A novel anti-corrosion and antibacterial integrated MAO/PCNZ composite coating on AZ31B Mg alloy

Magnesium and its alloys possess elastic modulus close to natural bone and degradable effects, making them widely applied in bone implantation. However, their rapid corrosion in a simulated body fluid restricts further application. This work firstly employs micro arc oxidation (MAO) technique to in situ grow a corrosion-resistant ceramic layer on the surface of AZ31B Mg alloy. Subsequently, nano ZnO particles are modified using a silane coupling agent and then incorporated into a poly(ε-caprolactone) coating with chitosan through a simple blending and micellar method to obtain the PCNZ composite coating. The chemical composition and micro structure are characterized by FTIR, XRD, SEM and AFM. Electrochemical tests and antibacterial experiments indicate that PCNZ composite coating exhibits excellent long-term corrosion resistance and certain antibacterial ability, demonstrating potential application in the field of bone implantation.