Photoluminescence properties and photocatalytic activities of zirconia nanotube arrays fabricated by anodization

Preparation and photocatalytic performance of ZrO2 nanotubes fabricated with anodization process

Mesoporous titanium zirconium (TiZr) oxide nanospheres with variable Ti to Zr ratios were synthesized using sol–gel chemistry followed by solvothermal treatment. These oxide nanospheres exhibited similar diameters (∼360 nm), high surface areas (from 237 ± 2 to 419 ± 4 m2 g–1), and uniform pore diameters (∼3.7 nm). Three drugs, ibuprofen, dexamethasone, and erythromycin, were loaded into the TiZr oxide nanospheres. The TiZr oxide nanospheres exhibited a high loading capacity, up to 719 mg g–1, and sustained release profiles in phosphate buffered saline (PBS) at pH 7.4. The mesoporous TiZr oxide nanospheres also exhibited hydrolytic stability, as evidenced by the retention of the integrity of the mesostructures after drug release in PBS for 21 days.

Mesoporous Titanium Zirconium Oxide Nanospheres with Potential for Drug Delivery Applications

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.

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

Enhanced bioactivity of self-organized ZrO2 nanotube layer by annealing and UV irradiation

Zirconia nanotube arrays with a diameter of 300-350 nm and a length of 100 pm were prepared by anodization of zirconium in an organic electrolyte containing NH 4 F. The zirconia layers were annealed at 200―800°C in air. The morphologies of the specimens were observed using scanning electron microscopy. The phase structure was identified by X-ray diffraction and Fourier transform infrared spectroscopy. The bioactivity of zirconia nanotubes at different annealing temperatures was assessed by simulated body fluids immersion experiments. Results show that the nanotube arrays were stable when annealed at 600°C. The tubal layers containing zirconia with a low crystallinity and amorphous structure are more bioactive compared with a well-crystallized structure.

Heye Liu

Papers

Structure and Bioactivity of Zirconia Nanotube Arrays Fabricated by Anodization