多孔阳极氧化铝膜的制备及电化学阻抗谱分析

在8℃、40V直流电压、0.3 mol/L的草酸电解液中,采用两步阳极氧化法用高纯度铝箔制备多孔阳极氧化铝（AAO）膜。用场发射扫描电子显微镜观察多孔阳极氧化铝膜的形貌。采用电化学交流阻抗法测量多孔阳极氧化铝膜制备过程中一次氧化和二次氧化后的电化学阻抗谱。试验结果表明,所制备的多孔阳极氧化铝膜为高度有序排列的纳米孔洞阵列。根据试验得到的电化学阻抗谱建立了R（QR）（QR）等效电路,该等效电路能较好地表征多孔阳极纳米氧化铝膜的电化学特性,进而找到了等效电路中电学元件与草酸电解液、多孔氧化铝膜的特性及界面电荷转移的关系。该研究有助于研究多孔阳极氧化铝膜的生长过程及形成机理。     

纳米多孔氧化铝膜的制备与结构表征

采用二次阳极氧化法,以草酸为电解液,制备纳米多孔氧化铝膜。利用扫描电镜、原子力显微镜和X射线衍射仪对氧化铝薄膜的微观形貌和相组成进行了表征,研究了二次阳极氧化法制备纳米多孔氧化铝膜的过程和成膜机理。结果表明:二次阳极氧化制备的纳米多孔氧化铝膜为非定型态,所得孔洞排列规则且分布均匀,平均孔径约为29 nm,孔密度为1.74×1010个/cm2。纳米多孔氧化铝膜的形成经历了阻挡层形成、微孔层形成和多孔层形成与长大等阶段。     

高质量氧化铝模板的制备及其研究

以5%磷酸为电解液,通过阳极氧化高纯铝片制得了有序性较高的多孔氧化铝模板,结合扫描电镜(SEM)对其结构和行貌进形观察和表征.研究了氧化铝模板的制备工艺,还讨论了氧化铝膜的形成过程,最后比较了一次阳极氧化和二次阳极氧化获得的样品的多孔结构,认为低温下采用二次阳极氧化法可以获得很好的多孔氧化铝模板.     

高度有序多孔氧化铝模板影响因素的研究

在酸性电解液中,用阳极氧化法制备得到了多孔阳极氧化铝(anodic aluminum oxide,AAO) 模板.用金相显微镜观察了铝片表面上的晶界,并结合扫描电镜对多孔氧化铝薄膜进行了观察和表征.研究了影响多孔氧化铝模板孔洞有序性的关键性因素.实验结果表明,多孔阳极氧化铝膜的有序度依赖于铝箔预处理、电极材料、氧化电压和电解液类型及温度等因素.     

预处理及氧化工艺对阳极氧化铝膜结构有序度的影响

采用硫酸阳极氧化工艺制备了多孔阳极氧化铝膜,采用扫描电子显微镜对多孔氧化铝膜的形貌进行表征。分别讨论了高温退火和二次氧化对多孔阳极氧化铝膜多孔结构的有序度的影响。试验结果表明,高温退火和二次氧化对提升阳极氧化铝膜的结构有序度起了很大作用。     

《电镀与精饰》2009年第11期摘要

多孔阳极氧化铝模板制备工艺的研究以硫酸为电解液,采用二次阳极氧化工艺制备高度有序的多孔阳极氧化铝模板。研究了电解液浓度、阳极氧化电压和制备温度对多孔阳极氧化铝模板形貌和孔洞尺寸的影响,并以高氯酸和丙酮的混合溶液为电解液,利用第三次阳极氧化,一步实现了多孔阳极     

制备纳米材料的多孔型氧化铝膜板的阳极氧化工艺研究

多孔型阳极氧化铝膜是制备纳米材料的理想模板。以草酸为电解液研究了高纯铝的阳极氧化工艺,采用扫描电镜对多孔型阳极氧化铝膜的表面及断面形貌进行表征。讨论了阳极氧化电压和电解液温度对多孔阳极氧化铝膜的孔径及孔密度的影响。对氧化膜厚度的测定结果表明,当氧化时间为7 h时,氧化膜厚度达到最大值36μm。     

低电压下多孔阳极氧化铝膜的制备

选取草酸溶液电解液,采用低压恒压法与二次阳极氧化工艺制备了多孔阳极氧化铝膜(AAO)。借助扫描电镜(SEM),观察了电解液浓度和氧化时间对多孔阳极氧化铝膜的形貌、孔径和孔间距的影响,得到电流随时间的变化曲线。研究了多孔阳极氧化铝膜层厚度与电流密度及氧化时间之间的关系,探讨了多孔阳极氧化铝膜形成机理,优化了阳极氧化制备工艺。结果表明:利用低压恒压法,在氧化电压18 V,氧化时间12 h,氧化液浓度0.6 mol/L时,可制备孔径均匀、高度有序的多孔阳极氧化铝膜。     

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。     

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%。     

阳极氧化铝膜的表面接枝改性及润湿行为

目的通过对阳极氧化铝膜(AAO)表面化学接枝甲基丙烯酸甲酯,改变其表面的粗糙度和分子结构,从而实现AAO膜表面润湿行为的可控。方法采用二步阳极氧化法制备六方柱形的多孔AAO膜,结构高度有序,并对AAO膜表面进行硅烷化(KH-570)处理,采用活性聚合的方法在其表面接枝上甲基丙烯酸甲酯。采用原子力显微镜(AFM)、X射线衍射仪(XRD)和接触角测定仪对AAO膜及改性后的AAO膜进行了结构表征和润湿行为研究。探讨了阳极氧化的工艺条件及接枝甲基丙烯酸甲酯对AAO膜的形貌和润湿性能的影响。结果 AAO膜孔径在100 nm左右,六边形孔洞分布均匀,并且六边形孔洞垂直于AAO膜表面,孔洞与孔洞平行,通过对其表面接枝甲基丙烯酸甲酯,使得AAO膜的表面水接触角先增大后减小。结论 AAO膜表面的润湿行为,可以通过AAO膜表面化学改性和表面粗糙度共同作用而得以调控。     

FRICTION PROPERTIES OF OIL-INFILTRATED POROUS AAO FILM ON AN ALUMINUM SUBSTRATE

1. IntroductionA lum inum and its alloys are used in m any engineering applications because of their highstrength-to-w eightratio and high therm alconductivities.H ow ever,high friction coefficient,poorw earresistance and low seizure load ofalum inum allo…     

Microstructural and Optical Properties of Porous Alumina Elaborated on Glass Substrate

A transparent porous anodized aluminum oxide (AAO) nanostructure was formed on a glass substrate using the anodization of a highly pure evaporated aluminum layer. A parametric study was carried out in order to achieve a fine control of the microstructural and optical properties of the elaborated films. The microstructural and surface morphologies of the porous alumina films were characterized by x-ray diffraction and atomic force microscopy. Pore diameter, inter-pore separation, and the porous structure as a function of anodization conditions were investigated. It was then found that the pores density decreases with increasing the anodization time. Regular cylindrical porous AAO films with a flat bottom structure were formed by chemical etching and anodization. A high transmittance in the 300-900 nm range is reported, indicating a fulfilled growth of the transparent sample (alumina) from the aluminum metal. The data showed typical interference oscillations as a result of the transparent characteristics of the film throughout the visible spectral range. The thickness and the optical constants (n and k) of the porous anodic alumina films, as a function of anodizing time, were obtained using spectroscopic ellipsometry in the ultraviolet-visible-near infrared (UV-vis-NIR) regions.     

Structural features of anodic oxide films formed on aluminum substrate coated with self-assembled microspheres

The structural features of anodic oxide films formed on an aluminum substrate coated with self-assembled microspheres were investigated by scanning electron microscopy and atomic force microscopy. In the first anodization in neutral solution, the growth of a barrier-type film was partially suppressed in the contact area between the spheres and the underlying aluminum substrate, resulting in the formation of ordered dimple arrays in an anodic oxide film. After the subsequent second anodization in acid solution at a voltage lower than that of the first anodization, nanopores were generated only within each dimple. The nanoporous region could be removed selectively by post-chemical etching using the difference in structural dimensions between the porous region and the surrounding barrier region. The mechanism of anodic oxide growth on the aluminum substrate coated with microspheres through multistep anodization is discussed.     

Porous anodic alumina membranes formed by anodization of AA1050 alloy as templates for fabrication of metallic nanowire arrays

The through-hole porous anodic aluminum oxide (AAO) membranes were fabricated by a two-step anodization of the aluminum alloy (AA1050) in 0.3 M oxalic acid at 45 V and 20 °C followed by removal of Al and pore opening/widening procedures. The effect of duration of the second anodizing step on the porous oxide layer thickness and the influence of the pore opening time on structural features of as-prepared membranes were studied in detail. The prepared membranes with a thickness of about 60 μm were used as templates for fabrication of dense arrays of Ag, Au, and Sn nanowires with various aspect ratios by a DC electrochemical deposition process. The successful synthesis of metallic nanowires by simple DC electrodeposition of metals inside the pores of AAO templates fabricated from the AA1050 alloy was reported for the first time. The fabrication costs of nanowire arrays can be reduced by about 500 times when AAO templates, prepared from the AA1050 alloy, are used instead of those usually formed from expensive high purity Al.     

Alumina nanostructures prepared by two-step anodization process

Alumina nanostructures were obtained by two-step anodization process.The porous anodic aluminum oxide(AAO)membranes were anodized in oxalic acid,which was subsequently treated with chemical etching process with 1.0 mol/L sodiumhydroxide solution,or mixed solution of phosphoric acid(6.0%)and chromic acid(1.8%),respectively.Field emission scanningelectron microscopy(FE-SEM)and transmission electron microscopy(TEM)were employed to character the morphology andstructure of the obtained alumina nanostructure.It is found that alumina nanowires are generated in the acidic chemical etchingsolution,while nanotube structures are formed in the alkaline solution.The influence of acid and alkaline solution on aluminamorphologies in the chemical etching process was discussed.     

Linearly joined carbon nanotubes

Linearly joined carbon nanotubes (CNTs) have been fabricated on well-ordered porous anodic aluminum oxide (AAO) nanotemplates prepared by a multi-step anodization and pore widening process. The location and shape of the junctions are very uniform. The electronic properties of the tubes will be affected critically by the junctions. Therefore, one could design CNTs which have specific properties by changing the ratio of the two diameters of linearly joined CNTs. The linearly joined tubes could be used in fabrication of nanoscale electronic devices like field-effect transistor (FET).     

Synthesis of anodic aluminum oxide (AAO) at relatively high temperatures. Study of the influence of anodization conditions on the alumina structural features

Anodic aluminum oxide (AAO) is a well known template for nanofabrication. Structural features of AAO like pore diameter, interpore distance, porosity, pore density can be fully controlled by operating conditions of anodization. Typically, self-organized two-step anodization is carried out at low temperature (below room temperature) and is a time consuming process. There are individual experiments describing anodization at temperatures close to room temperature. In our study, furthermore, a systematic analysis of the anodization condition influence on the nanoporous alumina structural features was done. The anodization temperature was ranging from 35 to 50 °C increasing significantly current density of the processes, which has increased oxide film growth rate. The anodizing potential ranged from 20 to 60 V and time of the anodization steps was 30, 60 or 120 min. The data obtained has shown that the pore diameter increases with potential, temperature and time of anodization, while the interpore distance is influenced solely by the potential. Temperature and time changes do not affect the interpore distance. Porosity is also influenced by potential, temperature and duration of anodization. Pore density is influenced only by the potential. The synthesis of AAO reported here gives possibilities to obtain the AAO templates in a faster and cheaper way, essential for researchers applying anodic alumina as a template.