Corrosion behavior of electrochemically assembled nanoporous titania for biomedical applications

Corrosion resistance of nanoporous titania was investigated in Hank’s solution using potentiodynamic polarization and electrochemical impedance spectroscopic techniques. The phase structure, surface morphology and elemental composition of the untreated, anodized heat treated and anodized heat treated titanium specimens immersed in Hank’s solution for seven days were characterized using X-ray diffraction, atomic force microscopy and scanning electron microscopy with energy dispersive X-ray spectroscopy techniques, respectively. The X-ray diffraction technique revealed that the anodized heat treated titanium exhibited anatase structure. The atomic force microscopic and scanning electron microscopic results showed that the titanium surface has transformed from a smooth to nanoporous surface depending on the anodization conditions. The energy dispersive X-ray spectroscopy results confirmed the formation of hydroxyapatite over the anodized titanium after immersion for seven days in Hank’s solution. The electrochemical results revealed that the anodized heat treated titanium after seven day immersion in Hank’s solution showed nobler shift in corrosion potential compared to untreated and anodized titanium. Hence, the results suggested that the nanoporous titania layer developed on titanium is a promising material for application as orthopaedic implants.