共查询到20条相似文献,搜索用时 15 毫秒
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退火对有序孔洞氧化铝膜荧光性能的影响 总被引:1,自引:0,他引:1
用阳极氧化法在草酸溶液或硫酸溶液中制备了有序阵列孔洞的氧化铝膜.研究了在不同温度下、不同气氛中退火对多孔氧化铝膜荧光性能的影响.结果表明,随着退火温度的升高,发光带的强度也随之增强;与此同时,发光带的峰位出现蓝移.当退火温度Ta=500℃时,在草酸中制备的氧化铝膜的发光强度最强;而在硫酸中制备的膜,其发光最强的退火温度为400℃.当 T≤400℃时,氧化铝膜的发光强度基本上与退火气氛无关;当 Ta=500℃时,在草酸中制备的膜在空气中退火后的发光强度高于在真空中退火后的发光强度.在草酸中制备的氧化铝膜的发光带明显比在硫酸中制备的膜强得多.电子自旋共振的实验结果表明,蓝光发光带来自多孔氧化铝膜中的F+心.我们还对多孔氧化铝膜发光特性的机制进行探讨. 相似文献
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Lakshminarayana Polavarapu Andrea La Porta Sergey M. Novikov Marc Coronado‐Puchau Luis M. Liz‐Marzán 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(15):3065-3071
The translation of a technology from the laboratory into the real world should meet the demand of economic viability and operational simplicity. Inspired by recent advances in conductive ink pens for electronic devices on paper, we present a “pen‐on‐paper” approach for making surface enhanced Raman scattering (SERS) substrates. Through this approach, no professional training is required to create SERS arrays on paper using an ordinary fountain pen filled with plasmonic inks comprising metal nanoparticles of arbitrary shape and size. We demonstrate the use of plasmonic inks made of gold nanospheres, silver nanospheres and gold nanorods, to write SERS arrays that can be used with various excitation wavelengths. The strong SERS activity of these features allowed us to reach detection limits down to 10 attomoles of dye molecules in a sample volume of 10 μL, depending on the excitation wavelength, dye molecule and type of nanoparticles. Furthermore, such simple substrates were applied to pesticide detection down to 20 ppb. This universal approach offers portable, cost effective fabrication of efficient SERS substrates at the point of care. This approach should bring SERS closer to the real world through ink cartridges to be fixed to a pen to create plasmonic sensors at will. 相似文献
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Leena Nebhani Christopher Barner‐Kowollik 《Advanced materials (Deerfield Beach, Fla.)》2009,21(34):3442-3468
The performance of solid substrates is not only governed by their molecular constitution, but is also critically influenced by their surface constitution at the solid/gas or solid/liquid interface. In here, we critically review the use of orthogonal chemical transformations (so‐called click chemistry) to achieve efficient surface modifications of materials ranging from gold and silica nanoparticles, polymeric films, and microspheres to fullerenes as well as carbon nanotubes. In addition, the functionalization of surfaces via click chemistry with biomolecules is explored. Although a large host of reactions fulfilling the click‐criteria exist, pericyclic reactions are most frequently employed for efficient surface modifications. The advent of the click chemistry concept has led—as evident from the current literature—to a paradigm shift in current approaches for materials modification: Away from unspecific and nonselective reactions to highly specific true surface engineering. 相似文献
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Teng Qiu Wenjun Zhang Xianzhong Lang Yongjin Zhou Tiejun Cui Paul K. Chu 《Small (Weinheim an der Bergstrasse, Germany)》2009,5(20):2333-2337
A convenient nanoscale technique is reported for the fabrication of highly ordered hemispherical silver nanocap arrays templated by porous anodic alumina (PAA) membranes as robust and cost‐efficient surface‐enhanced Raman scattering (SERS) substrates. This geometry produces a high Raman signal due to its periodic hexagonal arrangements and control of the gap between the nanostructures in the sub‐10‐nm regime. The surface structure can be tuned further to optimize the enhancement factor according to optional PAA fabrication and silver deposition parameters. Finite‐difference time‐domain calculations indicate that the structure may possess excellent SERS characteristics due to the high density and abundance of hot spots. 相似文献
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A Hierarchically Ordered Array of Silver‐Nanorod Bundles for Surface‐Enhanced Raman Scattering Detection of Phenolic Pollutants 下载免费PDF全文
Chuhong Zhu Guowen Meng Peng Zheng Qing Huang Zhongbo Li Xiaoye Hu Xiujuan Wang Zhulin Huang Fadi Li Nianqiang Wu 《Advanced materials (Deerfield Beach, Fla.)》2016,28(24):4871-4876
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A Fast and Efficient Replacement of CTAB with MUA on the Surface of Gold Nanorods Assisted by a Water‐Immiscible Ionic Liquid 下载免费PDF全文
Linjia Su Song Hu Li Zhang Zhuoran Wang Weiping Gao Jing Yuan Minghua Liu 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(11)
The synthesis and surface modification of gold nanorods (GNRs) is one of the most important and basic issues in nanoscience. Most of the widely investigated GNRs are coated with a cetyltrimethylammonium bromide(CTAB) bilayer. Here, a highly efficient method is proposed to replace CTAB from the surface of GNRs with a bifunctional 11‐mercaptoundecanoic acid in order to decrease the possible toxicity caused by CTAB. This ligand exchange is achieved in a biphasic mixture of an aqueous solution and a water‐immiscible ionic liquid (IL), [BMIM][Tf2N]. That is, by mixing IL, mercaptoundecanoic acid (MUA)/IL (200 × 10?3 m ) and a concentrated aqueous solution of GNRs together, followed by vortex stirring for 90 s, CTAB‐capped GNRs with varying aspect ratios can be turned into corresponding MUA‐capped GNRs with the same aspect ratio. Furthermore, the formed MUA‐capped GNRs can be obtained in a large quantity and stored as powders for easy use. The MUA‐capped GNRs with improved biocompatibility and colloidal stability are well suited for further biological functionalization and potential applications. This IL‐assisted ligand exchange can reverse the surface charge, enhance the stability of GNRs, and suppress its cytotoxicity. 相似文献
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Van‐Qui Le Phuoc‐Anh Le Shu‐Chi Wu Yu‐Hong Lai Yan‐Gu Lin Kung‐Hwa Wei Ying‐Hao Chu Yu‐Lun Chueh 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(24)
Transparent flexible energy storage devices are considered as important chains in the next‐generation, which are able to store and supply energy for electronic devices. Here, aluminum‐doped zinc oxide (AZO) nanorods (NRs) and nickel oxide (NiO)‐coated AZO NRs on muscovites are fabricated by a radio frequency (RF) magnetron sputtering deposition method. Interestingly, AZO NRs and AZO/NiO NRs are excellent electrodes for energy storage application with high optical transparency, high conductivity, large surface area, stability under compressive and tensile strain down to a bending radius of 5 mm with 1000 bending cycles. The obtained symmetric solid‐state supercapacitors based on these electrodes exhibit good performance with a large areal specific capacitance of 3.4 mF cm?2, long cycle life 1000 times, robust mechanical properties, and high chemical stability. Furthermore, an AZO/NiO//Zn battery based on these electrodes is demonstrated, yielding a discharge capacity of 195 mAh g?1 at a current rate of 8 A g?1 and a discharge capacity of over 1000 cycles with coulombic efficiency to 92%. These results deliver a concept of opening a new opportunity for future applications in transparent flexible energy storage. 相似文献
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氟橡胶的表面粘接改性 总被引:1,自引:0,他引:1
用紫外线、臭氧、紫外线-臭氧处理6、0Co-γ射线辐射及苯乙烯/丙烯酸接枝方法,对粘接性差的氟橡胶表面进行改性。通过研究氟胶与金属粘接的剪切强度,考察了改性效果。结果表明,用60Co-γ射线进行辐射接枝丙烯酸后粘接性能最好,达到了11.04 MPa,比未改性的提高了50.8%。SEM表明,经表面改性处理后,氟胶表面粗糙程度均增加。电子能谱观察和FT-IR证明了改性后的氟胶表面引入了含N、O的极性基团。 相似文献
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钛溶胶表面修饰氧化铝空心球 总被引:2,自引:0,他引:2
本论文采用湿化学方法引入钛溶胶对氧化铝空心球表面进行修饰改性,并利用SEM、XRD和自制测耐压设备等手段对比研究了氧化铝空心球表面修饰改性前后表面结构和强度变化情况。以此为提高氧化铝空心球在铝工业炉中的应用价值提供实验依据。实验结果表明:钛溶胶在氧化铝空心球表面形成薄膜结构。在高温(1350℃)处理过程中,钛溶胶分解得到的金红石型二氧化钛与空心球基体原位反应生成钛酸铝,它可以修补空心球的缺陷位从而使空心球的强度得到提高。 相似文献
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Hao Huang Jia‐Hong Wang Weihong Jin Penghui Li Ming Chen Han‐Han Xie Xue‐Feng Yu Huaiyu Wang Zhigao Dai Xiangheng Xiao Paul K. Chu 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(19):4012-4019
Common methods to prepare SERS (surface‐enhanced Raman scattering) probes rely on random conjugation of Raman dyes onto metal nanostructures, but most of the Raman dyes are not located at Raman‐intense electromagnetic hotspots thus not contributing to SERS enhancement substantially. Herein, a competitive reaction between transverse gold overgrowth and dye conjugation is described to achieve site selective conjugation of Raman dyes to the hotspots (ends) on gold nanorods (GNRs). The preferential overgrowth on the nanorod side surface creates a barrier to prevent the Raman dyes from binding to the side surface except the ends of the GNRs, where the highest SERS enhancement factors are expected. The SERS enhancement observed from this special structure is dozens of times larger than that from conjugates synthesized by conventional methods. This simple and powerful strategy to prepare SERS probes can be extended to different anisotropic metal nanostructures with electromagnetic hotspots and has immense potential in in‐depth SERS‐based biological imaging and single‐molecule detection. 相似文献