搅拌方法对阳极氧化法制备TiO2纳米管阵列的影响

将Ti箔在电压为40 V、温度为60℃,超声搅拌或磁力搅拌下质量分数0.25%的NH4F+体积分数2.5%的蒸馏水+乙二醇电解液中进行阳极氧化,以制备TiO2纳米管阵列;所制备的样品在空气中经450℃退火3 h。用场发射扫描电镜、透射电镜对所制得的样品表面形貌和晶体结构进行表征。结果发现:磁力搅拌制得的样品表面被严重腐蚀;而超声搅拌下可制备出完整的TiO2纳米管,无腐蚀现象;阳极氧化后的TiO2纳米管为非晶态结构,经退火处理后转变为锐态矿结构。对不同搅拌方式影响TiO2纳米管阵列的形成机制进行了分析讨论。     

Formation of crystalline TiO2 by anodic oxidation of titanium

Formation of crystalline TiO2(anatase) films by anodic oxidation of titanium foils in ethylene glycol(EG) based electrolytes at room temperature has been investigated.By varying the anodizing parameters such as the amounts of water and NH4 F added,applied voltage and anodization time,anodic TiO2 films with different crystalline structures were obtained.Scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray powder diffraction(XRD) characterizations were employed to determine the morphologies and crystalline structures of as-prepared anodic TiO2 films.The results indicate that crystallization of anodic TiO2 films was generally facilitated by high fluoride concentration,high applied voltage and longer anodization time,and the formation of anodic TiO2 films with best crystallinity could only be achieved when optimized amounts of water were added.     

3D printed titanium scaffolds with ordered TiO2 nanotubular surface and mesoporous bioactive glass for bone repair

Titanium alloy scaffolds have recently gained substantial interest for the treatment of critical-size bone defect, particularly along with the maturity of the 3D printing technology that is capable of turning scaffold design ideas into real implants. As titanium alloys lack surface osteogenic activity, for improved biological performance of such scaffolds, surface modification is necessary. Various coating materials and coating methods have been explored. In this study, we developed a unique surface modification method to provide the surface of 3D printed titanium scaffolds with nano-sized structure and bioactive agent. Uniform, ordered TiO₂ nanotube arrays were formed by applying two-step anodization, and then mesoporous bioactive glass (MBG) was loaded into nanotubes. The results of in vitro immersion testing showed that bioactive ions, i.e., Si and Ca ions, could be steadily and continuously released from MBG into basal medium. The assessment of the responses of hBMSCs confirmed that the surface-modified scaffolds supported the adhesion and proliferation of hBMSCs, indicating good surface cytocompatibility. The developed method of combining surface nanostructure and bioactive agent could be used as a new strategy to improve the osteogenic activity of 3D printed titanium alloy scaffolds.     

氧化铝湿敏元件及其稳定性研究

本文论述了电容式氧化铝湿敏元件的感湿原理及多孔氧化铝的成膜机理。通过特性的测试比较,确定了较工艺条件及合理的元件结构,并应用不同的方法对好的影响元件感湿特性的因素进行了分析处理,使其稳定性得以提高。