纳米氧化铝有序多孔膜制备工艺研究

为了获得大面积有序孔排列以及不同孔径的氧化铝膜,采用二次阳极氧化法可制备大面积有序铝阳极氧化多孔(AAO)膜,着重研究氧化电压、氧化时间、电解液浓度以及扩孔时间对AAO膜孔径大小、膜层厚度和形貌结构的影响,用X射线粉末衍射(XRD)仪进行物相分析,利用扫描电子显微镜(SEM)表征多孔膜的形貌.结果表明,在700 ℃以下条件下AAO膜以无定形态存在,经800 ℃退火后无定形氧化铝转化为γ-Al2O3,多孔膜随电压和电解液浓度增加而增大,经H3PO4溶液扩孔后可获得较大孔径模板,扩孔时间与孔径变化呈近似线性关系.为满足应用需求的AAO膜的制备提供了依据.     

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。     

草酸阳极氧化工艺对氧化铝模板孔径的影响

为了寻找出草酸氧化工艺和扩孔工艺对制备的氧化铝模板孔径大小的影响规律,本文采用高倍扫描电镜观察定量研究了纯铝草酸阳极氧化几种氧化工艺参数对制备的氧化铝模板纳米孔径大小的影响,并对氧化铝模板的扩孔工艺进行了研究.结果表明,随着草酸浓度、氧化电压、氧化温度的升高和氧化时间的延长,制备的氧化铝模板的孔径也随着增加;在扩孔溶液浓度、温度保持一定时,随着浸泡时间的延长,氧化铝模板的孔径会逐渐增大.本研究结果为模板合成有序纳米阵列结构提供了参考.     

用低纯度铝制备AAO模板及其结构研究

在0.3mol/dm3草酸溶液中,通过不同纯度铝的恒电位二次阳极氧化制备了纳米孔氧化铝模板,并用场发射扫描电子显微镜(FE-SEM)和原子力显微镜(AFM)观察模板结构.实验结果表明,一次氧化除膜后低纯度铝基体表面呈现较为规则的六边形结构,这种蜂巢结构有利于二次氧化过程中获得有序度更高的纳米孔模板.低纯度铝制备的模板表面被晶界分隔为微小的区域,只是在较窄区域内才出现六边形规则排列的纳米孔.恒电位40V时所得模板经扩孔处理后,孔径由35nm增大到100nm左右,且孔径大小几乎一致.从纳米孔的有序度来看,由低纯度铝制备模板还需要进一步优化阳极氧化参数.     

纳米阵列阳极氧化铝模板的制备及其形成机理

多孔阵列阳极氧化铝模板为合成大面积的准一维纳米丝和纳米管微阵列提供了一种有效的载体.采用二次氧化法,制备了孔径在30～40 nm之间的纳米阵列氧化铝模板,分析了纳米阵列阳极氧化铝模板形成的热力学原理、动力学原理及孔的形成机理.采用扫描电子显微镜(SEM)对其形貌进行了表征,通过扩孔试验得到了孔径与扩孔时间的关系.用XRD衍射仪对纳米薄膜的成分和形态进行了分析,证明了制备的氧化膜是非晶态的.     

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.     

铝阳极氧化膜的扩孔处理

铝多孔质阳极氧化膜是制备自润滑阳极氧化铝的基础，其技术关键之一是在不破坏氧化膜结构与性能的前提下，尽可能扩大微细孔的孔径。本文用透射电镜（ＴＥＭ）、显微硬度仪、ＳＲＶ摩擦实验机等设备，系统考察了草酸溶液中生成铝阳极氧化膜的微观多孔质结构以及经扩孔处理后该氧化膜多孔质结构的变化和对氧化膜机械性牟的影响，重点探讨了扩孔处理对氧化膜表面硬度和耐磨性的影响，并由此确定了最佳扩孔时间及最佳孔径，为制备纳米量     

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.     

磷酸中铝阳极氧化及扩孔对膜层的影响

为进一步了解磷酸扩孔对铝阳极氧化铝膜的影响,将铝在磷酸介质中恒压阳极氧化,把氧化后的铝片放入5%的磷酸溶液中扩孔5～8 min,通过扫描电镜(SEM)观测了阳极氧化膜的形貌和结构特征,结果表明:氧化膜上的微孔分布均匀,孔径大小基本相同,平均孔径约为150 nm,孔密度约为2.5×109 个/cm2,柱状孔之间相互平行.氧化膜经酸液扩孔,可使其孔形由不规则圆形变成规则圆形,随着扩孔时间的延长,阳极氧化膜的孔径呈近似线性增大,但达一定时间后,孔形不再为规则圆形,而且伴有连孔现象出现.因此本试验条件下,扩孔时间以6～7 min为宜.     

氧化铝阵列模板制备及其影响因素研究

经预处理的铝箔,分别以不同浓度硫酸和草酸为电解液,在不同阳极氧化时间、电压下,用二步阳极氧化法制备多孔有序阳极氧化铝阵列模板,用透射电镜对其形貌和结构进行了表征,用测厚仪测量了氧化膜厚度.研究结果表明,电解液种类、阳极氧化时间、电压等因素对氧化铝阵列模板外观、膜厚、孔径、孔排列有序度都有不同程度的影响.     

One-step anodization fabrication and morphology characterization of porous AAO with ideal nanopore arrays

A fabrication method for one-step anodization of an anodic aluminum oxide (AAO) template with nanopore arrays using pretreated high purity aluminum foil is reported in this article. Morphology of the AAO was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Results showed that porous AAO with ideal nanopore arrays can be fabricated by one-step anodization fabrication technology on high purity aluminum foil which had been anodized at 45?V direct current (DC), in 0°C, 0.5?M H₂C₂O₄ solution for 48 hours. The average pore diameter and the interpore distance were 80?nm and 120?nm, respectively. Nanopores in porous AAO had very narrow size distribution and were arranged into hexagonal array. The formation mechanism of nanopore arrays in porous AAO is discussed. Porous AAO with ideal nanopore arrays provide an ideal template for preparation of many one-dimensional nanomaterials. One-step anodization of AAO is a simpler procedure and more applicable in industrial application than the previous two-step anodization technology.     

Variation of nanopore diameter along porous anodic alumina channels by multi-step anodization

In order to form tapered nanocapillaries, we investigated a method to vary the nanopore diameter along the porous anodic alumina (PAA) channels using multi-step anodization. By anodizing the aluminum in either single acid (H3PO4) or multi-acid (H2SO4, oxalic acid and H3PO4) with increasing or decreasing voltage, the diameter of the nanopore along the PAA channel can be varied systematically corresponding to the applied voltages. The pore size along the channel can be enlarged or shrunken in the range of 20 nm to 200 nm. Structural engineering of the template along the film growth direction can be achieved by deliberately designing a suitable voltage and electrolyte together with anodization time.     

水解沉积--阳极氧化法形成Al-Ti复合氧化膜

通过含钛无机盐的水解沉积及高温热处理,铝电极箔表面形成高介电常数氧化物———TiO2 膜层,然后在己二酸铵溶液中恒电流阳极氧化,形成 Al Ti复合氧化膜。AFM观测了含钛无机盐水解沉积过程中,铝电极箔表面形貌的变化。在铬酸和磷酸的混合溶液中测试了氧化膜的耐电压随溶解时间的变化。通过SIMS检测了复合氧化膜中 Al3 、Ti4 的强度随溅射时间的变化。膜溶解试验及 SIMS 检测结果表明Al Ti复合氧化膜由 3 层组成,外层和中间层为 Al、Ti、O不同配比的混合物,内层则为纯的 Al2O3。铝电极箔比容随氧化膜耐电压的变化关系曲线表明,60V耐电压下,Al Ti复合氧化膜的比容提高率为51%。     

合成和表征NiFe2O4纳米线阵列

采用真空灌注结合溶胶-凝胶和氧化铝模板法,在多孔氧化铝模板中制备了平均直径为50 nm的NiFe2O4纳米线阵列.X射线衍射结果显示所制备的纳米线是纯相的NiFe2O4纳米线,透射电镜和电子衍射的结果显示已制备的纳米线是多晶的且表面光滑,场发射扫描电镜图片显示纳米线是大面积且平行有序的、纳米线的长度和所用的氧化铝模板的厚度相当.磁测量的结果显示此纳米线阵列有形状各向异性,同块状材料相比矫顽力有所增强.对纳米线的生长机理做了简单的讨论.     

Template assisted synthesis of SnO<Subscript>2</Subscript> nanorods by immerse and filtration technique,vacuum and drop setting

Honeycomb-shaped and ordered arrays of nanopore AAO template with a uniform pores size was produced utilizing a two-step an anodization process. Highly ordered SnO₂ nanorods arrays have been selectively fabricated via a convenient (immerse and filtration) technique and (vacuum and drop) setting using anodic aluminum oxide (AAO) as a hard template. The morphology of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (FESEM), and Energy-dispersive X-ray spectroscopy (EDX) techniques. The optical characterizations were examined by UV-VIS and Photoluminescence (PL). Scanning microscopy images indicate that the SnO₂ nanorods are relatively uniform with the outer diameter matching well with the pore diameter. XRD and EDX indicated that these polycrystalline SnO₂ nanostructures with well-defined composition were obtained.     

Preparation of metallic nanopore arrays using template-guided electrochemical etching

For the first time, preparation of metallic nanopore arrays using anodic aluminum oxide membrane template-guided electrochemical etching technique was reported. The procedure consists of four main steps, sputtering of a conductive layer, thickening of the conductive layer by electroplating, template-guided etching of the electroplated metal layer along the nanopores in the anodic aluminum oxide, and removing of the anodic aluminum oxide template. Scanning electronic microscopy, X-ray diffraction and X-ray photoelectron spectroscopy were used for characterization of the Au nanopore arrays, which proved that the nanopores in the Au matrix were generated due to template-guided electrochemical etching. This method can be used for preparation of double-layered nanostructure with through nanopores penetrating the top insulating layer and the bottom conducting layer.     

End-closed NiCoFe-B nanotube arrays by electroless method

A novel approach is obtained during the fabrication of NiCoFe-B nanotube arrays via electroless method. Porous anodic aluminum oxide (AAO) templates fabricated by anodization of aluminum foil were sensitized using PdCl₂ solution and immersed into electroless plating baths at room temperature to produce nanotube arrays. Compositional and morphological properties of the nanotube arrays are characterized. Results indicates the formation of end-closed nanotubes with the dimension of 100-130 nm in outside diameter, which is determined by the pore size of the AAO template, and about 15 nm in thickness of tube walls. The possible formation mechanism of end-closed metallic nanotube arrays is discussed.     

用AAO模板法制备硅纳米管

先用二步阳极氧化法制备纳米孔平均孔径约为100 nm的Al/Al_2O_3(AAO)模板,再以AAO为模板用溶胶-凝胶法合成管径约为60-80 nm的硅纳米管,并用扫描电镜和透射电镜观察了硅纳米管的形貌。结果表明,AAO模板的孔径分别随着二步阳极氧化法中电解温度、氧化电压、硫酸和草酸混酸浓度的增大而增大,硅纳米管的形成与硅烷溶胶的嵌入方法、凝胶形成时间和温度有较大的关系。