两步阳极氧化法制备多孔阳极氧化铝膜

直流恒压下,在酸性溶液中对铝实施两步阳极氧化制备了多孔氧化铝膜。采用扫描电镜(SEM)、原子力显微镜(AFM)对制备的多孔氧化铝膜进行形貌分析,孔径在纳米级且孔分布具有高度均匀性。采用SEM对试样进行观察,分析了工艺对多孔氧化铝膜形貌的影响。利用阳极氧化初期电流密度的变化并结合阳极氧化过程中的试样的SEM照片,分析了多孔氧化铝膜的形成机理。     

Room temperature synthesis of samarium oxide nanotubes using cost-effective electroless deposition method

Nanotubes consisting of samarium oxide (SmNT) were fabricated by electroless deposition using ion track-etched polycarbonate templates. To achieve nanotubes with thin walls and small surface roughness, the tubes were generated by a procedure containing several steps under aqueous conditions. The approach reported below will process open-ended nanotubes with well-defined outer diameter and wall thickness.     

草酸溶液中制备大孔间距的通孔PAA模板

为了制备规则有序、大孔间距的多孔阳极氧化铝(PAA)模板,通过在传统的草酸溶液中添加乙醇以及阶梯升压的方法,使草酸溶液的耐压从原来的40V左右提高至150V,制备了大孔径(约200nm)、大孔间距(约350nm)的有序PAA模板。详细研究了这种高电压氧化得到的具有较厚阻挡层PAA模板的通孔工艺,实验结果表明,在5%(质量分数)磷酸水溶液中30℃下浸泡180min,可以得到有序的PAA通孔模板,首次计算了阻挡层的减薄速率为约1.26nm/min。     

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.     

Fabrication of Ag and Cu nanowires by a solid-state ionic method and investigation of their third-order nonlinear optical properties

Ag and Cu nanowires were separately fabricated in a direct current electric field using a solid-state ionic method, and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Their optical nonlinearities induced by 8 ns laser pulses from a frequency-doubled, Nd:YAG laser at 532 nm, were investigated using the Z-scan technique. Experimental results indicate the metal nanowires have obvious positive refractive nonlinearities and reverse saturated absorption behaviors. The self-focusing behaviors of Ag and Cu nanowires can be attributed to Kerr-induced self-focusing of laser radiation, the nonlinear refractive indexes of Ag and Cu nanowires are n₂ = 1.7 × 10^− 11 esu and n₂ = 2.4 × 10^− 11 esu respectively, and the two-photon process of Ag and the one-photon process of Cu are responsible for the difference between Ag and Cu nanowires suspended in de-ionized water in nanosecond nonlinear absorptions.     

铜纳米线阵列的模板组装

采用电解法溶解多孔阳极氧化铝(PAA)模板的阻挡层,用直流电沉积的方法在模板中组装了铜纳米线阵列.分别用扫描电镜和X射线衍射表征铜纳米线阵列的形貌和晶体结构,用电化学法表征了铜纳米线阵列的电催化性能.结果表明,PAA去阻挡层后,伏安图上出现一个阳极氧化峰.恒电位沉积的铜纳米线直径为22nm,沿(111)晶面择优取向.铜纳米线阵列电极能催化亚硝酸根的还原,其催化电流比本体铜电极上大2倍,峰电位正移80mV.纳米铜阵列电极可用于亚硝酸盐的电化学检测.     

TEM-based metrology for HfO2 layers and nanotubes formed in anodic aluminum oxide nanopore structures

Nanotubes are fabricated by atomic layer deposition (ALD) into nanopore arrays created by anodic aluminum oxide (AAO). A transmission electron microscopy (TEM) methodology is developed and applied to quantify the ALD conformality in the nanopores (thickness as a function of depth), and the results are compared to existing models for ALD conformality. ALD HfO2 nanotubes formed in AAO templates are released by dissolution of the Al2O3, transferred to a grid, and imaged by TEM. An algorithm is devised to automate the quantification of nanotube wall thickness as a function of position along the central axis of the nanotube, by using a cylindrical model for the nanotube. Diffusion-limited depletion occurs in the lower portion of the nanotubes and is characterized by a linear slope of decreasing thickness. Experimentally recorded slopes match well with two simple models of ALD within nanopores presented in the literature. The TEM analysis technique provides a method for the rapid analysis of such nanostructures in general, and is also a means to efficiently quantify ALD profiles in nanostructures for a variety of nanodevice applications.     

交流电化学沉积铜纳米线阵列及其机理探讨

利用二次阳极氧化的方法制备孔高度有序的阳极氧化铝(AAO)为模板,采用交流电化学沉积方法,在AAO模板孔道内制备Cu纳米线。采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线衍射仪(XRD)对Cu纳米线的形貌、晶体结构进行研究。结果表明:模板的孔径均匀,孔道平直。Cu纳米线均匀分布在AAO模板纳米孔隙中,直径均一,并沿Cu(Ⅲ)晶面择优生长;AAO模板孔道生长铜纳米线不光滑,成凹凸状,并对此沉积机理进行探讨。     

模板浸润法制备可生物降解聚合物纳米管和纳米线

以孔径为200nm的阳极氧化铝（AAO）为模板，用简单的物理方法制备了生物可降解聚合物聚己内酯（PCL）的纳米管、线及其阵列结构。SEM和TEM测试结果表明：熔融法在120℃和140℃都能制得整齐的纳米管阵列结构，管径均匀，约300nm。在溶液法中，5％浓度的溶液制得了杂乱的纳米管，而10％浓度的溶液制得的是纳米线阵列，直径在200nm左右。     

Fabrication of single-crystalline gallium nitride nanowires by using alginate as template

Hexagonal gallium nitride nanowires were synthesized successfully by solvothermal method with alginate as template. The microstructure, morphologies and compositions of the as-prepared product were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray (EDX). Results suggested that the rod-like nanowires were hexagonal single-crystalline GaN growing along [001] direction. The photoluminescence spectra (PL) of the GaN revealed that the as-synthesized sample possesses excellent optical properties.     

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。     

磁性金属纳米结构的制备与表征

采用电化学沉积方法成功地制备了高度有序的镍纳米管/线阵列结构,并用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线衍射(XRD)对产物的微观形貌和化学结构进行了表征和分析.测试结果显示,镍纳米结构阵列规整,镍纳米管壁具有多晶体结构;X射线衍射图谱表明,镍纳米管壁具有较高的结晶度.研究了沉积时间对镍纳米结构的影响.     

A combined template and closed space sublimation approach to the synthesis of single-crystalline CdS nanowires and their optical properties

High-quality single-crystalline CdS nanowires about 40 nm in diameter have been successfully synthesized without any catalyst at ambient pressure by combining the closed space sublimation (CSS) technique with porous anodic alumina membrane (AAM) template method. Extensive characterizations of the nanowires have been carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Raman spectroscopy and UV-Visible absorption spectroscopy. A band gap of 2.38 eV is determined from the UV-Vis absorption spectrum obtained from the nanowire sample. Our facile technique may in principle also be used for synthesizing other one-dimensional (1D) materials with high vapor pressure and axial nanowire heterostructures.     

Synthesis and characterisation of selenium nanowires using template synthesis

Selenium (Se) nanowires were grown in the pores of anodic alumina membrane as template. Facile electrodeposition technique was used for the synthesis of Se nanowires. Scanning electron microscopy was used for the morphological study of the nanowires. X-ray diffraction and Energy dispersive X-ray fluorescence were utilised for the structural characterisation. The optical properties of Se nanowires were investigated using optical absorption spectroscopy.     

多孔氧化铝模板的纳米力学性能测试与分析

为了掌握多孔氧化铝模板的纳米力学性能,采用二次氧化法制备孔径在30～40nm之间且高度有序的纳米阵列氧化铝模板,并使用扫描电子显微镜(SEM)对其形貌进行表征;在原位纳米力学测试系统上进行微压痕实验,对样品表面力学性能(纳米硬度、模量)进行测试;利用原子力成像功能对实验区域扫描成像,在纳米尺度下观察和分析样品形貌.结果表明,AAO模板在同一深度处对应的硬度、模量值明显高于相应的基体材料铝,膜基体系的抗载能力明显提高;在压入深度为70～240nm时,AAO膜板的硬度和模量值分别为5.8GPa和106GPa,但从深度250nm时开始出现减小趋势;单晶铝与压针的接触为理想刚塑性接触,AAO模板与压针的接触为弹塑性接触.     

多孔氧化铝模板结合sol-gel旋转涂敷法制备PZT纳米管

利用溶胶-凝胶旋转涂敷法在通孔的多孔阳极氧化铝(PAA)模板中制备了锆钛酸铅(PZT)纳米管,研究了溶胶浓度对样品形貌的影响。利用SEM和TEM观察了纳米管阵列和单根纳米管的形貌,采用XRD和EDS图谱分析了纳米管的相结构和化学元素组成。结果表明合成的PZT纳米管结晶良好,具有钙钛矿结构(属于四方晶系);纳米管具有较高的韧性但表面较粗糙,直径和管壁厚度分别约为75和7nm,直径与原始PAA模板的孔径相吻合。在一定范围内调节PZT溶胶的浓度(0.1～0.4mol/L),均能在PAA模板的孔洞中形成PZT多晶纳米管,且组成PZT纳米管的晶粒随着溶胶浓度的增加而变大。     

Structural,thermal and dielectric studies of polypyrrole nanotubes synthesized by reactive self degrade template method

In this work we investigate the structural, thermal and dielectric properties of polypyrrole nanotubes synthesized by in situ chemical oxidative polymerization method. Cetyl trimethylammonium bromide (CTAB) modified Methyl Orange (MO)-FeCl₃ reactive self degrade template is used to support the growth of PPy nanotubes. The diameter of the tubes decreased with increase in CTAB concentration and found to be 140–52 nm. The synthesized polypyrrole nanotubes are investigated by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), FTIR, UV–vis, conductivity measurements, TGA and impedance analysis. TGA analysis shows decrease in decomposition rate with decrease in tube diameter. The response of the charge carriers to the ac field is also carried out in the frequency range of 42 Hz–5 MHz. The shifting of peak towards higher frequency in imaginary modulus formalism with decrease in CTAB concentration suggests faster relaxation.     

Fabrication and magnetic properties of Co-Ni-P rod-shaped hollow structures based on Bacillus template

A new type of Co-Ni-P rod-shaped hollow structures was prepared by electroless deposition based on Bacillus template. The metal plating layer was deposited on the surface of Bacillus, which is a kind of rod-shaped bacteria. The composition, microstructure, phase structures and magnetic properties of the hollow structures were studied. The results clearly demonstrated that the Bacillus were coated by Co-Ni-P metal plating layer and the thickness of the metal layer was around 150-200 nm. The average contents of Co, Ni, and P element of the metal layer were about 18.73 wt.%, 74.43 wt.% and 3.04 wt.%, respectively. The values of saturation magnetization (Ms), remnants magnetization (Mr) and coercivity (Hc) of the hollow structures were about 92.5 emu/g, 29.7 emu/g, and 768.7 Oe, respectively.