Papers by Keyword: Titania Nanotube

Abstract: Titania nanotube arrays were formed by electrochemical anodic etching of titanium from glycerol solutions with addition of 0.5% HF and analyzed by scanning probe microscopy and ellipsometric analyzes. Potentiostatic curves allow identifying several different stages of growth of nanotubes of titanium dioxide, however, this method does not establish specific parameters of the surface. We demonstrated that analysis of the spectrum ellipsometric parameters Psi and Delta can used as a criterion of quality, frequency, depth and other characteristics of the obtained arrays of titania nanotube. The use of these methods of analysis allowed to fully characterize the different stages of growth of titania nanotube from glycerol solutions and can be used for quality control the resulting structures for various applications.

Abstract: Hydrogen peroxide (H₂O₂) is a stronger oxidizing agent relative to the commonly used H₂O in anodization of Titania Nanotube (TNT). Despite having higher oxide growth rate and more superior photocatalytic property, the substitution of H₂O₂ as oxygen source is sometimes accompanied with foil corrosion. In this work, it is shown that foil corrosion is originated from temperature elevation during anodization process. Conversely, foil corrosion can be prevented by monitoring the anodization temperature. Essentially, the corrosion of foil is not directly influenced by the type of oxidation source used. Foil corrosion occurs due to temperature elevation when using H₂O₂ as oxidation source.

Abstract: A novel and facile process called “alternative loop immersion method” formed bioactive and biocompatible Zn-doped calcium silicate coating over the drug-loaded titania nanotube arrays to improve the properties of drug release. The samples were characterized by scanning electronic microscope (SEM), x-ray diffraction (XRD) and fourier transform infrared (FT-IR). The results show that TNTs modified by Zn-doped calcium silicate coating possess improved drug release characteristics with reduced burst release (from 83% to 66%) and prolonged drug release (from 11 days to over 15 days). This approach provides an alternative to tailor the surface of TNTs and offer considerable propects for diverse biomedical applications.

Abstract: In this study, the vertically aligned titania nanotube arrays (TNTs) was fabricated on the surface of titanium substrate in fluoride-containing electrolytes via self-ordering electrochemical anodization. The prepared TNTs loaded with ibuprofen (IBU) by solvothermal to achieve a local drug delivery system and its release properties were investigated. The samples were characterized by field emission scanning electronic microscope (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR). The results indicated that the IBU drug molecules were successfully loaded on the surface of TNTs and the drug release shows a sustained release process. It suggested that TNTs as drug carrier had the properties of sustained release which have a good application prospect in biomedical field.

Abstract: Titanium dioxide (TiO₂) nanotube arrays were prepared at room temperature by electrochemical anodization of a pure titanium foil in electrolyte solutions containing ethylene glycol as a solvent and de-ionized water and ammonium fluoride as additives. Since the morphology and size of TiO₂ nanotubes play critical roles in determining their performance, the control of geometrical parameters of the nanotube arrays including length and inner diameter are of great importance. The present research demonstrates the significant effects of fluoride concentration and water content in anodizing electrolyte on formation of nanotubes and their dimensions. Scanning electron microscope investigation shows that nanotube arrays are no longer formed in very low or very high concentration of ammonium fluoride. Also, increase in fluoride concentration causes increase in lengths and inner diameters of the nanotubes. Moreover, it is evident that the maximum nanotube growth rate was achieved in medium amount of water. In addition, it is found that the nanotube inner diameter increases by adding more water to the solution.

Abstract: TiO₂ nanotube was synthesized successfully with different parameters via hydrothermal process, using nanopowder TiO₂ and concentrated NaOH solution as raw materials. If the hydrothermal temperature, hydrothermal time or washing conditions were changed, the structure of the nanotube was different. The phase compositions and morpholog ies of the TiO₂ nanotube was characterized by XRD and SEM. These results suggested that the length of the nanotube increased from 180 nm to 270 nm, and the diameter almost kept a fixed level about 15~20 nm within a range of 110°C~150°C. The length of the nanotube increased from 230 nm to 330 nm and diameter was nearly unchanged as the result of time increasing from 24 h to 48 h. Washing conditions were very important to influence the nanotube. When the deposit was washed directly with distilled water, short and thick nanorod were formated, and microrod generated with concentrated hydrochloric acid, and microrod structure with smooth surface was produced with absolute ethyl alcohol, and the nanotube was fabricated only after washing by dilute acid.

Abstract: To improve the photocatalytic properties of titania photocatalyst by incorporated Eu element during electrochemical oxidation, Eu-doped titanium oxide nanotube was synthesized by anodic process in an ethylene glycol electrolyte with Eu (NO₃)₃ as an additive. The crystalline structure and surface characteristics of Eu-doped titania nanotube were investigated. The XPS results indicate the migration of the europium element into the titania nanotube layer from mixture electrolyte during electrochemical oxidation. The Eu-doped titania nanotubes show much higher activity of dye degradation.

Abstract: In order to improve the visible light response in titania photocatalysts, CuO/TiO₂ heterojunction nanostructures (CuO-TNT) were proposed and fabricated via the electrochemical process. TiO₂ nanotubes array (TNT) was first fabricated by secondary anodization, after that the CuO was doped by the electrodeposition. The thin film was characterized by X-ray diffraction (XRD), diffuse reflection spectra (DRS) and field emission scanning electron microscopy (FESEM). Besides, its photoelectrochemical properties were measured in 0.1 M Na2SO₃ solution. By comparing the results under different conditions of deposition, it was found that the deposition current density was a crucial parameter for controlling the morphology and the photoelectrochemical properties of the samples.

Abstract: Titania nanotube (NT) arrays with a length of 550nm were fabricated on the flat titanium substrate by anodization. The microstructure was identified by scanning electron microscope. The composition has been investigated with X-ray photoelectron microscopy. It also showed that, as compared with the flat surface, the density of Ti-OH groups on the NT surface has been increased. However, according to the contact angle goniometer, the hydrophilicity of the NT surface becomes worse than that of the flat surface. In addition, surface roughness was investigated by non-contact atomic force microscope. It demonstrated that the nano-roughness of NT arrays has been increased. More important is the relationship between contact angle and roughness factor have been analyzed based on the modified Young’s equation. These results indicate that the anodized NT structures may have provided an optimal surface roughness for promoting the bioactivity.

Abstract: Titania nanotube arrays were synthesized via anodic oxidization of titanium foil in dimethyl sulfoxide (DMSO) solution containing 2 wt% HF and 3 wt% H2O at 40 V. The microstructure of the arrays was characterized with scanning electron microscopy (SEM). The results show that morphology of titania nanotube arrays is evidently influenced by the anodization time, and with the extension of oxidation time, the better morphology could be obtained. The possible formation mechanism of titania nanotube arrays has been discussed.