阳极氧化法制备纳米级多孔氧化铝膜的研究

比较了电化学抛光前后铝片表面的微观结构,用阳极氧化法制备了纳米级多孔氧化铝膜,用扫描电镜研究分析了氧化铝膜孔的排列规律.结果表明其排列高度有序,呈理想的六方柱形结构.     

阳极氧化法制备有序纳米多孔氧化铝膜的研究

利用电化学阳极氧化的方法,在草酸溶液中,精确控制反应条件,在高纯铝片表面有序生长了纳米多孔氧化铝膜。试验中,分别采用一次阳极氧化和二次阳极氧化方法制备氧化铝膜。利用H3PO4溶液浸泡法对氧化铝膜进行扩孔处理。通过扫描电子显微镜对样品进行表征分析。结果发现,二次阳极氧化制备的氧化铝膜的孔洞分布较一次氧化的更为规则有序,并且孔径大小均匀一致。扫描电镜观察显示,氧化铝膜的扩孔过程可以去掉阻碍层,并调节孔径大小,溶去二次氧化后黏附在氧化层表面的一些杂质,从而使氧化铝模板更为规则有序,孔径均一。这种经过二次阳极氧化和扩孔处理得到多孔阳极氧化铝模板的方法简单,成本较低,可以为后续的纳米材料合成提供高质量的合成模板。     

阳极氧化工艺制备氧化铝模板

多孔氧化铝模板是一种用于制作纳米结构材料的模板.为了制作出理想的模板,采用不同的阳极氧化工艺制备多孔氧化铝模板,通过改变工艺参数研究了模板孔径的变化规律,结果表明,在适宜条件下,纳米级氧化铝模板具有六方紧密堆积柱状结构,在每个六棱柱的中心有一个与膜表面垂直的圆柱孔.在一定范围内,随着氧化电压、电流密度、反应温度、铝片纯度的增加氧化铝模板的孔径也随之增加.     

多孔氧化铝膜的制备与形成机理的研究概况

直流恒压条件下,酸性溶液中铝的阳极氧化会形成多孔阳极氧化铝(AAO)。其孔径为纳米级且分布均匀,纵横比大,是合成一维纳米材料的理想模板。本文综述了AAO的结构模型、制备方法、形成机理及其应用热点。     

纳米多孔阳极氧化铝膜形貌的控制研究

采用38g／L的草酸溶液为电解液,制备了孔洞规则有序,孔径和厚度均一可控的氧化铝模板,并研究了阳极氧化工艺对阳极氧化铝膜形貌的影响。实验结果表明,采用38g／L的草酸溶液作为电解液,经两步法阳极氧化可制得孔径均一,排列规则的多孔阳极氧化铝膜。随着氧化电流密度的升高,氧化膜孔径逐渐增大。电流密度过大,反应放热严重,氧化铝膜孔径均匀性,孔洞形状规则性和有序性都下降。在恒电流密度条件下,氧化膜厚度随着氧化时问的延长呈线性增长,但对氧化铝膜孔径影响较小。     

多孔阳极氧化铝模板制备的研究进展

多孔阳极氧化铝(PAA)模板在制备纳米材料、光谱材料、磁性材料、生物传感材料、太阳能电池材料等领域有着极为广泛的应用。实现多孔阳极氧化铝模板的孔径、孔间距、氧化层厚度等参数的可控制备是获得最佳性能材料的关键。概述了近年来多孔阳极氧化铝模板制备的研究进展,简要介绍了在电化学方法制备条件下各种工艺因素对模板形貌的影响,并综述了利用多孔阳极氧化铝作为模板合成纳米材料的几种方法。     

多孔阳极氧化铝模板的制备及其光学特性研究

采用二次阳极氧化法获得分布均匀、有序的纳米多孔阳极氧化铝模板（PAAT），对其形貌、相结构及光学性能进行了表征和分析。光吸收测试发现多孔阳极氧化铝模板在250nm处有一个吸收峰，可见光区是透明的。光致发光测试表明多孔阳极氧化铝模板在450-550nm之间有一个较宽的蓝色发光带，发光峰在460nm左右。     

多孔阳极氧化铝膜在纳米功能材料制备中的应用

纳米材料具有一系列不同于块体材料的新异特性，在许多领域都有着广阔应用前景。阳极氧化铝膜具有独特的多孔结构，可作为制备各种纳米功能材料的模板，因而在纳米功能材料制备中占有重要地位。本文综述了多孔阳极氧化铝模板的结构特征、制作方法及由模板合成法制备的多种纳米功能材料的研究与应用现状，并介绍了模板及纳米功能材料的常用表征手段。     

无阻挡层多孔阳极氧化铝膜板的制备

提出一种在中性的KCl溶液中用多孔阳极氧化铝作阴极,通过电解在阴极产生OH-腐蚀阻挡层,制备无阻挡层氧化铝模板的新方法.用扫描电镜对模板进行了表征.结果表明,在草酸溶液中,制得的氧化铝模板孔径为70～80nm,孔间距为130nm,孔密度约8×109/cm2,这种方法去阻挡层不扩大模板孔径,不影响纳米孔的纵横比.无阻挡层的氧化铝模板适合于直流电沉积和无电沉积金属纳米材料.     

铝箔多孔阳极氧化铝膜的低温制备及其电化学性能

以多孔阳极氧化铝(AAO)膜制备纳米材料时降低AAO膜孔径至关重要,降低电压无法达到要求,而降低氧化温度可实现这一目标。在0.4 mol/L H3PO4溶液中加入70%～80%(体积分数)1,3-丙三醇(PDO),于-10～10℃下恒压110 V阳极氧化1 h制备了多孔阳极氧化铝(AAO)膜,并在0.50 mol/L H3BO3和0.05mol/L Na2B4O7溶液中于20℃下以0.5 mA/cm2进行填孔后处理。利用SEM,EDS,XRD分析了AAO膜的表面形貌与组成,并对AAO膜填孔前后的极化曲线和交流阻抗谱进行了测试。结果表明,膜孔径随氧化温度降低而降低,80%PDO,10℃所得AAO膜的成分包括65.94%(质量分数,下同)Al,12.79%C,20.29%O和0.98%P;随氧化温度升高和PDO含量下降,AAO膜的稳定电流密度增大;随氧化温度升高,膜阻挡层厚度增大;填孔试验前AAO膜只存在一个阻挡层的相位角峰,填孔后出现两个峰,中高频段体现封闭的阻挡层特性,低频段体现的是多孔层封闭部分的特性。     

高度有序多孔阳极氧化铝模板的制备

为了得到纳米孔排列高度有序的多孔阳极氧化铝模板,以0.3 mol·L-1的草酸为电解液研究了模板的制备工艺.采用场发射扫描电子显微镜(FE-SEM)对多孔氧化铝模板的表面形貌进行表征,X射线衍射分析高纯铝及氧化膜的结构.实验结果表明,铝基体不经过高温退火处理,同样能够得到高度有序的氧化铝膜,简化了多孔氧化铝膜的制备工艺.分别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形貌及孔径的影响,并对一步法和两步法制得的多孔氧化铝膜进行比较,结果表明,两步阳极氧化法制备的多孔氧化铝模板的有序性优于一步氧化法.XRD分析证实,多孔氧化铝膜由非晶态的Al2O3组成.     

硫酸中阳极氧化制备Al2O3多孔模板的BPANN模拟

采用24组硫酸阳极氧化多孔膜的样本数据建立BP神经网络模型,得到了多孔膜孔有序度与硫酸阳极氧化参数之间的最优关系,经检验该模型的预测结果与实测结果相一致.表明BPANN 是硫酸阳极氧化制备多孔膜孔有序度的较好的预测模型.     

Fabrication of novel porous anodic alumina membranes by two-step hard anodization

Porous anodic alumina (PAA) membranes with highly ordered hexagonal cells and a novel pore structure have been fabricated by two-step hard anodization in a H(2)SO(4)-Al(2)(SO(4))(3)-H(2)O system at 40 and 50?V, giving average cell diameters of 77 and 96?nm, respectively. There are several tiny pores embedded in each big shallow pore on the top of the membranes, and there is only one pore in one cell at their bottom. The cells on both sides of the membranes present almost the same periodic arrangement. In order to explore the formation of the novel pore structure, PAA membranes fabricated at different current densities (30-200?mA?cm(-2)) are obtained by maintaining a constant voltage at 40?V. The experimental results show that the interpore distance is not only dependent on the anodization voltage, but is also influenced by the current density, which means that the pore structure of PAA membranes fabricated by hard anodization can be accurately designed and controlled by adjusting the anodization voltage and current density simultaneously.     

Formation of complex anodic films on porous alumina matrices

The kinetics of growth of complex anodic alumina films was investigated. These films were formed by filling porous oxide films (matrices) having deep pores. The porous films (matrices) were obtained voltastatically in (COOH)₂ aqueous solution under various voltages. The filling was done by reanodization in an electrolyte solution not dissolving the film. Data about the kinetics of reanodization depending on the porosity of the matrices were obtained. On the other hand, the slopes of the kinetic curves during re-anodization were calculated by two equations expressing the dependence of these slopes on the ionic current density. A discrepancy was ascertained between the values of the calculated slopes and those experimentally found. For this discrepancy a possible explanation is proposed, related to the temperature increase in the film, because of that the real current density significantly increases during re-anodization.     

Investigation on highly ordered porous anodic alumina membranes formed by high electric field anodization

A simple and cost effective method for fabricating long-range ordered porous anodic alumina (PAA) membranes is presented, which explores a self-ordering regime with controllable interpore distances over a large scale (300–360 nm). The cohesive force at the hemi-spherical scallop/cell wall (HS/CW) interface is weaker than the other locations. When the PAA membranes were immersed in H₃PO₄ solution, regular cheese-like hexagonal patterns have been propagated at the cell boundaries. With increased etching time, numerous pores were observed at triple points where three cells met. The distinct fracture and etching behaviors in PAA can be ascribed to the intense ionic transport accompanied by the volume expansion in the barrier region under high electric field.     

A simple one-step anodising method for the synthesis of ordered porous anodic alumina

Porous anodic alumina (PAA) has been produced on aluminium substrate by single-step anodising at 50?V in 0.3?M oxalic acid at 15°C for 60?min. The highly ordered pore and cell structure was achieved by subjecting the PAA to oxide dissolution treatment in a mixture of chromic and phosphoric acids. The nanostructure prior and post-oxide dissolution treatment was examined under scanning electron microscope. It was found that the oxide dissolution treatment improves the regularity of the cell and pore structure significantly. Uniform closely packed honeycomb structure of PAA is obtained. The uniformities of pore diameter and interpore distance are also enhanced. Compared to the PAA prior treatment, it was noticed that the pore diameter of the post-treatment PAA increases.