The localized corrosion inhibition effect of synthesized GSH-PCA Schiff base on magnesium alloy in Hanks’ Solution

Advanced corrosion inhibition strategies demand a dual focus on protective efficacy and practical service requirements. Magnesium alloys hold significant potential as biomedical metallic materials, yet their uncontrolled corrosion behavior has hindered widespread application. In this study, a novel glutathione-phenolic (GSH-PCA) Schiff base corrosion inhibitor was developed via a facile one-step synthesis method. Corrosion experiments conducted in Hanks’ balanced salt solution demonstrated that GSH-PCA exhibits excellent protective performance for ZE21B magnesium alloy, particularly in significantly mitigating the tendency for localized corrosion. Density functional theory (DFT) calculations and molecular orbital analysis revealed a dual protective mechanism: the imine group (-C = N-) facilitates chemical coordination with Mg²⁺ to form complexes, while the phenolic hydroxyl group (-OH) stabilizes these complexes through strong electrostatic interactions, enabling their adsorption onto the substrate surface to form a protective layer. Preliminary biocompatibility tests confirmed the applicability of this inhibitor in the biomedical field. This study provides technical support for regulating the degradation behavior of biodegradable magnesium alloys. Protective coatings based on the GSH-PCA system hold promising potential for controlling the degradation of magnesium alloy cardiovascular implants, thereby bridging the gap between materials science and clinical needs.