A “two birds one stone” strategy for self-healing marine coatings with antifouling and anticorrosion properties

Metal materials in marine environments face harsh conditions, with damage from marine gravel significantly reducing their performance. One solution is self-healing integrally antifouling and anticorrosion coatings (SIAAC) made from epoxy resin (EP). However, balancing these properties is challenging, often prioritizing one at the expense of the other. To address this, a 2D nano-fillers (GB@MMT) were prepared by loading benzimidazole (BIA) with antifouling and anticorrosion properties onto montmorillonite (MMT) via cation exchange. Dispersed in silicone-grafted EP, a composite coating (SiEP-3GB@MMT) has been developed. SiEP-3GB@MMT, with excellent antifouling property and high anti-protein adsorption performance, has a surface energy of 17.05 mJ/m², similar to silicone. The maximum antibacterial and algal inhibition rates are 89.3 % and 98.4 %, respectively. The 2D layer's shielding effect and corrosion inhibitor enable long-term immersion without corrosion. GB@MMT significantly improves the coating's anticorrosion and adhesion. The |Z|_0.01Hz of SiEP-3GB@MMT remained at 9.00 × 10⁸ Ω·cm² after being immersed in a 3.5 wt% NaCl solution for 30 d. The artificial defect forms the stable “scar” after being immersed, achieving self-healing. This work offers a novel perspective on designing the SIAAC using EP.