Effects of Surface Roughness and Chemical Species on Hydrophilicity of Anodized Film on Ti-6Al-4V Formed at a Low Current Density

摘要

Anodization of Ti-6Al-4V is crucial for dental implants because it promotes the roughness, chemical species and hydrophilicity of the surface that leads to its biocompatibility. The anodized film was prepared by the galvanostatic method at a low current density in either 1 M H_3PO_4 or 1 M NaOH as the electrolyte. The as-anodized film showed a significant decrease in the water contact angle, likely to be due to an increased surface roughness (as revealed by scanning electron and atomic force microcopy) and change in the surface species (as revealed by X-ray photoelectron spectroscopy, XPS). XPS analyses confirmed that the Ti_2p spectra scarcely changed while the O1s spectra significantly changed due to Ti-OH bonding. Moreover, the O/Ti ratio of the as-anodized film was increased. The results suggest that anodization by the galvanostatic method at a low current density in 1 M H_3PO_4 or 1 M NaOH could enhance the surface roughness and chemical surface species, and that both are likely to be important factors for enhancing the hydrophilicity of the anodized films.