Surface Modification of Biodegradable Magnesium Alloys

The native and anodically formed oxide films on the Mg alloy (AZ91D) surface were modified with the self assembling monolayers (SAMs) of long chain carboxylic acids to protect the alloy degradation in a physiological solution. X ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) were combined to evaluate structural properties of the surface layers. To use the SAM of long chain organic acids has a potential for designing specific interface architectures in degradable implants technology. The protecting properties of native and anodically formed oxide layers alone and modified with SAM of hexadecanoic (palmitic, PA) acid and octadecanoic (stearic, SA) acid were studied in Hank’s solution using electrochemical impedance spectroscopy (EIS) and voltammetry methods. The results obtained have shown a beneficial effect of anodization and especially of the oxide layer modification by forming SAMs of long chain carboxylic acids on the corrosion properties of AZ91D alloy.