Transparent, Flexible, Responsive Switching “Delayed” Amphiphilic Coatings Designed on the Basis of the Full-Cycle Antifouling Strategy

Abstract

Marine fouling on the surface of ships and equipment not only creates problems of enhanced resistance to navigation and increased energy consumption but also leads to unclear vision and inaccurate data collection. Antifouling coatings to resist fouling are effective, but it is difficult to achieve long-lasting fouling protection with a single interface state. Switching the status of the interface by intelligent response is a reasonable way to achieve full-cycle efficient antifouling. In this study, the hydrophobic and active antifouling interface in the initial state was achieved by adopting the fluorine-containing group and the natural extract (citronellol) as the antifouling active site. The switching of the interface relies on silanes, which respond to the generation of zwitterions in a seawater environment. Eventually, the interface switched from the hydrophobic state to the amphiphilic state with delayed formation, which achieved continued antifouling. Based on the full-cycle antifouling concept, the combination of low surface energy and antifouling active ingredients in the initial state sustainably switched surfaces in the midterm (free radicals generated during the hydrolysis process), and amphiphilic interfaces formed by “delays” produced an antifouling effect from the initial stage to the subsequent stage. The excellent antifouling activity (bacterial and diatom attachment inhibition by over 90% and significantly reduced mussel adhesion force), optical transparency, and flexibility of these coatings indicate the potential for the application of antifouling coatings prepared from hyperbranched silicone-based resins; they can also be used for data extraction sensors, underwater probes, marine photovoltaics, and other areas where transparency is required.