TiO2 nanotubes highly ordered and vertically aligned were grown on Ti–7.5Mo alloy.
Raman analysis showed an increasing of the average size of the anatase crystallites.
Contact between anatase crystallites induced the phase transformation anatase–rutile.
The phase transformation lead to coalescence and subsequent collapse of the nanotubes.
Nanotubes in the anatase phase becoming the surface more hydrophilic suitable for biomedical applications.