Fabrication and Characterization of Nanoporous Niobia, and Nanotubular Tantala, Titania and Zirconia via Anodization

Abstract

Valve metals such as titanium (Ti), zirconium (Zr), niobium (Nb) and tantalum (Ta) that confer a stable oxide layer on their surfaces are commonly used as implant materials or alloying elements for titanium-based implants, due to their exceptional high corrosion resistance and excellent biocompatibility. The aim of this study was to investigate the bioactivity of the nanostructures of tantala (Ta2O5), niobia (Nb2O5), zirconia (ZrO2) and titania (TiO2) in accordance to their roughness and wettability. Therefore, four kinds of metal oxide nanoporous and nanotubular Ta2O5, Nb2O5, ZrO2 and TiO2 were fabricated via anodization. The nanosize distribution, morphology and the physical and chemical properties of the nanolayers and their surface energies and bioactivities were investigated using SEM-EDS, X-ray diffraction (XRD) analysis and 3D profilometer. It was found that the nanoporous Ta2O5 exhibited an irregular porous structure, high roughness and high surface energy as compared to bare tantalum metal; and exhibited the most superior bioactivity after annealing among the four kinds of nanoporous structures. The nanoporous Nb2O5 showed a uniform porous structure and low roughness, but no bioactivity before annealing. Overall, the nanoporous and nanotubular layers of Ta2O5, Nb2O5, ZrO2 and TiO2 demonstrated promising potential for enhanced bioactivity to improve their biomedical application alone or to improve the usage in other biocompatible metal implants.

Improvement on electrochemical performances of nanoporous titania as anode of lithium-ion batteries through annealing of pure titanium foils

“…6 d) after calcination in air. The similar phenomenon was observed in the study of calcination of anodized titania [54] . The D i of NA-np-TiO 2(C) ranged from 6.10 nm to 240.20 nm while the D i of AA-np-TiO 2(C) was in a narrower range of 2.55-123.50 nm.…”

Temperature-dependent surface porosity of Nb2O5 under high-flux, low-energy He+ ion irradiation

“…Particularly for bio-applications, it is important to be able to control both the surface porosity and aspect ratio of metal-oxide nanostructures [9][10][11]. Recently, several efforts have been made by research groups all around the world to develop highly porous Nb 2 O 5 surfaces using several techniques such as electrosynthesis and anodization [12][13][14], phase transformation [15], thermal oxidation [16], and sol-gel processes [17,18]. In this study, we present a novel one-step ion irradiation processing technique for generating similar nanostructured Nb 2 O 5 surfaces with relatively large surface area and surface porosity.…”

Development of stacked porous tantalum oxide layers by anodization

“…As observed in Figure 3Figure 3-a (a1 and a2), a compact anodic layer with few isolated small diameter pores was achieved. Finally, in the last stage it reaches a steady value [24], indicatinging that the oxide formation and dissolution reactions are in equilibrium [4], [37]. As the formation of pores could be enhanced by the applied electric field for anodization [19] and that an increase of the applied potential could provide a uniform porous distribution across the surface [38], the potential was raised from 40 to 60V for different NH4F concentrations.…”