纯钛表面TiO2多孔膜的制备及其晶型研究

以硫酸为电解液,纯钛(TA1)为阳极,铜片为阴极,以恒压和恒流阳极氧化方式在钛表面直接获得锐钛型和金红石型TiO2多孔膜.采用X射线衍射仪对覆在钛基体上的阳极氧化膜进行了结构分析,研究了电压、硫酸浓度、阳极氧化时间和电流密度对TiO2多孔膜晶型的影响,并讨论了其形成机理.结果表明:在0.5 mol/L硫酸溶液中,恒压(≥80 V)或恒流(≥0.6 A)时出现锐钛相TiO2;恒压(≥100 V)1 min时即可出现锐钛相TiO2;恒压(≥150 V)或恒流(≥0.8 A)时出现金红石相TiO2.     

Photocatalytic activity of porous TiO2 films prepared by anodic oxidation

Anatase titanium dioxide is an active photocatalyst, however, it is difficult to be immobilized on the substrate. The crystalline TiO2 porous film was prepared directly on the surface of pure titanium by anodic oxidation. The film was then used for photocatalysis via the methyl orange degradation method. The effects of anodization voltage, pH value, TiO2 film area and degradation time on the photocatalyst were investigated respectively by UV-visible spectrum. It was indicated that the TiO2 film prepared by anodic oxidation at 140 V had the best photocatalysis capability and the degradation of methyl orange was accelerated with acid addition.     

Electrodeposition of photocatalytic TiO2 film on surface of alumina prepared by anodic oxidation

A new electrochemical method to prepare photocatalytic TiO2 thin film was developed, by which the TiO2 was electrodeposited on surface of alumina by AC electrolysis in solution consisting of K2 [TiO(C2O4 )2] and C2H2O4. The deposited TiO2 thin film was primarily characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and energy dispersive spectrum (EDS) methods. The photocatalytic properties of this film were also studied by the photocatalytic degradation of methyl orange. The results show that the TiO2 film electrodeposited by this method is mainly in amorphous and with a little crystalline component mixed anatase and rutile. The surface of the alumina prepared by anodic oxidation is porous and the TiO2 electrodeposited on it is scattered and incompact. TiO2 thin film fixed on the surface of alumina shows photocatalytic activity to the degradation of methyl orange.     

电解液对纯钛表面TiO2多孔膜形态及晶型的影响

以硫酸和氢氟酸为电解液,采用恒压阳极氧化方式,在TA1表面获得多孔TiO2膜,并研究了电解液对TA1表面TiO2多孔膜形态和晶型的影响规律.利用场发射扫描电镜和X射线衍射仪观察了多孔膜的形貌和结构,并对不同晶型多孔TiO2膜的形成机理进行了初步的探讨.结果表明:在硫酸电解液中,通过阳极氧化能够在TA1表面直接形成锐钛型和金红石型TiO2多孔膜,且孔径为100～200 nm;在氢氟酸电解液中,TA1表面获得了大面积的非晶纳米多孔TiO2结构,孔径为10～50 nm.     

阳极氧化法制备TiO2多孔膜

通过对TiO2多孔膜阳极氧化制备工艺的研究，提出了其成膜机理。实验以硫酸为电解液，以纯钛(TAl)为阳极，铜片为阴极，采用了恒压和恒流2种阳极氧化方式，在纯钛的表面获得TiO2多孔膜。用FESEM观察其孔径分布在100nm～200nm之间，并且随着阳极氧化电压和电流密度的增加，多孔膜的孔径有增大的趋势。最后，讨论了在硫酸电解液中TiO2多孔膜的形成机制。     

高孔隙率多孔钛的制备及微弧氧化改性

以商业用纯钛粉为原料,添加造孔剂碳酸氢铵,通过真空烧结的方法制备了多孔钛。再在浓度为10%稀硫酸溶液的电解液中对制备的多孔钛进行微弧氧化处理。将微弧氧化(MAO)改性后的多孔钛浸泡于模拟体液(SBF)中检测其生物活性,并采用SEM和XRD对改性前后多孔钛及矿化后的样品进行了表征。结果显示,制备的多孔钛孔隙率为70%,其孔结构主要包括两类：即尺寸为几百微米的相互贯通的大孔和分布在大孔壁上的尺寸为几微米的小孔。在电压为100 V下氧化2 min能在多孔钛壁上形成厚度为几百纳米的多孔TiO膜层,且该膜层能诱导磷灰石的形成。这表明,微弧氧化处理后的多孔钛具有优异的生物活性。     

氧化热对铝合金硬质氧化膜的影响(英文)

采用自制的实验装置和硫酸电解液研究阳极氧化热对铝合金2024硬质氧化膜的影响。与氧化热由氧化膜传递到电解液中相比,氧化热由铝基体传递到冷却液中有利于氧化膜的生长,成膜速度、膜厚、致密度和硬度显著提高,并随着冷却液过冷度的增大而增大。氧化膜生长所需的冷却液过冷度与电解液过冷度、铝基体壁厚、氧化膜厚度、气泡覆盖特性参数以及电流密度有关。可通过控制冷却液温度来控制氧化膜的微观结构和性能。     

ZrO_2／TiO_2复合光催化膜的微弧氧化法制备及表征

采用微弧氧化方法和原位生成的Zr（OH）_4胶体颗粒,在纯钛基体上制备ZrO_2／TiO_2复合光催化膜。采用SEM、EDX、XRD、UV-VisDRS等分析手段,对膜层进行分析表征。结果表明：复合膜显示出层状和多孔的结构,由锐钛矿、金红石和ZrO_2组成;相对于纯TiO_2膜,复合膜层的光吸收截止边缘产生红移;ZnO_2／TiO_2复合膜层和纯TiO_2膜层在紫外光照射下,对罗丹明B的光催化速率常数分别为0．0442和0．0186h~（-1）。     

Calcination/acid-activation treatment of an anodic oxidation TiO<Subscript>2</Subscript>/Ti film catalyst

The aim of this work was to investigate the effects of calcination/acid-activation on the composition, structure, and photocatalytic (PC) reduction property of an anodic oxidation TiO₂/Ti film catalyst. The surface morphology and phase composition were examined by scanning electron microscopy and X-ray diffraction. The catalytic property of the film catalysts was evaluated through the removal rate of potassium chromate during the PC reduction process. The results showed that the film catalysts were composed of anatase and rutile TiO₂ with a micro-porous surface structure. The calcination treatment increased the content of TiO₂ in the film, changed the relative ratio of anatase and rutile TiO₂, and decreased the size of the micro pores of the film catalysts. The removal rate of potassium chromate was related to the technique parameters of calcination/acid-activation treatment. When the anodic oxidation TiO₂/Ti film catalyst was calcined at 873 K for 30 min and then acid-activated in the concentrated H₂SO₄ for 60 min, it presented the highest catalytic property, with the removal rate of potassium chromate of 96.3% during the PC reduction process under the experimental conditions.     

Highly ordered self-organized TiO2 nanotube arrays prepared by a multi-step anodic oxidation process

Highly ordered TiO₂ nanotube arrays were prepared using a self-templating multi-step anodic oxidation process in a fluoride-containing electrolyte. The microstructures, chemical compositions, and phases of the self-organized TiO₂ nanotube arrays were analyzed by FESEM, XPS, and XRD, respectively. Hexagonal packing density in TiO₂ nanotube arrays significantly improved after the the multi-step anodic oxidation. The area densities of the hexagonal TiO₂ nanotube arrays increased approximately 3 times from the first to second step in the anodic oxidation steps process (4.9 μm⁻² to 16.4 μm⁻²), but there was no difference between the second and third step (16.4 μm⁻² to 16.0 μm⁻²). The as-anodized TiO₂ nanotube array had an amorphous structure and it transformed to an anatase phase during the annealing process at 450 °C for 1 h. The as-anodized TiO₂ nanotube arrays adsorbed the fluoride, hydrocarbon groups (CH), hydroxyl groups (OH, C-OH), and carboxyl groups (O = C-OH) on their surfaces.     

微等离子体氧化制备TiO2薄膜的结构特性

利用微等离子体氧化方法在纯Ti金属表面生长出一层厚度达20μm的陶瓷氧化膜，并用X射线衍射、扫描电镜初步研究了氧化膜的组织结构和表面形貌。在不同电解质溶液条件下，得到3种不同类型结构组成的氧化膜：单一TiO2的锐钛型结构、TiO2锐钛型 金红石型的混合相结构、单一TiO2金红石结构。TiO2单一的锐钛型结构的氧化膜薄膜比较粗糙，TiO2金红石结构的氧化膜表面比较平滑，而混合相结构陶瓷膜的表面层为疏松的锐钛型结构TiO2，亚表层为金红石结构的TiO2。     

Effect of substrate materials on rutile crystalline orientation in plasma-sprayed TiO2 coatings

TiO2 coatings are of technical importance owing to their promising applications to photocatalytical, electrical, optical and tribological coatings. Thermal spraying process has been widely used to deposit both metallic and nonmetallic coatings. During thermal spraying, spray particle at fully or partially melted condition is projected to a substrate and subsequently flattens, rapidly cools and solidifies. Therefore, a coating in lamellar structure is usually formed as a quenched microstructure. TiO2 coatings were deposited on different substrates through plasma spraying with fused-crushed powder in rutile phase as feedstock to reveal the crystalline orientation in the coatings. XRD results show that the coatings consist of rutile phase with a fraction of anatase phase, and the rutile phase presents a preferable crystalline orientation along [101] direction. It is found that the orientation factors of rutile phase in the thin coatings are significantly influenced by substrate materials. The thick coatings yield the same orientation factors of 0.22 to 0.23 on all substrates in spite of substrate materials. It is considered that the thermal properties of substrate materials are the dominant factors for the preferable crystalline orientation in rutile phase within plasmasprayed TiO2 coating.     

阳极氧化法制备多孔氧化铝模板

采用阳极氧化法,以硫酸为电解液制备了多孔氧化铝模板。讨论了氧化电压和电解液温度对多孔阳极氧化铝膜的孔径的影响。试验结果表明,当氧化时间为6h时,氧化膜厚度达到最大值35．6μm。XRD分析结果证实,多孔氧化铝膜由非晶态的Al2O3组成。     

CdS修饰TiO2纳米管阵列的制备及光催化性能研究

首先通过恒压阳极氧化法在纯钛箔表面制备TiO2纳米管阵列,其次运用电化学沉积法在TiO2纳米管阵列表面修饰CdS颗粒,最后表征其对甲基橙的光催化降解性能.研究表明,通过电化学沉积可以在管阵列表面获得均匀分布的CdS纳米颗粒.TiO2纳米管阵列在经过CdS修饰后,对可见光的吸收范围明显增大;光照2 h后,对甲基橙的降解效率由修饰前的57.1%提高到修饰后的76.4%,COD的去除率也从49%提高到70.6%.     

纯钛表面微弧氧化多孔陶瓷膜的结构特性

采用微弧氧化处理技术和电解液成分的优化设计,在纯钛表面制备了含钙磷的多孔复合陶瓷膜,并考察了陶瓷膜的表面形貌、截面形貌、化学成分、物相构成、生物活性及其与基体的结合强度等特性。研究结果表明:纯钛表面微弧氧化后形成了凹凸不平的多孔陶瓷膜,整个膜层分为表层疏松层、中间过渡层和内部致密层三个区域,总厚度为25～40μm,膜层与基体的界面呈"锯齿状"紧密结合。膜层主要由金红石相TiO2和锐钛矿相TiO2构成;膜层中含有Ca,P,O,Ti四种元素,其钙磷比ω(Ca)∶ω(P)为1.528;膜层中的Ti,Ca,P元素呈梯度分布,由表及里Ti含量逐渐增多,Ca和P含量逐渐减少,O元素分布比较均匀。含钙磷多孔复合陶瓷膜具有良好的生物活性,样品经碱液处理后再在快速钙化溶液(FCS)中浸泡4d即有羟基磷灰石(HA)形成;膜层与基体具有高的结合强度,在450V和600Hz时膜层的临界载荷值高达29.5N。     

有序多孔氧化铝模板及 ZnO 沉积膜的制备与表征

采用二次阳极氧化法制备有序多孔氧化铝模板(AAO),探讨了氧化时间、磷酸溶液浸泡后处理对氧化铝表面形貌的影响。以AAO为模板沉积ZnO薄膜,通过SEM,XRD,EDS,AFM等技术对氧化铝模板及ZnO薄膜进行表征,结果表明,有序多孔层为非晶态氧化铝。研究了以AAO为模板沉积ZnO薄膜作光阳极的染料敏化太阳电池的光电转换性能,得出其转换效率为0.34%。     

Ba0.5Sr0.5TiO3铁电薄膜的微弧氧化制备工艺

用分析纯Ba(OH)2·8H2O和Sr(OH)2·8H2O配制电解液(浓度各为0.2 mol/L),采用微弧氧化技术在工业纯钛板(99.5％)表面原位生成BaxSr(1-x)TiO3铁电薄膜.对不同电流密度、电流频率和反应时间条件下获得的薄膜进行表征,研究了各因素对薄膜物相构成、表面形貌和表面粗糙度的影响.结果表明:所得薄膜均主要由四方相Ba0.5Sr0.5TiO3构成;电流密度为20 A/dm2、电流频率为100 Hz、反应时间为10 min时,所得薄膜最平整、致密、表面粗糙度值最小,且微弧氧化孔洞分布最均匀,测得该薄膜在1 kHz条件下的介电常数为411.3.     

时间参数对复合氧化法制备多孔二氧化钛涂层结构的影响

为了分析微弧氧化时间对复合氧化法(即预氧化和微弧氧化复合法)制备的二氧化钛涂层结构和形貌的影响，采用X射线衍射、SEM及附带的能谱(EDS)对涂层的结构、形貌和元素组成进行了分析，采用MH-3型硬度计对涂层表面的硬度进行了测试。结果表明：微弧氧化时间是影响复合氧化法制备多孔二氧化钛表面涂层形貌、结构、硬度和钙磷原子比的主要因素之一。随着微弧氧化时间的延长，涂层表面的微孔孔径增加，凹凸起伏变得明显，涂层中金红石相增加，锐钛矿相减少，表面硬度增加，钙磷原子比也发生了变化。可控制微弧氧化时间得到结构较为理想的多孔二氧化钛梯度涂层。     

Fraction and wear performances of 7475 aluminium alloy after anodic oxidation

The layer of oxide film was prepared on the surface of 7475 aluminum alloy by anodic oxidation, and the friction and wear performance under different loads were investigated with the friction and wear test. The atomic binding energy spectrum, wear morphologies, surface hardness and residual stress were analyzed with XPS, SEM, hard meter and XRD stress tester, respectively. The results show that the oxide film on the surface is relatively dense after anodic oxidation, existing in the form of Al2O3, and the form of the diffusion type in the interface is contained. The average friction coefficient is decreased after anodic oxidation, indicating the friction performance improving. The wear mechanism of primitive sample is adhesive wear and tear, accompanying with abrasive wear, and the wear mechanism of the sample after the anodic oxidation is abrasive wear, where high surface hardness is the main factor of the wear resistance.     

氧化时间对2A12铝合金阳极氧化膜开裂行为的影响

采用不同阳极氧化时间制备氧化膜,并采用扫描电镜、电子探针、连续性检测、交流阻抗法和盐雾腐蚀试验对阳极氧化膜进行了研究。结果表明,不同阳极氧化时间生成的氧化膜层经热冲击后都会出现非穿透性裂纹;随阳极氧化时间延长,经热冲击后,氧化膜层裂纹密度增大。综合考虑不同氧化时间下制备的氧化膜的开裂行为和耐蚀性变化,阳极氧化30 min制备的膜层在热冲击后具相对较好的防护性能。