Silver deposition on nanoporous and nanotubular TiO2 films through sequential anodisation and Physical Vapor Deposition

Different aspects of multi-step anodisation tests have been investigated to broaden knowledge on the structural features and properties of nanoporous and nanotubular TiO2 anodic films having slight modifications made in sequential experiments for biomedical applications. Such modifications have significantly affected the morphology of films, even though the same parameters were kept, such as anodisation time, electrolyte composition and applied potential. Variations in the internal diameters of nanotubes were observed, in addition to the fact that nanotubular films can be converted into nanoporous ones. Once formed, films were used as substrates for Ag sputtering by Physical Vapor Deposition (PVD), but a few preliminary antibacterial tests had been carried out using different amounts of Ag to determine optimal amounts of Ag to be deposited. It was found that Ag deposition only reaches the top of nanotubular films and the content of added deposed Ag should be significantly greater than that for nanoporous ones. Furthermore, there was a slight decrease in contact angle values after Ag deposition, possibly due to the formation of a layer blocking the tops of nanotubes.