共查询到19条相似文献,搜索用时 62 毫秒
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简要介绍了纳米氧化铝的特性,综述了制备纳米氧化铝的各种方法及其特点,指出我国纳米氧化铝工业化存在的问题,并对该产业前案做出展望。 相似文献
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提出了以磷酸/草酸混合溶液为电解液制备高度有序锥形多孔阳极氧化铝(PAA)模板的方法。首先采用二次氧化的方法,得到了孔洞排列高度有序且孔间距为495nm的PAA模板。在此基础上,采用阳极氧化过程和扩孔过程交替进行的方法,制备了不同长径比的有序锥形PAA模板。实验结果显示:锥形PAA模板的长径比与总氧化时间线性相关,可达到100以上;还说明了分段氧化时间和分段扩孔时间与锥形孔道形貌之间的关系。这种特殊结构的PAA模板可以大大拓展其在合成金属或半导体纳米线、光电材料以及高分子材料方面的应用范围。 相似文献
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纳米氧化铝作为一种重要的纳米材料,在陶瓷材料、催化剂载体等领域有着广泛的应用.首先介绍了纳米氧化铝的主要形态,然后分别对纳米氧化铝的3种主要的制备方法(固相法、气相法、液相法)进行说明,并着重论述了目前应用比较广泛的液相法和介孔纳米氧化铝的制备.最后,提出了一些在纳米氧化铝的制备研究中有待解决的问题. 相似文献
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Nanoporous alumina which was produced by a conventional direct current anodization [DCA] process at low temperatures has received much attention in various applications such as nanomaterial synthesis, sensors, and photonics. In this article, we employed a newly developed hybrid pulse anodization [HPA] method to fabricate the nanoporous alumina on a flat and curved surface of an aluminum [Al] foil at room temperature [RT]. We fabricate the nanopores to grow on a hemisphere curved surface and characterize their behavior along the normal vectors of the hemisphere curve. In a conventional DCA approach, the structures of branched nanopores were grown on a photolithography-and-etched low-curvature curved surface with large interpore distances. However, a high-curvature hemisphere curved surface can be obtained by the HPA technique. Such a curved surface by HPA is intrinsically induced by the high-resistivity impurities in the aluminum foil and leads to branching and bending of nanopore growth via the electric field mechanism rather than the interpore distance in conventional approaches. It is noted that by the HPA technique, the Joule heat during the RT process has been significantly suppressed globally on the material, and nanopores have been grown along the normal vectors of a hemisphere curve. The curvature is much larger than that in other literatures due to different fabrication methods. In theory, the number of nanopores on the hemisphere surface is two times of the conventional flat plane, which is potentially useful for photocatalyst or other applications.PACS: 81.05.Rm; 81.07.-b; 82.45.Cc. 相似文献
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多孔阳极氧化铝膜具有高度有序的独特的纳米级孔结构,引起了越来越多的关注和重视,可将其用于研制新型超精密分离膜或作为模板开发各种新型功能材料。本文总结了阳极氧化铝膜的制各方法及形成机理,并概述了其在气体、液体、生物化工的分离应用,对其在分离方面的发展趋势进行了分析及展望。 相似文献
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MM Rahman E Garcia-Caurel A Santos LF Marsal J Pallarès J Ferré-Borrull 《Nanoscale research letters》2012,7(1):474
ABSTRACT: A detailed study of the pore-widening rate of nanoporous anodic alumina layers as a function of the anodization voltage was carried out. The study focuses on samples produced under the same electrolyte and concentration but different anodization voltages within the self-ordering regime. By means of ellipsometry-based optical characterization, it is shown that in the pore-widening process, the porosity increases at a faster rate for lower anodization voltages. This opens the possibility of obtaining three-dimensional nanostructured nanoporous anodic alumina with controlled thickness and refractive index of each layer, and with a refractive index difference of up to 0.24 between layers, for samples produced with oxalic acid electrolytes. 相似文献
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Laura P Hernández-Eguía Josep Ferré-Borrull Gerard Macias Josep Pallarès Lluís F Marsal 《Nanoscale research letters》2014,9(1):414
The effect in the Fabry-Pérot optical interferences of nanoporous anodic alumina films coated with gold is studied as a function of the porosity and of the gold thickness by means of reflectance spectroscopy. Samples with porosities between 14 and 70% and gold thicknesses (10 and 20 nm) were considered. The sputtering of gold on the nanoporous anodic alumina (NAA) films results in an increase of the fringe intensity of the oscillations in the spectra resulting from Fabry-Pérot interferences in the porous layer, with a reduction in the maximum reflectance in the UV-visible region. For the thicker gold layer, sharp valleys appear in the near-infrared (IR) range that can be useful for accurate spectral shift measurements in optical biosensing. A theoretical model for the optical behavior has also been proposed. The model shows a very good agreement with the experimental measurements, what makes it useful for design and optimization of devices based on this material. This material capability is enormous for using it as an accurate and sensitive optical sensor, since gold owns a well-known surface chemistry with certain molecules, most of them biomolecules. 相似文献
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A study of reflective interference spectroscopy [RIfS] properties of nanoporous anodic aluminium oxide [AAO] with the aim
to develop a reliable substrate for label-free optical biosensing is presented. The influence of structural parameters of
AAO including pore diameters, inter-pore distance, pore length, and surface modification by deposition of Au, Ag, Cr, Pt,
Ni, and TiO2 on the RIfS signal (Fabry-Perot fringe) was explored. AAO with controlled pore dimensions was prepared by electrochemical
anodization of aluminium using 0.3 M oxalic acid at different voltages (30 to 70 V) and anodization times (10 to 60 min).
Results show the strong influence of pore structures and surface modifications on the interference signal and indicate the
importance of optimisation of AAO pore structures for RIfS sensing. The pore length/pore diameter aspect ratio of AAO was
identified as a suitable parameter to tune interferometric properties of AAO. Finally, the application of AAO with optimised
pore structures for sensing of a surface binding reaction of alkanethiols (mercaptoundecanoic acid) on gold surface is demonstrated. 相似文献
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草酸中纳米孔阵列阳极氧化铝膜的一步法制备及其形貌表征 总被引:1,自引:2,他引:1
报道了用一步阳极氧化法在经过预处理的高纯铝片上制备具有纳米孔阵列结构的阳极氧化铝膜(AAM)的技术,并用扫描电子显微镜(SEM)和原子力显微镜(AFM)对样品形貌进行了表征。结果表明,高纯铝片在0~20℃、0.1~0.5 mol/L的草酸溶液中用30~60 V的直流电一步阳极氧化,再经过去铝和除阻挡层的过程,可制得纳米孔阵列阳极氧化铝膜。制得的阳极氧化铝膜中的孔,尺寸都在纳米级别,且大小均匀,相互平行排列成规整阵列,可用作制备纳米线阵列的模板。 相似文献
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Nevin Tasaltin Deniz Sanli Alexandr Joná? Alper Kiraz Can Erkey 《Nanoscale research letters》2011,6(1):487
Superhydrophobic nanoporous anodic aluminum oxide (alumina) surfaces were prepared using treatment with vapor-phase hexamethyldisilazane (HMDS). Nanoporous alumina substrates were first made using a two-step anodization process. Subsequently, a repeated modification procedure was employed for efficient incorporation of the terminal methyl groups of HMDS to the alumina surface. Morphology of the surfaces was characterized by scanning electron microscopy, showing hexagonally ordered circular nanopores with approximately 250 nm in diameter and 300 nm of interpore distances. Fourier transform infrared spectroscopy-attenuated total reflectance analysis showed the presence of chemically bound methyl groups on the HMDS-modified nanoporous alumina surfaces. Wetting properties of these surfaces were characterized by measurements of the water contact angle which was found to reach 153.2 ± 2°. The contact angle values on HMDS-modified nanoporous alumina surfaces were found to be significantly larger than the average water contact angle of 82.9 ± 3° on smooth thin film alumina surfaces that underwent the same HMDS modification steps. The difference between the two cases was explained by the Cassie-Baxter theory of rough surface wetting. 相似文献
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Josep Ferré-Borrull Mohammad Mahbubur Rahman Josep Pallarès Lluís F Marsal 《Nanoscale research letters》2014,9(1):416
The influence of the anodization temperature and of the number of applied voltage cycles on the photonic properties of nanoporous anodic alumina-based distributed-Bragg reflectors obtained by cyclic voltage anodization is analyzed. Furthermore, the possibility of tuning the stop band central wavelength with a pore-widening treatment after anodization and its combined effect with temperature has been studied by means of scanning electron microscopy and spectroscopic transmittance measurements. The spectra for samples measured right after anodization show irregular stop bands, which become better defined with the pore widening process. The results show that with 50 applied voltage cycles, stop bands are obtained and that increasing the number of cycles contributes to enhancing the photonic stop bands (specially for the case of the as-produced samples) but at the expense of increased scattering losses. The anodization temperature is a crucial factor in the tuning of the photonic stop bands, with a linear rate of 42 nm/°C. The pore widening permits further tuning to reach stop bands with central wavelengths as low as 500 nm. Furthermore, the results also show that applying different anodization temperatures does not have a great influence in the pore-widening rate or in the photonic stop band width. 相似文献
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Gerard Macias Josep Ferré-Borrull Josep Pallarès Lluís F Marsal 《Nanoscale research letters》2014,9(1):315
A rugate filter based on nanoporous anodic alumina was fabricated using an innovative sinusoidal current profile with small current variation. The resulting structure consisted of highly parallel pores with modulations of the pore diameter along the pore axis and with no branching. The effect of the period time and the pore widening post-treatment was studied. From reflectance measurements, it was seen that the position of the reflection band can be tuned by adjusting the period time and the width by pore-widening post-treatments. We tested one of the rugate filters by infiltrating the structure with EtOH and water in order to evaluate its sensing capabilities. This method allows the fabrication of complex in-depth modulated nanoporous anodic alumina structures that open up the possibility of new kinds of alumina-based optical sensing devices. 相似文献