Corrosion behavior of polypyrrole (PPy)-coated AZ91D Mg alloy was studied in simulated body fluid (SBF) solution at body temperature. Hydrogen gas collection measurements, polarization curves, and electrochemical impedance spectroscopy (EIS) results demonstrate that the adherent PPy coatings can significantly hinder anodic dissolution of the Mg alloy substrate; moreover, evidence is found that the enhancement of the corrosion resistance is because of the release of dopant anions. Further functionalization of PPy layers with albumin (Alb) monolayers provides additional corrosion protection and, furthermore, a better controlled release profile of the dopant anions over 20 days with zero-order kinetics

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