电子束蒸发法在多孔氧化铝膜上制备银纳米点阵列

采用二步阳极氧化法在草酸溶液中制备了高度有序的多孔阳极氧化铝(Porous Anodic Alumina,PAA)薄膜。以多孔氧化铝薄膜为模板,采用真空电子束蒸发的方法在多孔氧化铝模板上制备出了高度有序的金属银纳米点阵列体系。扫描电镜(SEM)测试结果表明,所制备的金属银纳米点阵列与多孔阳极氧化铝膜的多孔阵列具有完全相同的有序结构,阵列中银纳米颗粒的形状接近球形,其直径大约为70nm,与氧化铝模板的孔径基本一致。研究了高度有序银纳米点阵列的形成过程。     

银纳米有序阵列SERS活性基底的制备及在膀胱肿瘤细胞检测中的应用

以多孔阳极氧化铝(porous anodic alumina,PAA)膜为模板,采用真空电子束蒸镀技术,分别在PAA多孔层以及阻挡层表面形成了银纳米孔和银纳米帽有序阵列表面增强拉曼散射(surface-enhancedRaman scattering,SERS)活性基底,并以膀胱肿瘤细胞作为分子探针,测试和分析了这两种SERS活性基底的表面增强拉曼光谱的特性。结果表明,两种SERS活性基底对膀胱肿瘤细胞的拉曼散射信号均有很好的增强作用。银纳米帽有序阵列SERS活性基底不仅具有较高的SERS增强和荧光猝灭效应,而且不存在与PAA膜中草酸根杂质相关的干扰峰,可获得膀胱肿瘤细胞拉曼散射光谱的更多细节信息。     

含钴阳极氧化铝膜的磁致偏光特性

用电化学法制备了高度有序的多孔阳极氧化铝模板,选用CoSO4溶液为电解液,用交流电化学沉积法在多孔阳极氧化铝的柱形微孔内制备含钴纳米线有序阵列.分别用扫描电镜(SEM)、X射线衍射仪对多孔阳极氧化铝模板和纳米线阵列的微观形貌和结构进行分析,结果显示阳极氧化铝膜内确有钴生成,且钴纳米线中的晶粒在生长过程中有(100)晶面...     

一种可控纳米柱阵列的研制

在一次阳极氧化法制备多孔氧化铝(anodized aluminum oxide,AAO)的基础上,进行了二次、三次、四次氧化制备AAO,并对多次氧化制备多孔AAO的电流变化曲线和模板表面的形貌特点等进行了比较分析.二次、三次、四次氧化制备的AAO纳米孔孔径依次增大、孔间距减小,而模板表面的纳米孔有序性分布没有明显变化.控制一次氧化AAO模板的除膜时间,～10 min即可得到孔径规则、高度有序的AAO膜.最后,利用所制备的不同孔深和孔径的AAO为模板,通过热纳米压印复制技术制备了长度和直径等性质可控的PMMA纳米柱阵列. 关键词： 纳米柱阵列 聚甲基丙烯酸甲酯 多孔氧化铝模板 多次氧化法     

金属铜纳米孔洞阵列膜制备方法研究

以多孔阳极氧化铝膜(anodic aluminum oxide，AAO)为模板，用真空蒸镀法复制了金属铜的纳米孔洞阵列膜，SEM结果表明，制备得到的金属铜纳米孔洞阵列膜形貌与AAO膜一致.此方法简单易行，能大规模生产，为纳米膜的工业化复制提供了一种新的工艺，为纳米线、纳米管等纳米阵列材料的合成与组装提供了有利的条件. 关键词： AAO模板 真空蒸镀 金属铜纳米孔洞阵列膜 纳米复制     

制备条件对含铜阳极氧化铝复合薄膜偏振特性的影响

利用多孔阳极氧化铝(PAA)的纳米列阵结构,将金属铜电镀到氧化铝的孔中,得到含有金属铜纳米列阵阳极氧化铝(Cu/PAA)膜。实验中发现,Cu/PAA膜的偏振特性与电镀条件有关。在一定的范围内,随着电镀时间和电流密度的增加,消光比增大。电镀溶液的温度也是影响Cu/PAA膜消光比的一个很重要的因素,在电镀溶液温度相对较高的情况下,电流密度相对较小时也可以获得相对较高的消光比。通过优化电镀条件可获得高效率的Cu/PAA膜微偏振器。这种电化学方法制备的微偏振器,制备工艺简单,尺寸可控,便于实现产业化,有广泛的应用前景。     

铜钴合金纳米有序阵列的光学特性

用电化学法制备了高度有序的多孔阳极氧化铝模板, 选用CoSO4和CuSO4的混合溶液为电解液,用交流电化学沉积法在多孔阳极氧化铝的柱形微孔内制备铜钴合金纳米线有序阵列.分别用扫描电镜(SEM),X 射线衍射仪(XRD)对多孔氧化铝模板和纳米线阵列的微观形貌和结构进行分析.结果显示,制备的合金纳米线表面光滑、均匀,纳米线中的晶粒在长过程中有(111) 晶面的择优取向.用UV3101分光光度计测试了铜钴合金多孔铝复合结构的透射光谱及偏振光谱表明,合金纳米复合结构在可见及近红外波段具有良好的透射比和消光比;铜钴合金纳米复合结构的确能够改善单一金属的特性,比如在近红外光区,其消光比(30 dB)优于铜纳米复合结构(17 dB).     

多孔氧化铝薄膜的制备和光学特性研究

采用阳极氧化法制备了二维有序纳米孔氧化铝膜.研究了工艺参数对多孔薄膜有序性、孔径、膜厚度等的影响，测量了多孔氧化铝有序膜的光透过、光吸收和光发射等光学特性.结果表明，在波长360 nm附近多孔氧化铝有序膜的光透过谱线和光吸收谱线发生突变，波长大于360 nm时，光透过增强；波长小于360 nm时，光吸收增强.多孔氧化铝有序膜的光致发光强度和峰位与激发光波长有关，光致发光谱范围在340~600 nm.     

二次阳极氧化方法制备有序多孔氧化铝膜

通过二次阳极氧化方法制备多孔氧化铝膜与一次阳极氧化方法制备多孔氧化铝膜孔排布规律性的对比 ,结果发现 ,二次阳极氧化方法制取的多孔氧化铝膜孔排布规律性明显好于一次阳极氧化法制取的多孔膜 .在几个微米范围内 ,孔呈理想的六角排布 .去除一次阳极氧化膜后 ,二次阳极氧化得以在更良好的表面进行 ,制取的氧化铝膜孔规律性和有序度更高 .有序区域的尺寸与晶粒内的亚晶大小有一定关系     

模板技术制备-维纳米纤维及其阵列

以阳极多孔氧化铝膜为模板，制备了一系列一维结构材料及其阵列体系，材料的结构和阵列方式可调．主要包括两方面内容：通过功能单体的自由基聚合，制备了核壳结构的双重凝胶纳米纤维PDMA／PNH4AA及其阵列，控制氧化铝膜表面的润湿性，双重凝胶纳米纤维的核壳结构可以发生相反转，通过银离子与PNH4AA相的选择性复合，制备了柔性银纳米纤维或管；结合嵌段共聚物的自组装和无机物的溶胶／凝胶过程，制备了一维有序介孔二氧化硅及其阵列体系，改变嵌段共聚物的浓度，可以控制二氧化硅的介观结构．此材料易于进行异质复合，因而便于制备功能性一维复合材料及其阵列体系．     

Fabrication of metal nanodot arrays using a porous alumina membrane as a template

Thin nanodotstructured metal films and heterostructured nanodot arrays (metal nanodot arrays/Si) with a high density and uniform distribution for various kinds of metals (Au, Al, Ag, Pb, Cu, Sn, and Zn) were fabricated by thermal vacuum evaporation using an anodic porous alumina membrane as a template. However, for such metals as Sn, Zn, and Pb with relatively lower melting point as compared with Al it was found that heterostructured nanodot arrays were not formed by a single stage of evaporation. For these metals, we developed a new method termed “two step evaporation method”. The size and the arrays of dots were depended on the pore structure in the anodic porous alumina template. The technique demonstrated in this report is simple and suitable for the preparation of nanodot arrays in the large area for materials which could be vacuum evaporated.     

Template synthesis of single-crystal Cu nanowire arrays by electrodeposition

Cu nanowire arrays have been synthesized using potentiostatic electrodeposition within the confined nanochannels of a porous anodic alumina membrane. The Cu nanowire arrays and the individual nanowires have been characterized using SEM, TEM, SAED, HREM and XRD. Investigation results reveal that the Cu nanowire arrays having high wire packing densities are highly ordered over large areas. The individual Cu nanowires (diameter ∼60 nm) were single-crystal and found to be dense and continuous with uniform diameters throughout their entire length. An optimum ECD condition (at lower overpotentials) for the synthesis of single-crystal Cu nanowires was also discussed. Received: 19 April 2001 / Accepted: 28 April 2001 / Published online: 20 June 2001     

Pluronic P123 assisted synthesis of hollow InSn/In2O3 hybrid nanoparticles by solution dispersion

A detailed analysis of the optimum regimes of pulsed current metal electrodeposition into pores of porous anodic alumina PAA is presented. A simple model based on cathodic and anodic current transients is developed. The model is based on a simplified equivalent circuit consisting of two capacities related to the barrier and porous parts of porous anodic alumina. Nanowires of Cd, Zn, In, Ni, Co, Ag, and Cu were embedded into PAA by pulsed electrodeposition using an asymmetric rectangular ac signal. Deposited metal nanowires were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), optical spectroscopy, Auger electron spectroscopy (AES), and X-ray diffractometry (XRD).     

Fabrication of well-aligned CdS nanotubes by CVD-template method

Well-aligned CdS nanotubes have been synthesized within the nanochannels of the porous anodic alumina (PAA) membranes by pyrolyzing cadmium bis(diethyldithiocarbamate) [Cd(S₂CNEt₂)₂] at 400 °C. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the CdS nanotubes are highly ordered with uniform diameter in range of 80-150 nm and the length up to tens of microns. X-ray diffraction (XRD), Raman spectrum, energy-dispersive spectroscopy (EDS) and selected-area electron diffraction (SAED) demonstrate that the nanotubes are composed of pure hexagonal phase polycrystalline CdS. The synthetic route can, in principle, be extended to fabricate other nanotubes of a wide range of semiconductors.     

Investigation of the super-long alumina nanowire array synthesized with a novel method

Alumina nanowire array standing on porous anodic alumina (PAA) membrane has been directly and efficiently synthesized in oxalic acid solution by one-step electrochemical anodic oxidation with changing anodic voltages. The morphology of the nanowires on PAA was observed by scanning electron microscopy (SEM). The different patterns on the surface of the sample were synthesized due to the reaction time. The fine structure of the patterns has shown that the pattern is composed of the alumina nanowire array and the morphologies of the patterns can mainly be attributed to the differences in the length of the alumina nanowires. The method of selected area electron diffraction (SAED) for transmission electron microscopy (TEM) has shown that these nanowires are amorphous. An etching model was given to explain the formation mechanism of the amorphous alumina nanowires.     

Controllable synthesis of highly ordered Ag nanorod arrays by chemical deposition method

Highly ordered Ag nanorod arrays were successfully fabricated using a simple chemical deposition method with the assistance of porous alumina membrane (PAM) template. The products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Ag⁺ ions in the PAM nanochannels were reduced by acetaldehyde reagent and resulting in the formation of rod array structures. It is found that the diameter of the Ag nanorods is determined by the PAM template, and the length of the Ag nanorods is depended on the reaction temperature. The growth mechanism of the Ag nanorod arrays is investigated in the study.     

基于包络线法的多孔阳极氧化铝薄膜光学常数的计算

采用二步阳极氧化法在草酸溶液中制备了多孔阳极氧化铝(PAA)薄膜。借助于扫描电子显微镜(SEM)分析了多孔阳极氧化铝薄膜的微观形貌。结果发现,在其表面孔径为30~40nm的六边形孔洞分布均匀,且垂直于表面平行生长。依据PAA透射光谱的实验数据,采用极值包络线算法计算出了PAA薄膜的复折射率以及光学能隙等光学常数。通过分析吸收系数与入射光子能量之间的关系发现,PAA薄膜具有直接带隙半导体的电子结构特征,而且由理论计算得到的PAA的带隙能与其光致发光谱的峰位能是一致的。