TiO2 nanotube/chitosan-bioglass nanohybrid coating: fabrication and corrosion evaluation

In present work, the effect of titania (TiO2) nanotubes formation incorporated with chitosan-58S bioactive glass (TNT/Chitosan-58S BG) on physiochemical properties of titanium substrate was studied. Samples were characterized by Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Corrosion behavior of the coated samples was investigated in Ringer solution through Tafel polarization and electrochemical impedance spectroscopy measurements. Results represented that TiO2 nanotubes orderly formed on titanium substrate through electrochemical anodizing process. Moreover, Chitosan-58S BG coating was formed on the TNT layer with appropriate adhesion strength, owing to the mechanical interlocking. Variation of applied voltage (25 and 30 V) and duration of anodizing process (30, 60 and 120 min) resulted in the formation of TiO2 nanotubes with various diameters in the range of 89-99 nm. Furthermore, electrochemical evaluations illustrated that the presence of titania nanotubes and Chitosan-58S BG on Ti substrate significantly ameliorated the corrosion resistance of Titanium substrate through reducing corrosion current density (3.486 vs. 2.854 mu A cm(-2)), as well as, increasing total resistance (40.417 vs. 96.875 K Omega cm(2)). In addition, our study revealed that the surface hardness of Ti substrate improved after two step surface treatments. In summary, appropriate mechanical and electrochemical characteristics make the TNT/Chitosan-58S BG coating, a proper choice for biomedical applications. [GRAPHICS] .