Formation and characterisation of nanoporous TiO^sub 2^ layers on microroughened titanium surfaces by electrochemical anodisation

Nanoporous titanium dioxide (TiO^sub 2^) layers were successfully formed by an electrochemical anodisation method on microroughened titanium (Ti) surfaces in fluoride containing aqueous electrolyte. Microroughened Ti surfaces were produced by sandblasting with Al^sub 2^O^sub 3^ particles of 50 µm in diameter and acid-etching in a blend of HCl/H^sub 2^SO^sub 4^ solution. The surface morphology, topography and chemical composition of the specimens were analysed by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. The surface roughness and the wettability of treated Ti surfaces were measured using profilometry and a contact angle measurement system, respectively. With anodising of sandblasted-/acid etched surfaces, micrometre- and nanometre-scale textures on titanium specimens were created. Results showed that these developed nanoporous-microroughened surfaces exhibited lower contact angle values than the other treated Ti surfaces. The sandblasted/acid-etched/anodised Ti specimen had a surface morphology with distinctively formed hills and valleys and higher surface roughness than the other anodised specimens. This study indicated that nanoporous TiO^sub 2^ structures fabricated on microroughened Ti can be an effective way to modify the titanium surfaces for the future development of implant applications. [PUBLICATION ABSTRACT]