Investigation of the Oxidation Mechanism of Dopamine Functionalization in an AZ31 Magnesium Alloy for Biomedical Applications
Department of Nano-Technology and Advanced Materials, Institute of Materials and Energy (MERC), 31787-316 Alborz, Iran
Institute of Materials Science, Joining and Forming, Graz University of Technology, Kopernikusgasse 24/l, A-8010 Graz, Austria
Authors to whom correspondence should be addressed.
Coatings 2019, 9(9), 584; https://doi.org/10.3390/coatings9090584
Received: 9 July 2019 / Revised: 10 August 2019 / Accepted: 12 September 2019 / Published: 16 September 2019
(This article belongs to the Special Issue Surface Engineering of Light Alloys)
Implant design and functionalization are under significant investigation for their ability to enhance bone-implant grafting and, thus, to provide mechanical stability for the device during the healing process. In this area, biomimetic functionalizing polymers like dopamine have been proven to be able to improve the biocompatibility of the material. In this work, the dip coating of dopamine on the surface of the magnesium alloy AZ31 is investigated to determine the effects of oxygen on the functionalization of the material. Two different conditions are applied during the dip coating process: (1) The absence of oxygen in the solution and (2) continuous oxygenation of the solution. Energy dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) are used to analyze the composition of the formed layers, and the deposition rate on the substrate is determined by molecular dynamic simulation. Electrochemical analysis and cell cultivation are performed to determine the corrosion resistance and cell’s behavior, respectively. The high oxygen concentration in the dopamine solution promotes a homogeneous and smooth coating with a drastic increase of the deposition rate. Also, the addition of oxygen into the dip coating process increases the corrosion resistance of the material.