无机铝盐制备有序介孔氧化铝及其表征

以硝酸铝为原料、非离子型表面活性剂聚乙二醇为模板剂、碳酸铵为沉淀剂,采用沉淀法合成有序介孔氧化铝;通过热分析方法、X射线衍射、氮吸附平衡等温线和透射电镜等测试技术对合成样品进行了结构表征。结果表明,合成的有序介孔氧化铝比表面积为296m²/g、孔径分布窄（2.8～4.0nm）、孔容在0.45cm³/g以上,且孔道呈蠕虫状并具有一定的有序性。     

氧化铝多孔陶瓷凝胶注模成型研究

以TH-903为分散剂,刚玉粉体为基体材料,以碳粉为造孔剂,采用凝胶注模成型方法制备了多孔氧化铝陶瓷.研究了分散剂、球磨时间和固相含量对浆料粘度的影响以及造孔剂含量对多孔陶瓷性能的影响.结果表明:加入质量分数为2.5%的分散剂可制得低粘度、高固相含量的陶瓷浆料.成型后的坯体经1360℃烧结1h,可获得孔径分布均匀、高显气孔率及强度较高的产品.     

Extraction and characterization of alumina nanopowders from aluminum dross by acid dissolution process

A significant amount of aluminum dross is available as a waste in foundry industries in Bangladesh. In this study, alumina was extracted from aluminum dross collected from two foundry industries situated in Dhamrai and Manikgang, near the capital city, Dhaka. Aluminum dross samples were found to approximately contain 75wt% Al₂O₃ and 12wt% SiO₂. An acid dissolution process was used to recover the alumina value from the dross. The effects of various parameters, e.g., temperature, acid concentration, and leaching time, on the extraction of alumina were studied to optimize the dissolution process. First, Al(OH)₃ was produced in the form of a gel. Calcination of the Al(OH)₃ gel at 1000℃, 1200℃, and 1400℃ for 2 h produced θ-Al₂O₃, (α+θ)-Al₂O₃, and α-alumina powder, respectively. Thermal characterization of the Al(OH)₃ gel was performed by thermogravimetric/differential thermal analysis (TG/DTA) and differential scanning calorimetry (DSC). The phases and crystallite size of the alumina were determined by X-ray diffraction analysis. The dimensions of the alumina were found to be on the nano level. The chemical compositions of the aluminum dross and alumina were determined by X-ray fluorescence (XRF) spectroscopy. The microstructure and morphology of the alumina were studied with scanning electron microscopy. The purity of the alumina extracted in this study was found to be 99.0%. Thus, it is expected that the obtained alumina powders can be potentially utilized as biomaterials.     

多孔氧化铝纳米材料对姜黄素的吸附性能和发光性质影响的研究

通过阳极氧化法制备的孔径约20～150nm的多孔氧化铝纳米材料，表现出较强的吸附性能，主要利用物理吸附在纳米孔中填入有机荧光小分子姜黄素，与溶液中的发光现象相比，观察到了姜黄素的光谱蓝移现象，表明纳米孔对有机分子发光有较大的影响。     

Synthesis of ordered Si nanowire arrays in porous anodic aluminum oxide templates

Highly ordered polycrystalline Si nanowire arrays were synthesized in porous anodic aluminum oxide (AAO) templates by the chemical vapor deposition (CVD) method. The morphological structure, the crystal character of Si nanowire arrays and the individual nanowire were analyzed by the transmission electron microscopy (TEM), scanning electron microscopy (SEM), atom force microscopy (AFM) and the X-ray diffraction spectrum (XRD), respectively. It is shown that most fabricated silicon nanowires (SiNWs) tend to be assembled parallelly in bundles and constructed with highly orientated arrays. This method provides a simple and low cost fabricating craftwork and the diameters and lengths of SiNWs can be controlled, the large area Si nanowire arrays can be achieved easily under such a way. The curling and twisting SiNWs are fewer than those by other synthesis methods.     

Spectral behavior of 8-hydroxyquinoline aluminum in nanometer-sized holes of porous alumina

The porous alumina have been prepared by anodization and an organic molecule 8-hydroxyquinoline aluminum (Alq₃) has been impregnated in the pores. The morphology measured through atomic force microscopy shows that the size of the pores is about 10 nm. A blue-shift photoluminescence of Alq₃ in nanometer-sized hole is close to that of the monomers. The measured spectral characteristics demonstrate the limitation of the porous alumina to the emission of Alq₃.     

多孔氧化铝成膜条件的研究及其应用

为了研究多孔氧化铝的成膜条件,以0.3 mol/L草酸为电解液,通过两次阳极氧化制备出多孔氧化铝模板.通过扫描电镜(SEM),X射线衍射(XRD)对模板形貌进行观察,研究了多孔阳极氧化铝的制备和成膜条件.以制备的氧化铝膜为阴极,铂电极为阳极,硝酸锌和六亚甲基四胺为电解溶液,采用溶液沉积制备点阵列氧化锌晶体并讨论发光性能...     

大孔径多孔氧化铝膜的制备

本文使用磷酸和草酸的混合溶液为电解液,在90V电压下,控制电解液温度在5～10℃制备了平均孔径高达200nm,开孔密度为1.7×109pores/cm2的多孔阳极氧化铝（AAO）膜。与使用单一酸为电解质相比,使用混合酸制备大孔径氧化铝膜所需的电压较低,电流密度较小,对氧化温度的要求也不苛刻。     

Fabrication of porous alumina templates with a large-scale tunable interpore distance in a H_2C_2O_4-C_2H_5OH-H_2O solution

Highly ordered porous alumina templates with a large-scale tunable interpore distance (100―445 nm) have been successfully fabricated under an electric field of 40―180 V by modifying oxalic acid solution with adequate alcohol. The results under our experimental conditions show that the phenomena of burning and breakdown during the high-field anodization process can be avoided by adding a proper amount of alcohol to the oxalic acid solution. An excellent linear relationship between interpore distance and anodization voltage is obtained under 40―170 V, and the maximum anodization voltage that could be used to avoid burning and breakdown is 180 V.     

草酸中多孔阳极氧化铝膜生长动力学和形态结构研究

为分析多孔阳极氧化铝膜形态参数和氧化条件的关系,在恒流条件下对0.3 mol.L-1草酸电解中形成多孔膜的生长动力学进行了研究.采用扫描电子显微镜和氧化膜质量测定方法检验了电流密度、温度和氧化时间对氧化膜生长动力学和氧化膜形态的影响.通过电压-时间曲线研究了氧化膜的电化学特征,并采用一元线性回归模型预测了氧化膜的生长速率.实验结果表明氧化膜的生长速率随电流密度的升高而升高,随温度的升高而下降.氧化膜质量的增长速率也随着电流密度的升高而增大.     

草酸中多孔阳极氧化铝膜生长动力学和形态结构研究

为分析多孔阳极氧化铝膜形态参数和氧化条件的关系,在恒流条件下对0.3 mol·L-1草酸电解中形成多孔膜的生长动力学进行了研究.采用扫描电子显微镜和氧化膜质量测定方法检验了电流密度、温度和氧化时间对氧化膜生长动力学和氧化膜形态的影响.通过电压-时间曲线研究了氧化膜的电化学特征,并采用一元线性回归模型预测了氧化膜的生长速率.实验结果表明氧化膜的生长速率随电流密度的升高而升高,随温度的升高而下降.氧化膜质量的增长速率也随着电流密度的升高而增大.     

多孔氧化铝的整流特性研究

在温度0℃下,采用阳极氧化法分别在15％wt的硫酸水溶液、0．3mol／L的草酸水溶液和0．3mol／L的磷酸水溶液中制备了多孔氧化铝薄膜．电压分别为18V、40V和90V,氧化时间是1h．利用扫描电子显微镜（SEM）对多孔氧化铝薄膜的结构形貌进行了表征,测量了Al／Al2O3界面的电流电压（I-U）特性曲线,并对多孔铝整流特性的机理进行了分析,很好地解释了交流电沉积的原因．随着科技的发展,人类将通过利用多孔铝的整流特性制备出各种各样的性能优良的材料和器件．     

含铬铝泥制备超纯Al2O3粉体

为解决无钙焙烧生产铬产品时产生的含铬铝泥的污染问题,本文在去除铝泥中铬成分后,采用聚乙二醇（PEG）600和六偏磷酸钠（SHMP）为分散剂制备了高纯Al2O3粉体。结果表明,Al2O3,粉体中未检出Cr、Fe等成分,为高纯粉体。加入0．5％PEG600为分散剂时粉体的平均粒径较小,样品颗粒的团聚现象明显减少,颗粒间层叠...     

利用电化学法制备Pt纳米线

利用阳极氧化铝（AAO）作为模板,制备出高定向的Pt纳米线。Pt纳米线的形貌由环境扫描电镜证实,并通过x-射线能谱（EDX）、X-射线粉末衍射谱（XRD）测试手段进行了表征。     

磁性氧化铁纳米线的制备与表征

通过溶胶-凝胶法在氧化铝模板（AAO）中制备出了磁性Fe_2O_3纳米线阵列,然后去除AAO模板得到磁性Fe_2O_3纳米线。用SEM,TEM,FTIR,EDX,VSM对磁性纳米线的形貌、微结构和磁性能进行表征。SEM和TEM结果显示磁性纳米线的直径约为50～80nm,长度在8～10μm,长径比为120～180;FTIR和EDX结果表明制备的产物是磁性Fe_2O_3纳米线;VSM结果表明磁性氧化铁纳米线阵列存在明显的磁各向异性。此外,采用Zeta电位仪对磁性Fe_2O_3纳米线表面的电性进行了研究,结果表明纳米线表面带正电荷,有利于和动物细胞相结合。     

Synthesis of carbon nanotube arrays using ethanol in porous anodic aluminum oxide template

Carbon nanotube (CNT) arrays confined by porous anodic aluminum oxide (AAO) template were synthesized using ethanol as reactant carbon source at low pressure. Images by scanning electron microscope (SEM) and low magnification transmission electron microscopy (TEM) show that these CNTs have highly uniform outer diameter and length, absolutely controlled by the diameter and depth of nano-channel arrays of the AAO. High resolution transmission electron microscopy (HRTEM) imaging indicates that the graphitization of the CNT walls is better than the results reported on this kind of template-based CNT arrays, although it is not so good as that of multiwalled carbon nanotubes (MWCNTs) synthesized by catalysis. CNTs synthesized using acetylene as reactant gas show much less graphitization than those prepared using ethanol by comparing the results of HRTEM and Raman spectroscopy. The etchingeffects of decomposed OH radicals on the amorphous carbon and the roughness of AAO nano-channel arrays on the CNTs growth were employed to explain the graphitization and growth of the CNTs.     

多孔氧化铝膜的制备及其表征

在硫酸、磷酸及草酸溶液中 ,通过阳极氧化铝箔制备出了多孔氧化铝模板 ,用阶梯降压法将氧化铝层与铝基底分离 .透射电镜结果表明 :这种膜的孔间距 ,孔径以及晶胞尺寸均随所加氧化电压的增加而增加 .通过 FT- IR谱发现 ,在阳极氧化过程中 ,电解液阴离子也参与了多孔膜的形成 .XRD谱证明形成了无定形氧化铝     

制备多孔氧化铝的影响因素研究

在草酸电解液中,用阳极氧化法制备了多孔氧化铝.用扫描电子显微镜对多孔氧化铝的形貌进行了观察表征,研究了制备多孔氧化铝的若干影响因素.实验结果表明：退火预处理、合适的氧化时间和氧化电压能有效保障多孔氧化铝的质量,制备高质量多孔氧化铝的温度与草酸浓度和电压等参数存在一定的依存关系.     

Effect of Fe metal on the growth of silicon oxide nanowires

Silicon oxide (SiO_x) nanowires are generally grown on Si substrate under the catalysis of Au in N₂ atmosphere at elevated temperatures. Because the price of Au metal is quite high, Fe metal is then used to replace a part of Au for catalyzing the growth of SiO_x nanowires. The results show that the Fe film can be used as the diffusion barrier of Au. SiO_x nanowires are grown on Au/Fe/Si substrate at 1030℃. Under the catalysis of Fe/Au, the efficiency for the growth of SiO_x nanowires is promoted.     

新型氧化铝矿浆烧成炉内热过程的数值模拟

在了解氧化铝矿浆干燥、烧成工艺及设备的基础上,针对中国铝业股份有限公司中州分公司开发的一种新的氧化铝矿浆干燥和烧成炉,建立了矿浆干燥、烧成炉内气固两相流的流动传热以及烧成过程的数学模型,就干燥、烧成炉运行参数及各几何参数进行优化计算,得出了炉内气固两相流动的速度场、温度场、压力场以及颗粒干燥和烧成反应时间,并分析讨论了喷口位置、喷口速度、颗粒雾化粒径等参数对氧化铝矿浆干燥、烧成工艺的影响.