microcracks of TO@CA nanocapsules during the corrosion process. The bioinspired coating with 2 wt% SPAn–TiO₂ and 2 wt% TO@CA nanocapsules exhibited a better adhesion, corrosion resistance and antifouling performance than the other coatings did.