Effects of the nano-tubular anodic TiO2 buffer layer on bioactive hydroxyapatite coating.

We studied the effect of nano-tubular anodic TiO2 buffer layers on hydroxyapatite (HA) coating. The pulsed laser deposition (PLD) method was used to deposit HA on a well arranged nano-tubular anodic TiO2 (NT-ATO) buffer layer prepared by an electrochemical anodization technique. The surface morphology and chemical composition of HA coatings were characterized by using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and contact angle measurement. We found that crystalline HA coatings show well arranged porous morphologies with a favorable surface wettability. We also found that an anodic nano-tubular TiO2 buffer layer with a relatively short tube length shows a better coating morphology. The deposition process of HA on the nanotubular TiO2 buffer layer was also proposed.