Self-Releasing Vanillin: An Eco-Friendly Self-Polishing Coating Designed for Marine Antifouling

Biological fouling will cause severe damage to the functionality of marine underwater facilities, shorten their service life, impede their normal operation, and trigger a biological invasion event. The traditional marine antifouling coatings release heavy metal elements, which cause harm to the marine environment. To overcome this issue, a self-polishing antifouling resin based on vanillin methacrylate (VMA) was prepared via the free radical polymerization method. In seawater, the VMA-based coatings achieve self-polishing through the hydrolysis of the phenolic ester group. The hydrolysis mechanism of VMA was calculated using density functional theory by Cp2k software, and the results show that VMA achieves one-step hydrolysis by the S_N2 mechanism. It exhibited antibacterial and environmentally friendly antifouling properties by releasing vanillin, which is a natural antifouling active substance. The antibacterial, diatom adhesion inhibition, and the 9-month marine field test demonstrated the excellent antifouling performance of VMA-based coatings. It provides a novel concept for environmentally friendly self-polishing coatings and has a promising application prospect.