Evaluation of structural and corrosion behavior of chitosan/silver coating on Ti6Al4V/TiO2 nanotubular surface

Abstract

Materials used in biomedical applications must have good bulk and surface properties. The main goal of this work is to create a multifunctional surface based on chitosan-coated Ag-loaded TiO2 nanotubes to assess their capacity in the corrosion resistance property. In the first phase, Ag-loaded TiO2 nanotubular surfaces with different weight percentages of silver were fabricated at a constant voltage of 2 V under varied time durations of 1 min, 2 min, and 3 min. In the second phase, cathodic electrophoretic deposition (EPD) was used to coat the samples with chitosan by applying 10 V for 5 min as a constant process parameter for coating all the samples. The composition and morphology features of in-house fabricated Ag-loaded TiO2 nanotubular surface with chitosan were studied by different techniques such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffractometer (XRD), and Contact angle measurement. The corrosion resistance of the coated samples was assessed by using OCP, PDP, and EIS techniques. The results evidenced that chitosan-coated Ag-loaded (2 V 2 min) TiO2 nanotubular surface (TNT-Ag2.2/Ch) showed the best performance as a coating system when compared to an uncoated surface. Also, electrochemical corrosion studies showed better corrosion resistance for this coated sample. In this context, the chitosan that has been deposited serves as a protective barrier, facilitating the penetration of the physiological solution into the underlying metal surface. Overall, the TNT-Ag2.2/Ch coated sample showed 5 times better results when compared with icorr values. Finally, the newly developed chitosan-coated Ag-loaded TiO2 nanotubular surface improve the corrosion resistance of the polished Ti6Al4V alloy.