高度有序多孔阳极氧化铝制备工艺的研究

影响多孔阳极氧化铝(porous anodica lumina,PAA)形貌及结构等的因素有很多,如抛光铝片的表面粗糙度、电解液温度、氧化电压、氧化时间、搅拌速率等。本文采用二次阳极氧化法,以草酸为电解液,研究了高度有序AAO模板制备过程的主要工艺条件,并采用扫描电子显微镜对模板的形貌进行表征。结果表明,在电解液温度为12℃,氧化电压为40V能够得到高度有序的、孔径为80nm左右的多孔阳极氧化铝膜。     

多孔阳极氧化铝模板制备工艺的研究

以硫酸溶液为电解液,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、阳极氧化电压和阳极氧化温度对多孔阳极氧化铝模板形貌、孔径和孔间距的影响,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氧化铝膜的通孔剥离,获得具有较大面积、韧性较好的通孔多孔阳极氧化铝模板.     

孔间距和孔径连续可调的PAA模板的制备

在磷酸溶液中以二次阳极氧化制备的多孔阳极氧化铝(PAA)模板存在孔的规整低的缺点,文中提出了在磷酸/草酸混合溶液中采用二次阳极氧化法制备高规整(PAA)模板,利用图像处理软件(Image-Pro plus)对PAA膜的扫描电镜图进行分析处理,定量研究了阳极氧化电压、草酸含量和扩孔时间对PAA模板的孔径和孔间距的影响。由实验结果可知,在质量分数1%磷酸溶液中加入0.03 mol/L草酸溶液作为阳极氧化电解液,阳极氧化电压可以达到200 V。通过调节草酸添加量和阳极氧化电压可以得到孔间距在345—498 nm范围内高规整PAA模板。通过改变扩孔时间可以获得孔径在140-400 nm范围内高规整PAA模板,并且孔径与扩孔时间呈正线性相关关系,相关系数为0.99。这种高规整孔径、孔间距连续可调的PAA模板能够被用于制备规整金属纳米线阵列、纳米管阵列和高分子纳米柱等材料。     

纳米有序多孔阳极氧化铝制备方法的研究进展

多孔阳极氧化铝(PAA)模板以六角形元胞紧密排列,孔径大小可调,且化学稳定性好,近年来在催化、传感、过滤和仿生等领域受到了越来越多的关注。PAA模板的制备一直以来都是研究的热点,因为模板的结构和性质直接影响其应用的效果。本文在简要介绍了自组织有序多孔阳极氧化铝的特点及影响因素的基础上,较为全面地综述了制备自组织PAA模板不同方法的研究进展,包括温和阳极氧化法、强烈阳极氧化法、脉冲式阳极氧化法和周期性阳极氧化法。具体分析了不同阳极氧化方法的特点以及各自得到的氧化铝模板不同的特点和应用范围,说明了氧化电压、氧化温度和电解液种类在制备PAA模板时对其孔洞尺寸的重要作用,最后对阳极氧化铝膜的发展前景进行了展望。     

AAO模板制备条件的研究

为了得到高度有序的多孔阳极氧化铝(anodic aluminum oxide,AAO)模板,本文分别研究氧化电压、氧化温度、电解液种类、电解液浓度等影响因素对阳极氧化铝模板形成的影响,利用扫描电镜( SEM)观察不同条件下氧化铝膜的微观结构,从而得出了阳极氧化铝模板的最佳制备工艺范围:温度0～20℃,氧化电压35～50...     

高度有序多孔阳极氧化铝模板制备工艺研究

在酸性电解液中,用二次阳极氧化法制备得到了高度有序的多孔阳极氧化铝(PAA)模板。采用金相显微镜观察了铝箔退火前后的表面形貌,并结合扫描电镜对多孔氧化铝薄膜的结构进行了表征。研究表明,高度有序多孔阳极氧化铝膜的制备依赖于铝箔是否经过预处理、氧化电压的大小、温度的稳定性和电解液的选择等。     

多孔氧化铝模板的制备及应用

以磷酸溶液为电解液、以高纯铝为阳极,采用两步阳极氧化法制备氧化铝模板。扫描电子显微镜(SEM)对其表面形貌分析表明,氧化铝膜为多孔结构,膜孔径随着阳极氧化电压的增大而不断增大。对阳极氧化电流密度变化分析证实,铝的阳极氧化经历了三个阶段:阻挡层的生成、多孔层的形成和多孔层的稳定生长。以制备的氧化铝膜为阴极、锌片为阳极,以硝酸锌和硼酸的混合液为电解液,采用交流电沉积方法制备了针状氧化锌纳米线。     

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箔退火后表面上的晶界,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、氧化电压和电解液等的选择。     

阳极氧化电压对多孔氧化铝膜生长过程的影响

以草酸溶液为电解质,采用两步电化学阳极氧化法制备了氧化铝有序多孔膜,研究了阳极氧化电压对多孔膜生长过程及形貌的影响. 结果表明,电流密度、生长速率及孔径、孔间距随电压的升高而增大,而膨胀因子与电压呈线性关系. 氧化铝膜的孔隙率保持在12%左右,与电压基本无关.     

多孔氧化铝膜制备金纳米线阵列

利用二次阳极氧化法制备了多孔氧化铝模板,用交流电化学沉积方法成功地在模板孔道内制备了Au纳米线。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)对Au纳米线的形貌、晶体结构进行了研究。结果表明,模板的孔径均匀,孔道平直。Au纳米线均匀分布在PAA纳米孔中,直径与PAA孔径一致,约50 nm,且为多晶结构。     

铝阳极氧化多孔膜的制备和应用研究

介绍了以高纯铝为原料采用二次阳极氧化技术制备铝阳极氧化多孔膜的工艺条件，并对以其作为功能膜进行模板组装方面的应用作了研究。     

Preparation of anodic aluminum oxide (AAO) nano-template on silicon and its application to one-dimensional copper nano-pillar array formation

Anodized aluminum oxide (AAO) nanotemplates were prepared using the Al/Si substrates with an aluminum layer thickness of about 300 nm. A two-step anodization process was used to prepare an ordered porous alumina nanotemplate, and the pores of various sizes and depths were constructed electrochemically through anodic oxidation. The optimum morphological structure for large area application was constructed by adjusting the applied potential, temperature, time, and electrolyte concentration. SEM investigations showed that hexagonal-close-packed alumina nano-pore arrays were nicely constructed on Si substrate, having smooth wall morphologies and well-defined diameters. It is also reported that one dimensional copper nanopillars can be fabricated using the tunable nanopore sized AAO/Si template, by controlling the copper deposition process.     

Nanotip fabrication by Anodic Aluminum Oxide templating

We demonstrate a novel approach to fabricate a gold nanotip array using an Anodic Aluminum Oxide (AAO) template prepared by anodizing the aluminum in two acids with increasing anodization voltage, which results in the nanopore diameter being increased along the AAO channels. The thick barrier layer formed at the bottom of the AAO template can be removed without affecting the apex diameter by forming a thick apex region in the initial stage. Finally, gold is electrodeposited into the template and a gold nanotip array with apex and base diameter of 21 nm and 210 nm, respectively can be achieved. The structure of the nanotip array can be varied by manipulating the dimensions of the AAO channels by controlling the applied voltage together with the anodization time. Using this method, the material choice of nanotip array can be varied easily.     

多孔氧化铝模板法制备取向碳纳米管阵列的研究进展

利用化学气相沉积技术在多孔氧化铝模板上可以制备取向碳纳米管阵列。通过调节阳极氧化参数可以改变模板的孔结构,进而可控制碳纳米管在孔道中生长的形貌。用这种方法制备的碳纳米管的直径、长度和密度可以选择性控制,这将有利于研究碳纳米管的性质和它在电化学及其他领域的应用。介绍了多孔氧化铝模板的形成原理以及碳纳米管在多孔氧化铝模板上的生长机理,讨论了阳极氧化条件、催化剂和气相沉积温度对碳纳米管特性的影响,并指出了这种技术中一些需深入研究的问题。     

Morphological and chemical characterization of highly ordered conical-pore anodic alumina prepared by multistep citric acid anodizing and chemical etching process

Highly ordered, conical-pore anodic alumina (AAO) membranes with interpore distance (D _c ) between ca. 530 and 620 nm and thickness ranging between 2.4 and 7.8 μm, were produced. In the fabrication process aluminum surface was first pre-patterned by the anodization in etidronic acid solution. Then, the regular arrays of Al concaves were used as nucleation sites to grow AAO during the second anodization, which was carried out in highly concentrated citric acid solution (20 wt%) and at relatively high temperature (33–35?°C). The conical pore shape was engineered by a multistep process combining anodization in the citric acid electrolyte and the subsequent chemical pore broadening in phosphoric acid solution. The morphological analyses has revealed that the geometrical parameters of the Al concaves were successfully transferred to the AAO membranes. Furthermore, FTIR spectra analysis confirmed that the electrolyte species, such as phosphonate and citric ions, are being embedded into the AAO framework during the anodization. The graded-index structure formed in AAO can be used for a production of antireflective coatings operating in a broad spectral range.     

Structural features of self-organized nanopore arrays formed by anodization of aluminum in oxalic acid at relatively high temperatures

Anodic aluminum oxide (AAO) membranes with a highly ordered nanopore arrangement typically serve as ideal templates for the formation of various nanostructured materials. A typical procedure of the template preparation is based on a two-step self-organized anodization of aluminum carried out at the temperature of about 1-3 °C. In the current study, AAO templates were fabricated in 0.3 M oxalic acid under the anodizing potential range of 30-65 V at a relatively high electrolyte temperature ranging from 20 to 30 °C. Due to a high rate of porous oxide growth, about 5-10-fold higher than in low-temperature anodizing, the process of the template fabrication can be shorten significantly. Similarly to the low-temperature anodization, the best hexagonal pore arrangement is observed for samples anodized at 40 V. With a prolonged duration of the first anodizing step the order degree of triangular nanoporous lattice, observed after the second anodization, improves considerably. The effects of the anodizing potential and the process duration on the structural features of porous anodic alumina such as: pore diameter (D_p), interpore distance (D_c), porosity (P), pore density (n) and anodizing ratio (B_U) were investigated in details at various temperatures. The obtained results were compared with theoretical predictions and data reported in the literature.     

Tailoring the nanostructure of anodic aluminum oxide cladding on optical fiber

We report a comprehensive investigation of fabricating nanostructured anodic aluminum oxide (AAO) cladding on optical fiber. We show that the pore size and interpore distance in the AAO cladding with pore channels vertically aligned to fiber surface can be readily controlled by applied voltage, the type, and concentration of electrolytic acid during anodization of aluminum‐coated optical fiber. The structural characteristics of the AAO cladding were examined by scanning electron microscopy (SEM) and analyzed using ImageJ software. Processing maps correlating AAO growth and anodization parameters were established. Compared to planar AAO growth on aluminum foil, higher growth rate as well as larger pore diameter and interpore distance were observed for AAO cladding formation on optical fiber under identical anodization conditions due to circumferential tensile stress in the AAO growth front at the convex AAO/aluminum interface. This tensile stress also contributed to radial cracking of the AAO cladding upon exceeding some threshold thickness.     

Fabrication of enhanced anodic aluminum oxide performance at room temperatures using hybrid pulse anodization with effective cooling

Conventional anodic aluminum oxide (AAO) template was performed using potentiostatic method of direct-current anodization (DCA) on costly high-purity (99.997%) aluminum foils at low temperatures of 0–10 °C to avoid dissolution effects which occurred frequently at room temperatures (RT) of 20–30 °C. In this paper, we show the hybrid pulse anodization (HPA) method with pulsing normal-positive and small-negative potential differences at RT for enhancing performance of AAO structure for both the cheap low-purity (99%) and costly high-purity (99.997%) aluminum foils. The HPA mainly takes advantages of effective cooling that arise from the nearly zero cathodic current and high-thermal-conductivity liquid electrolyte on the foils. The HPA is different from the traditional pulse anodization with alternating both high and low positive potential differences (/currents) or both one-positive and one-zero potential differences. The HPA not only merits manufacturing convenience and cost reduction but also promotes pore distribution uniformity of AAO at severe conditions of cheap low-purity Al foils and relatively high room temperature. The pore distribution uniformity can be improved by HPA in a suitable duration compared with the DCA. Very good AAO distribution uniformity (91%) was achieved in high-purity aluminum foil by HPA because it can suppress the Joule's heat to diminish the dissolution reaction. The evolution of AAO distribution uniformity for both the HPA and DCA on Al foil purities and process durations were comparatively investigated.