A comprehensive review of next-generation alginate derivatives for eco-friendly corrosion resistance and biofouling prevention

Alginate, renowned for its exceptional properties, including biocompatibility, biodegradability, surface functionalization, and gel-forming ability, has emerged as a highly effective corrosion-resistant and antifouling material for sustainable applications in aqueous environments. Alginate-based composites exhibit intrinsic self-healing capabilities due to their unique molecular structure, which encapsulates exposed metal surfaces and mitigates further corrosion. Consequently, alginate-based coatings extend the longevity of metal structures while reducing the frequency of maintenance, making them particularly advantageous for long-term use in harsh environments. Previously, some reviews highlighted the general applications of biopolymers; the present report focuses uniquely on alginate and its derivatives as sustainable corrosion inhibitors for aqueous and coating phase applications. The next-generation designs of effective alginate derivatives have been surveyed and proposed by structural modification, grafting, and hybrid nanocomposite integration. This review also highlights the roles of alginate-based coatings in enhancing antifouling performance. Following an overview of fundamental corrosion-resistance mechanisms, we delve into the interfacial and surface properties of alginate-based coatings, including their molecular architecture, amphiphilic characteristics, and key attributes that enhance their effectiveness across various industrial applications, such as ship hulls, undersea infrastructure, and maritime equipment. Additionally, we critically assess the latest research developments, evaluation methodologies, and comparative performance analyses against conventional coatings. Finally, we highlight alginate-based coatings’ advantages, challenges, and future directions for corrosion protection and antifouling applications. The comprehensive review bridges between materials engineering, corrosion science, and green chemistry, and outlines a roadmap for exploring the development of alginate-based coatings for different industries.