Self‐organized nanotubular oxide layers on Ti‐6Al‐7Nb and Ti‐6Al‐4V formed by anodization in NH<sub>4</sub>F solutions

Macák, Jan M.; Tsuchiya, Hiroaki; Taveira, Luciano; Ghicov, Andrei; Schmuki, Patrik

doi:10.1002/jbm.a.30501

Cited by 263 publications

(186 citation statements)

References 25 publications

Supporting

Mentioning

173

Contrasting

Unclassified

Order By: Relevance

“…They were mechanically polished on cloth to 1 μm and ultrasonically cleaned using deionized water and acetone. The samples having area of 1.13 cm 2 were anodized in electrolyte containing 1 M (NH 4 ) 2 SO 4 (POCH) and 0.5 wt% NH 4 F (POCH) [18]. During all anodization processes, the electrolyte was stirred using magnetic stirrer.…”

Section: Methodsmentioning

confidence: 99%

Electrochemical synthesis of oxide nanotubes on Ti6Al7Nb alloy and their interaction with the simulated body fluid

Stępień

Handzlik

Fitzner

2016

J Solid State Electrochem

View full text Add to dashboard Cite

The aim of the present work was to investigate electrochemical behavior of the Ti6Al7Nb alloy in the simulated body fluid (SBF) containing Ca 2+ , HCO 3 − , and HPO 4 2 − ions. At first, optimal conditions necessary for oxide nanotube formation were determined. The experiments were conducted in the 1 M (NH 4 ) 2 SO 4 with 0.5 wt% NH 4 F electrolyte at room temperature. Anodization of the alloy samples was carried out under variable external voltage U in the range from 10 to 40 V at room temperature. Obtained surface morphology was examined by SEM and X-ray techniques. Nanotube diameter was calculated and correlated with the imposed voltage. Having control over the size of nanotubes, samples with the obtained nanostructures of a chosen diameter were immersed into SBF solution with pH = 7.4 for a fixed period of time. Then, they were removed from the fluid and subjected to the electrochemical investigation. Corrosion current and corrosion potential were determined, and it was found that the best anticorrosion properties were obtained for heat-treated nanotube layer: i corr = 39 nA/cm 2 and E corr = −0.236 V vs Ag/AgCl. Finally, the interaction between the oxide surface and the solution was studied using polarization and electrochemical impedance spectroscopy (EIS) techniques.

show abstract

Section: Methodsmentioning

confidence: 99%

Electrochemical synthesis of oxide nanotubes on Ti6Al7Nb alloy and their interaction with the simulated body fluid

Stępień

Handzlik

Fitzner

2016

J Solid State Electrochem

View full text Add to dashboard Cite

show abstract

“…TNTs have been used for different applications such as DNA biosensor [10], detection of bacteria [11] and toxic compounds [12]. TNTs have also been explored for immobilizing proteins and enzymes in biomaterial and biosensor applications [13,14]. Many of the application are related to the photocatalytic activity of TNTs, which is usually evaluated by variations in photocurrent and absorbance under illumination.…”

mentioning

confidence: 99%

Electron Work Function–An Effective Parameter for In-situ Reflection of Electron Activities in Various Processes

Li¹

2013

J Biosens Bioelectron

View full text Add to dashboard Cite

Electron work function (EWF) is the minimum energy required to move electrons at the Fermi level from inside a conducting material to its surface with zero kinetic energy [1,2]. This fundamental parameter largely reflects electron activities and is directly related to chemical, physical, and mechanical properties of materials [2][3][4][5][6][7][8]. Recent studies have shown that EWF can be used as a sensitive parameter to characterize many surface properties of biomaterials. As an example [9], the affinity of medical implant materials for bacteria can be characterized by EWF. Figure 1A illustrates the adhesive forces of nanocrystalline stainless steel samples with different gran sizes. As shown, as the grain size decreases, the adhesion decreases due to the fact that the passive film becomes more protective, blocking the interaction between the steel and surrounding media. Such a trend is consistent with the variations in electron work function, as shown in Figure 1B. A higher surface EWF corresponds to a higher degree of reluctance for interacting with the environment. The decrease in the number of bacteria bound to the surfaces with an increase in EWF provides direct evidence.Another example is the use of EWF in analyzing the photocatalyical activity of TiO2 nanotubes (TNTs). TNTs have been used for different applications such as DNA biosensor [10], detection of bacteria [11] and toxic compounds [12]. TNTs have also been explored for immobilizing proteins and enzymes in biomaterial and biosensor applications [13,14]. Many of the application are related to the photocatalytic activity of TNTs, which is usually evaluated by variations in photocurrent and absorbance under illumination. However, the photocurrent response or absorbance does not provide sufficient information for full understanding of the photocatalytic behaviour of TNAs.Recent studies have demonstrated that the electron work function is a very sensitive parameter for in-situ analysis of photocatalytic activity of TNTs [15]. Figure 2 illustrates variations in the work function of TiO 2 nanotubes with different tube lengths (corresponding to the anodization duration; the larger the anodization duration, the longer the nanotubes). Figures 2A, C, E and G illustrate variations in EWF of the TNAs illuminated successively by lights having wavelengths of 670 nm, 650 nm, 550 nm, 450 nm, 420 nm, 400 nm and 390 nm. As shown, EWF of the TNAs was relatively stable when they were illuminated by lights of 670 nm and 620 nm, indicating that the photonic energies of the lights are not sufficient to excite electrons in the TNAs. While when the wavelength of incident light is in the absorption range of TNAs lower than 550 nm, electrons can be excited accompanied with an apparent decrease in EWF. The observed decrease in EWF with a decrease in the wavelength of incident light is an indication of photoninduced electron-hole separation, which requires photons with their energy above a certain level.The TNAs were also illuminated successively by the lights with different ...

show abstract

“…3 Furthermore, during the last years, it was shown that also other valve metals, such as Zr [15][16][17] and Nb [18,19], and several Ti binary [20][21][22], ternary [23,24] and quaternary alloys [25,26] can be anodized to nanotubular or nanoporous structures in fluoride containing electrolytes. The nanotubes grown on these alloys are similar to pure TiO 2 nanotubes.…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

Self-organized double-wall oxide nanotube layers on glass-forming Ti-Zr-Si(-Nb) alloys

Sopha

Pohl

Damm

et al. 2017

Materials Science and Engineering: C

Self Cite

View full text Add to dashboard Cite

In this work, we report for the first time on the use of melt spun glass-forming alloysTi 75 Zr 10 Si 15 (TZS) and Ti 60 Zr 10 Si 15 Nb 15 (TZSN) -as substrates for the growth of anodic oxide nanotube layers. Upon their anodization in ethylene glycol based electrolytes, highly ordered nanotube layers were achieved. In comparison to TiO 2 nanotube layers grown on Ti foils, under the same conditions for reference, smaller diameter nanotubes (~116 nm for TZS and ~90 nm for TZSN) and shorter nanotubes (~11.5 µm and ~6.5 µm for TZS and TZSN, respectively) were obtained for both amorphous alloys. Furthermore, TEM and STEM studies, coupled with EDX analysis, revealed a double-wall structure of the as-grown amorphous oxide nanotubes with Ti species being enriched in the inner wall, and Si species in the outer wall, whereby Zr and Nb species were homogeneously distributed.

show abstract

Self‐organized nanotubular oxide layers on Ti‐6Al‐7Nb and Ti‐6Al‐4V formed by anodization in NH₄F solutions

Cited by 263 publications

References 25 publications

Electrochemical synthesis of oxide nanotubes on Ti6Al7Nb alloy and their interaction with the simulated body fluid

Electrochemical synthesis of oxide nanotubes on Ti6Al7Nb alloy and their interaction with the simulated body fluid

Electron Work Function–An Effective Parameter for In-situ Reflection of Electron Activities in Various Processes

Self-organized double-wall oxide nanotube layers on glass-forming Ti-Zr-Si(-Nb) alloys

Contact Info

Product

Resources

About

Self‐organized nanotubular oxide layers on Ti‐6Al‐7Nb and Ti‐6Al‐4V formed by anodization in NH4F solutions

Cited by 263 publications

References 25 publications

Electrochemical synthesis of oxide nanotubes on Ti6Al7Nb alloy and their interaction with the simulated body fluid

Electrochemical synthesis of oxide nanotubes on Ti6Al7Nb alloy and their interaction with the simulated body fluid

Electron Work Function–An Effective Parameter for In-situ Reflection of Electron Activities in Various Processes

Self-organized double-wall oxide nanotube layers on glass-forming Ti-Zr-Si(-Nb) alloys

Contact Info

Product

Resources

About

Self‐organized nanotubular oxide layers on Ti‐6Al‐7Nb and Ti‐6Al‐4V formed by anodization in NH₄F solutions