Antifouling and fouling-release coatings with polysaccharides: a nature-based solution to a marine challenge.

Marine biofouling presents unique challenges in various industrial applications. This has historically been addressed using antifouling or fouling-release coatings. However, issues with the leaching of active or non-active components with non-target toxicity have resulted in increased regulatory scrutiny of these solutions. Natural polysaccharide-based coatings have emerged as an alternative as they contain many chemical functional groups that can enhance fouling-release/antifouling properties. In this review, polysaccharide structural properties, such as crystallinity and ionic character, are discussed with respect to functional coatings properties, such as wettability and antifouling performance. The limitations of polysaccharide antifouling performance in environments of high silt and salt are also noted. Mitigation of these challenges by hydrophobic chemical modifications - amphiphilic polysaccharides - are explored as the frontier for high-performance coatings development. Recommendations are provided for future coatings development to better reflect real-world conditions, including using polysaccharides in commercial resin technologies and more extensive field test validation.