阳极氧化纳米膜上酶固定技术的验证与应用

对阳极氧化纳米膜烷硅化和活化的表面处理后,通过与赖氨酸进行取代反应达到固定酶的目的。以蔗糖和葡萄糖为反应物,在被固定的转化酵素-葡萄糖氧化酶-辣根过氧化物酶的催化作用下,利用实时检测510 nm波长下醌亚胺的光吸收,验证了上述酶固定法在生物反应器应用中的可行性。

不同孔径的纳米多孔氧化铝膜对细胞迁移的影响

为了研究不同孔径的纳米多孔阳极氧化铝膜对细胞迁移的影响,采用扫描电镜和X射线能谱仪分别检测不同孔径纳米氧化铝膜微观结构与元素组成;将Hela细胞常规培养于激光共聚焦皿内,分为对照组、40~70 nm孔径组和200~300 nm孔径组三组,进行划痕实验;将皿放入活细胞工作站随机选取多个观测点,连续观测24 h;从迁移面积、边缘迁移距离和单细胞迁移速度等方面进行细胞迁移分析;用扫描电镜对细胞在两种膜上生长24 h后的情况进行观测。结果显示,40~70 nm孔径组与对照组相比可加快细胞迁移(P<0.05),200~300 nm孔径组与对照组相比可减缓细胞迁移(P<0.05)。该研究结果表明,纳米氧化铝膜的孔径不同对细胞迁移影响不同,这为临床研究中控制细胞行为材料的设计和研发提供了实验依据。

Formation Mechanistism Study of TiO2 Film Comprising Nanotubes and Nanoparticles

A novel titanium dioxide （TiO2） film comprising both nanotubes and nanopaticles was fabricated by an anodization process of the modified titanium. The local electric field at the anodized surface was simulated and its influence on the morphology of the TiO2 film was discussed. The results show that the electric field strength is enhanced by the covering. The growth rate of TiO2 increases with the assist of the local electric field. However, TiO2 dissolution is hindered since the local electric field prevents [TiF6]6- from diffusing. It means that the balance condition for the formation of nanotubes is broken, and TiO2 nanoparticles are formed. Moreover, the crystal structure of the TiO2 film was confirmed using X-ray diffraction and Raman analysis. The anatase is a main phase for the proposed film.

Microstructure and abrasive wear behaviour of anodizing composite films containing Si C nanoparticles on Ti6Al4V alloy

Anodized composite films containing Si C nanoparticles were synthesized on Ti6Al4 V alloy by anodic oxidation procedure in C4O6H4Na2 electrolyte. Scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and X-ray photoelectron spectroscopy(XPS) were employed to characterize the morphology and composition of the films fabricated in the electrolytes with and without addition of Si C nanoparticles. Results show that Si C particles can be successfully incorporated into the oxide film during the anodizing process and preferentially concentrate within internal cavities and micro-cracks. The ball-on-disk sliding tests indicate that Si C-containing oxide films register much lower wear rate than the oxide films without Si C under dry sliding condition. Si C particles are likely to melt and then are oxidized by frictional heat during sliding tests. Potentiodynamic polarization behavior reveals that the anodized alloy with Si C nanoparticles results in a reduction in passive current density to about 1.54×10-8 A/cm2, which is more than two times lower than that of the Ti O2 film(3.73×10-8 A/cm2). The synthesized composite film has good anti-wear and anti-corrosion properties and the growth mechanism of nanocomposite film is also discussed.

Self-Organizing Evolution of Anodized Oxide Films on Ti-25Nb-3Mo-2Sn-3Zr Alloy and Hydrophilicity

In the present work,hierarchical nanostructured titanium dioxide(TiO2) films were fabricated on Ti-25Nb-3Mo-2Sn-3Zr(TLM) alloy for biomedical applications via one-step anodization process in ethylene glycolbased electrolyte containing 0.5wt% NH4F.The nanostructured TiO2 films exhibited three distinct types depending on the anodization time:top irregular nanopores(INP)/beneath regular nanopores(RNP),top INP/middle regular nanotubes(RNT)/bottom RNP and top RNT with underlying RNP.The evolution of the nanostructured TiO2 films with anodization time demonstrated that self-organizing nanopores formed at the very beginning and individual nanotubes originated from underlying nanopore dissolution.Furthermore,a modified two-stage self-organizing mechanism was introduced to illustrate the growth of the nanostructured TiO2 films.Compared with TLM titanium alloy matrix,the TiO2 films with special nano-structure hold better hydrophilicity and higher specific surface area,which lays the foundation for their biomedical applications.

Fabrication of silver nanoparticles decorated anodic aluminum oxide as the SERS substrate for the detection of pesticide thiram

An efficient surface-enhanced Raman scattering(SERS) substrate is developed based on silver nanoparticles decorated anodic aluminum oxide(Ag/AAO).The AAO templates were fabricated using a two-step anodization approach,and silver nanoparticles(Ag NPs) were obtained by thermal decomposition of Ag nitrate in AAO.The structure of Ag/AAO hybrid substrate is characterized by scanning electron microscopy(SEM).The results show that the as-prepared SERS substrates consist of high-density Ag NPs with sizes of tens of nanometers.The Ag NPs are adsorbed on the surface of AAO template in the form of network structure which is called "hot spot".The SERS enhancement ability of the nanostructure is verified using thiram as probing molecules.The limit of detection is as low as 1×10-9 mol/L.The results indicate that the as-prepared substrate possesses excellent SERS sensitivity,high stability and uniformity enhancement.