Polycaprolactone/ZnO coating on WE43 magnesium alloy combined with a MgO/MgCO3 transition layer for promoting anticorrosion and interfacial adhesion

Abstract

Polycaprolactone (PCL) based polymers are usually considered as potential coating materials for improve corrosion resistance of biodegradable magnesium alloy due to excellent mechanical property and biocompatibility. However, as for the quality and stability of the polymer-based coatings, the interfacial adhesion of polymer coating to magnesium substrate and the antibacterial ability should not be ignored. Herein, to improve the interfacial adhesion of PCL based coating, a MgO/MgCO3 transition layer was prepared on the biodegradable WE43 magnesium alloy by a facile chemical conversion process in a deep eutectic solvent-based ionic liquid. Moreover, ZnO nanoparticles were loaded in the PCL to form a PCL/ZnO coating on the transition layer to further enhance corrosion resistance, biocompatibility, and antibacterial activity of the magnesium alloy substrate. Electrochemical corrosion test and in vitro biocompatibility tests, including cytotoxicity and antibacterial activity, were performed in a simulated body environment, which showed that the substrate covered by the double-layered coating possesses good corrosion resistance, biocompatibility and antibacterial ability.