Characteristic of structure and corrosion resistance of chitosan based coatings deposited on MgZnCa alloy
Creators: name: Kozina, Iryna
name: Starowicz, Maria
name: Lekka, Maria
name: Fedrizzi, Lorenzo
name: Krawiec, Halina
Publisher: name: Zenodo
Year: 2020
Subjects: Mg alloys, corrosion resistance, chitosan coatings, microstructure

description: Characteristic of structure and corrosion resistance of chitosan based coatings deposited on MgZnCa alloy<br> Iryna KOZINA1, Maria STAROWICZ1, Maria LEKKA2, Lorenzo FEDRIZZI2, Halina KRAWIEC1<br> 1 AGH University of Science and Technology, Poland<br> 2 University of Udine, Italy In recent years magnesium and its alloys, became one of the most promising biodegradable materials used as bone implants. It was investigated that<br> pure magnesium has Young modulus and density close to that of humans bones. There were performed in vitro and in vivo studies, according to those<br> studies it was proved biodegradability of magnesium and its alloys. On the same time, it was investigated that those type of materials are non-toxic<br> and no allergic. Nevertheless, it is still challenging to create magnesium based bone implants, because of its high corrosion rate of magnesium alloys<br> in the solutions containing Cl- ions.<br> In this work, was studied corrosion behaviour of magnesium alloy (Mg19Zn1Ca) protected by natural biopolymer chitosan based coatings. The<br> coatings were applied by using of spin coater. The following types of coatings were deposited on Mg19Zn1Ca substrate: chitosan, chitosan with<br> addition TiO2 nanoparticles and chitosan with addition of NaF. Chitosan was chosen as natural biopolymer, which is biodegradable and safe for<br> humans health also it is known that chitosan have antibacterial properties, and that is one of the most attractive properties of this polymer. The<br> morphology, the structure and the chemical composition of chitosan coatings have been studied by means of FE-SEM/EDS, FT-IR, XPS and optical<br> profilometry. It has been revealed that the roughness Ra of the chitosan/TiO2 and chitosan/NaF coatings was 1.3 μm, 2.7 μm, respectively. The<br> corrosion tests were performed in the Hank’s solution at constant temperature (37°C) and pH (7.2). In order to determine the corrosion behaviour of<br> tested samples, linear sweep voltamperometry (LSV) and electrochemical impedance spectroscopy (EIS) were performed. The chemical composition<br> of chitosan coatings before and after corrosion tests have been studied by means of SEM and XPS measurements. These results obtained from the<br> corrosion tests have shown that the chitosan coatings were dissolved in the Hank's solution after 7 days of immersion in it. During the immersion of<br> Mg alloy in the Hank's solution, the chitosan coatings underwent dissolution and the corrosion products were deposited on its surface. The<br> electrochemical measurements have revealed that the magnesium alloy covered by chitosan/NaF coating had a good corrosion resistance in the<br> Hank's solution.<br> Acknowledgements<br> This work has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie<br> grant agreement No 764977 – mCBEEs.