Synthesis of oxide nanotubes on Ti13Nb13Zr alloy by the electrochemical method

Abstract

Surface modification of titanium alloys expands the range of their applicability in medicine, particularly in the form of various implants. Present work reports the results of the electrochemical formation of self-ordered oxide nanotubes on Ti13Nb13Zr alloy. Due to its relatively low Young modulus (77-79 GPa) this alloy can be attractive material for orthopedic application. The experiments were conducted in the (NH 4) 2 SO 4 + NH 4 F electrolyte at room temperature. Anodization of the alloy samples was carried out for 2 h under variable external potential U (in the range from 10 to 45 V) and the current versus time transients were recorded. Obtained surface morphology was investigated by the scanning electron microscopy and the X-ray techniques. The morphological parameters of the obtained nanotubes such as the inner (d in) and outer (d out) diameters were determined. The tubes diameter dependence on the voltage of anodization process was derived. The dependence d[nm] = f(U) [V] was established at constant temperature 25 °C. It provides the basis for controlled oxide nanotubes layer growth. It was also demonstrated that these nanotubes exhibit photocatalytic activity.

Production and Characterization of the Third-Generation Oxide Nanotubes on Ti-13Zr-13Nb Alloy

“…The shape of the obtained curves is not similar to the current transients observed in the literature for forming ordered titania nanotubes in an ethylene glycol electrolyte without and with the addition of 0.13–1 wt% water in the presence of fluoride ions [ 48 ]. In Figure 2 , the behavior of the anodic current density as a function of time shows similarity to the current transient observed for the Ti-13Zr-13Nb electrode during anodizing in 0.5 wt% HF [ 36 ] and in 1 M (NH 4 ) 2 SO 4 + 0.5 wt% NH 4 F [ 37 ] electrolytes. The typical initial decay and the increase in the anodic current density before reaching the quasi-steady-state value are observed in 1 M C 2 H 6 O 2 electrolyte containing 4 wt% NH 4 F. The inset of Figure 2 b for the first 80 s of anodizing shows that the quasi-steady-state conditions are achieved more quickly with increasing anodizing voltage.…”

“…The linear equations describing the change of the SWNTs diameters as a function of the anodizing voltage are presented in Figure 5 . Comparing these equations with the equations determined for second-generation SWNTs on the Ti-13Zr-13Nb alloy [ 37 ] and second-generation SWNTs on the Ti-6Al-7Nb alloy [ 50 ] obtained by anodizing for 120 min in 1 M (NH 4 ) 2 SO 4 + 0.5 wt% NH 4 F shows that D outer growth is the fastest for third-generation SWNTs on the Ti-13Zr-13Nb alloy in 1 M C 2 H 6 O 2 + 4 wt% NH 4 F electrolyte, whereas D inner growth is the slowest. The obtained results indicate that the thickest walls characterize third-generation SWNTs on the Ti-13Zr-13Nb alloy.…”

“…Currently, intensive research is carried out to develop innovative surface modification methods of the biomedical Ti-13Zr-13Nb alloy to increase its bioactivity, biocompatibility, and long-term stability [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. Electrochemical modification can carry out additional functionalization of the Ti-13Zr-13Nb alloy surface, increasing its osteoinductive properties for applications in regenerative medicine and intelligent drug delivery systems [ 29 ].…”

“…A self-passive oxide layer on the Ti-13Zr-13Nb alloy surface and its electrochemical properties play an essential role in the long-term implantation [ 15 ]. The biocompatible properties of the Ti-13Nb-13Zr alloy can be additionally improved by creating a porous oxide layer on its surface using electrochemical methods [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. Obtaining a porous surface of the Ti-13Zr-13Nb alloy enables the development of innovative long-term implants with increased osteoinductive properties.…”

“…An attempt was made to oxidize the solid and porous Ti-13Zr-13Nb alloy in H 3 PO 4 with the addition of HF to form high corrosion-resistant nanotubular layers [ 34 , 35 ]. The ONTs with controlled morphology, length, and diameter on the Ti-13Nb-13Zr alloy were also obtained by anodizing room temperature in hydrofluoric acid solution [ 36 ], in (NH 4 ) 2 SO 4 + NH 4 F solution [ 37 , 38 , 39 , 40 ], and in ethylene glycol solution with the addition of NH 4 F [ 41 ].…”