Induced antibacterial capability of TiO2 coatings in visible light via nitrogen ion implantation

In order to enhance the antibacterial ability of titanium components,an antibacterial coating was fabricated on Ti surface by micro-arc oxidation(MAO)and further nitrogen plasma immersion ion implantation(N-PIII).The XPS spectra demonstrated that nitrogen was incorporated into TiO2 coatings by N-PIII and the nitrogen content on the surface of TiO2 coatings increased as the N-PIII time increased.Nitrogen-incorporated samples exhibited remarkably increased absorbance in the visible region and the light absorption edge of nitrogen-incorporated samples showed a redshift compared to MAO samples.Escherichia coli and Staphylococcus aureus were seeded on the samples to assess their antibacterial ability.The bacterial experiment demonstrated that nitrogen-incorporated TiO2 could effectively reduce the bacterial viability in visible light.Thus,the antibacterial TiO2 coatings fabricated by MAO and further N-PIII might have large potential in the medical and marine fields.

DEFLECTION METHOD FROM TWO SIDES OXIDATION TO STUDY EFFECT OF Y ON INTERNAL STRESS OF OXIDE SCALES

Au investigation was carried ont of the effect of Y addition upon the internal stress of Al_2O_3 scale formed during oxidation of sputtering coating on Co-30Cr-6Al alloy and the growth stress of oxidized film on Fe-23Cr-5Al alloy heating up to 900℃ in air,using a specially designed deflection method from thin strip specimen with coat- ings,ion-implanted Y on one side and oxidized onto both sides.Results indicate that Y may decrease the internal stress of oxide scale on 2×10^(17) Y^+/cm^2 implanted Co- 30Cr-6Al coating,and increase one on 2×10^(16) Y^+/cm^2 implanted Fe-23Cr-5Al alloy. This seems due to whether or not Y promotes the plastic deformation of oxide scale.In addition,at initial oxidation stage,the change of growth stress of oxide scale formed on Y-implanted Co-30Cr-6Al coating may be related to the influence of Y on oxidation process of the coating.

AN ABNORMAL BEHAVIOR OF NANO-CRYSTALLINE IN SiO_2 SUBSTRATE

Temperature dependence of the hyperfine field of Fe nanocrystalline in SiO2matrix prepared by using an ion implantation and subsequent heat treatment can not be described by a formula for the isolated Fe nanocrystalline.The large stresses or chemical bond force to which interface atoms may be subjected lead to increase effective anisotropic constant. In addition a little concentration of oxygen atoms contained in the crystalline might enhance the hyperfine field.

用氮离子注入硅中抑制SiO_2的生长

本文报道了硅片在相同的氧化条件中形成不同厚度的SiO_2层。采用注入氮离子进入硅中,将注入与未注入样品在1000℃的炉温中进行干氧、湿氧生长SiO_2,用膜厚测试仪测SiO_2层的厚度。结果表明,N_2^+离子注入硅样品的氧化层厚度明显薄于非注入样品的氧化层厚度。N_2^+离子注入硅表面在氧化时抑制SiO_2的生长,具有较明显的抗氧化的作用。这项实验说明,采用注入N_2^+离子,同一硅片在相同的氧化条件下开辟选择氧化是可能实现的。

双面氧化弯曲法研究钇对氧化膜内应力的影响

采用条状试样单面离子注入稀土钇双面氧化弯曲的氧化膜应力分析技术,研究了钇对形成Al_2O_3的合金和涂层氧化膜生长应力的影响,结果表明,在实验注入的剂量范围,钇能降低Co—30Cr—6Al溅射涂层上氧化膜应力,相反地增大了Fe一23Cr—5Al合金上氧化膜应力,认为其原因在于钇是否促进了氧化膜的塑性形变,另外,注入钇的Co—30Cr—6Al涂层初始氧化时膜内应力的变化与钇对涂层氧化机制的影响有关。

纳米SiO_(2)对霍山石斛生长的影响

为了解纳米材料对植物生长的影响,以霍山石斛为材料,将不同浓度的纳米SiO_(2)加入培养基中,研究纳米SiO_(2)对霍山石斛生长的形态特征、抗氧化酶活性、叶绿素含量的影响,以期为霍山石斛的人工栽培及野生资源保护提供一定的参考。结果表明,随着纳米SiO_(2)添加比例的增加,长势呈现逐渐减缓的趋势;抗氧化酶活性在低浓度纳米SiO_(2)处理中有所提升,在高浓度中出现下降;叶绿素含量在低浓度纳米SiO_(2)处理中下降比高浓度处理显著。由此可见,添加纳米SiO_(2)对霍山石斛的生长构成了逆境胁迫,但在生长期内没有显著影响其正常生长。

Investigation of structural and magnetic properties of Ni implanted rutile

In this paper,the structural and magnetic properties of Ni metal implanted TiO 2 single crystals are discussed.Ni nanocrystals (NCs) have been formed in TiO 2 after ion implantation.Their crystalline sizes were increased with increasing post-annealing temperature.Metallic Ni NCs inside the TiO 2 matrix are stable up to an annealing temperature of 1073 K.The Ni NCs forming inside TiO 2 are the major contribution of the measured ferromagnetism.