Sol–gel derived Ta-containing TiO2 films on surface roughened NiTi alloy
来源期刊：Rare Metals2014年第1期
论文作者：Bing-Hui Dong Feng Wu Zafer Alajmi Chen Zhang Tao Fu Yuan Ge
文章页码：21 - 27
摘 要：The surface of NiTi alloy was roughened by NaOH–HCl treatment, and the Ta-containing TiO2 films were coated on the pretreated NiTi alloy by the sol–gel method. Thermal analyses indicate that the evaporation temperature of the organics decreases with the addition of tantalum ethoxide in the TiO2 sol, but the crystallization temperature of anatase increases. The NaOH–HCl pretreatment improves the film integrity, but cracks still form in the films at high Ta contents（C20 %, molar ratio） owing to the increasing film thickness. X-ray diffraction（XRD） confirms that the addition of Ta suppresses the crystallization of anatase. X-ray photoelectron spectroscopy（XPS） reveals that Ta exists as Ta2 O5 in the film. With the increase of Ta content, the hydrophilic conversion of the films under UV illumination is impeded, but their corrosion resistance in 0.9 % NaCl solution increases, tested by the potentiodynamic polarization. The coating samples have acceptable hemolysis ratios for biomaterials（\5）. The introduction of Ta improves the anti-aggregating function of the TiO2 film in the platelet adhesion test.
Bing-Hui Dong1，Feng Wu2，Zafer Alajmi1，Chen Zhang1，Tao Fu1，Yuan Ge3
1. Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology,Xi’an Jiaotong University2. College of Medicine, Xi’an Jiaotong University3. State Key Laboratory of Porous Metal Materials, Northwest Institute for Nonferrous Metal Research
摘 要：The surface of NiTi alloy was roughened by NaOH–HCl treatment, and the Ta-containing TiO2 films were coated on the pretreated NiTi alloy by the sol–gel method. Thermal analyses indicate that the evaporation temperature of the organics decreases with the addition of tantalum ethoxide in the TiO2 sol, but the crystallization temperature of anatase increases. The NaOH–HCl pretreatment improves the film integrity, but cracks still form in the films at high Ta contents（C20 %, molar ratio） owing to the increasing film thickness. X-ray diffraction（XRD） confirms that the addition of Ta suppresses the crystallization of anatase. X-ray photoelectron spectroscopy（XPS） reveals that Ta exists as Ta2 O5 in the film. With the increase of Ta content, the hydrophilic conversion of the films under UV illumination is impeded, but their corrosion resistance in 0.9 % NaCl solution increases, tested by the potentiodynamic polarization. The coating samples have acceptable hemolysis ratios for biomaterials（\5）. The introduction of Ta improves the anti-aggregating function of the TiO2 film in the platelet adhesion test.
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