Synthesis and marine antifouling properties of carbazole amide derivatives with fluorescent properties and their zinc acrylate resins

Fluorescent antifouling is a method that utilizes substances fluorescent repellent effect to prevent organisms attachment and fouling. It is considered one of the directions for developing environmentally friendly marine antifouling materials. The current fluorescent antifouling materials were characterized by issues such as single functionality, unclear antifouling mechanisms, and suboptimal antifouling performance. In this study, three carbazole derivatives containing carbon–carbon double bonds were synthesized by Friedel-Crafts alkylation reaction, and a series of zinc acrylate resins containing carbazole derivative structures were further synthesized through free radical polymerization. Three carbazole derivatives were tested for their fluorescence and their growth inhibition properties against bacteria and algae. The results showed that the three carbazole derivatives not only had high fluorescence intensity, but also had good inhibitory effects on bacteria and algae, with the highest inhibition rate of 81% on algae. The fluorescence properties, algal inhibition properties and anti-algal adhesion properties of the resin were investigated. The results showed that the fluorescence intensity of the resin was enhanced with the increase of carbazole derivative content. The inhibition rate of the resin against algae was as high as 88.5%, and the anti-algal adhesion rate of the resin was improved under light conditions. Mechanistic studies showed that the resin influenced the cell wall, and the fluorescence caused the algae to prioritize photosynthesis rather than attachment and settlement. Self-polishing performance test results showed that the introduction of carbazole derivatives improved the stability of the resin. The results of the real sea antifouling test show that the resin integrates fluorescence, chemical activity and self-polishing, and has excellent antifouling performance. This provides a theoretical basis for the development of environmentally friendly marine antifouling materials.