A comprehensive review: Schiff base-based corrosion inhibitors for mild steel and related metals: mechanisms, structural engineering, and industrial applications.

Numerous industrial sectors, including oil and gas, petrochemical processing, maritime engineering, power production, and construction, are affected by corrosion, a persistent and financially damaging issue. Organic corrosion inhibitors, particularly Schiff bases, have become a remarkably powerful, adaptable, and environmentally friendly family of protective compounds among the many corrosion prevention options available. Due to the presence of heteroatoms and π-conjugated systems that promote strong interaction with metallic surfaces, Schiff bases with the azomethine (-C[double bond, length as m-dash]N-) functional group have significant adsorption abilities. The corrosion inhibition performance of Schiff bases is thoroughly investigated in this study, with particular attention to their synthesis, methods of adsorption (physisorption and chemisorption), structure-activity relationships, and the effect of molecular electronic characteristics on inhibition efficiency. A critical discussion is held concerning the importance of electrochemical techniques, Density Functional Theory (DFT), and Molecular Dynamics (MD) simulations in understanding inhibitory mechanisms. The paper also covers recent developments in hybrid nanostructured systems that demonstrate enhanced protective performance through synergistic effects, metal-Schiff base complexes, and polymeric Schiff bases. In light of current environmental legislation, growing attention paid to low-toxicity inhibitors, sustainable raw materials, and green synthesis methods is also discussed. Finally, the industrial applications of Schiff base inhibitors in aqueous systems, oilfield activities, and acidic pickling are reviewed. The potential of Schiff bases as high-performance, ecologically friendly corrosion inhibitors for modern industrial applications has been extensively addressed in this paper.