Multifunctional Polymer Nanocomposites for Anti-Corrosion Applications in Aggressive Environments: Design Strategies, Mechanisms, and Future Perspectives.

Corrosion of metallic structures in aggressive environments such as marine, acidic industrial, and chloride-rich conditions presents a persistent challenge, leading to significant economic, safety, and environmental consequences. Conventional polymer coatings provide limited protection due to permeability, weak adhesion, and lack of multifunctionality. This review critically examines recent advances in polymer nanocomposites as high-performance anticorrosion coatings. Key strategies include the incorporation of carbon-based nanomaterials, metal/metal oxide nanoparticles, layered silicates, and functional nanocontainers to enhance barrier properties, mechanical strength, thermal stability, and active corrosion inhibition. Mechanisms of protection, such as physical obstruction, electrochemical stabilization, and self-healing, are discussed in detail. The review also highlights fabrication methods, functionalization strategies, and characterization techniques essential for evaluating coating performance. Finally, current challenges, environmental considerations, and emerging trends, including bio-based polymers, smart responsive systems, and scalable manufacturing, are explored to guide future research and industrial applications