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将没有双亲性的电荷转移配合物TMB·TCNQ (TMB:3, 3′,5,5′-Tetramethylbenzidine;TCNQ:7,7,8,8-tetracyanoquinodimethane)通过与硬脂酸混合组装制备了混合LB膜。TMB·TCNQ和硬脂酸的摩尔比例在1∶1, 1∶2和1∶3的情况下都可以成功进行组装。利用紫外-可见-近红外光谱、透射和掠角反射红外光谱、X射线衍射以及原子力显微镜研究了混合LB膜中各组分的结构、分子取向和表面形貌等。研究结果表明,混合LB膜中的TMB·TCNQ是混合堆积排列的,电荷转移度ρ约为0.35。配合物中的电子给体TMB和电子受体TCNQ分子的苯环平面都垂直于基底表面。硬脂酸的碳氢长链以一定角度倾斜于基底表面。混合LB膜的小角X射线衍射图中出现了两组衍射峰。混合比例为1∶1的单层和多层LB膜中出现纳米棒和微粒,而且,纳米棒和粒子的数量随着LB膜层数的增加而增多。 相似文献
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纳米粒子的自组装和有序组装膜的结构与性质近年来受到了人们的广泛关注,纳米粒子的表面结构与性质对由其组装成的有序膜的结构与性质有直接的影响。文章报道了利用自组装技术制备的银纳米粒子与双亲有机分子的单层和多层复合LB膜,通过吸收光谱和表面增强拉曼光谱研究了银纳米粒子与吸附分子间的相互作用,探讨了复合膜的成膜特性及银纳米粒子的拉曼增强特性。十八胺/银粒子复合LB膜的吸收光谱及拉曼光谱显示,十八胺分子与银纳米粒子表面的活位通过NH2中的氮原子以复合体的形式结合;同时,在激发光的作用下复合体可能存在光催化过程。根据银粒子复合LB膜的实验结果,十八胺和十八酸之间的反应产物在复合膜中起空间位阻作用,与银粒子表面的相互作用较弱。 相似文献
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铁纳米粒子样品系采用气体蒸发法制备,用透射电子显微镜观察其结晶形态和粒径大小,采用X射线衍射、电子衍射、X射线光电子能谱和俄歇电子能谱等多种分析手段详细分析了粒子表面氧化膜的组成、结构和厚度及其稳定性,提出了铁纳米粒子组成和结构模型。结果发现铁纳米粒子本身的晶体结构与普通α-Fe是一致的,为体心立方结构,粒子表面存在约3nm厚的双层氧化膜,外面一层为γ-Fe2O3,厚度约为1nm。里面一层为Fe3O4,厚度约为2nm,
关键词: 相似文献
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由有机LB膜技术发展了一种制备组分、厚度可控的无机超薄陶瓷膜的方法 .以Zr、Y的 β 二酮络合物的作为“表面离子”代替传统的亚相离子 ,沉积它们与花生酸的混合LB膜 .并将它作为前驱物 ,经臭氧处理和热处理 ,成功制得了Y2 O3 稳定的立方相ZrO2 超薄膜 (YSZ) .用X射线衍射 (XRD)、X射线光电子能谱 (XPS)等手段研究了YSZ薄膜的相结构和其组成 .结果表明 ,超薄陶瓷膜中Zr与Y的含量比率控制得很好 ,且形成Y2 O3 稳定的立方相ZrO2 .说明这种方法可以成功地用来制备组分和膜厚均可控的纳米陶瓷膜 . 相似文献
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酞菁铜衍生物在酞菁酮—氧化铁纳米粒子交替LB膜中的分子取向 总被引:1,自引:0,他引:1
通过Langmuir-Blodett技术制备了酞菁酮-氧化铁纳米粒子交替LB膜,利用偏振紫外-可见光谱对酞菁铜衍生物在不同制膜条件下所制得的交替膜中的分子取向进行了研究。结果表明,在同一氧化铁溶胶亚相中,随着表面压的增大,或在相同的表面压下,随着亚相中氧化铁浓度的减小,酞菁铜分子在其复合LB膜中倾斜程度变大。 相似文献
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通过Langmuir Blodgett技术制备了酞菁铜 氧化铁纳米粒子交替LB膜 ,利用偏振紫外 可见光谱对酞菁铜衍生物在不同制膜条件下所制得的交替膜中的分子取向进行了研究。结果表明 ,在同一氧化铁溶胶亚相中 ,随着表面压的增大 ,或在相同的表面压下 ,随着亚相中氧化铁浓度的减小 ,酞菁铜分子在其复合LB膜中倾斜程度变大。 相似文献
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表面活性剂包埋的硫化锌纳米粒子LB膜的研究 总被引:2,自引:0,他引:2
采用LB膜技术制备了表面活性剂包埋的硫化锌纳米粒子多层膜,并利用小角X射线衍射、光电子能谱、原子力显微镜和透射电镜春结构进行了表征。结果表明制成的ZnL纳米粒子LB膜为一维准超晶格。 相似文献
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微波辅助法制备纤维状NaFeS2纳米粒子及其XPS研究 总被引:1,自引:1,他引:0
常温下用微波辅助法制得了直径小于10nm的纤维状NaFeS2 三元化合物纳米粒子,并用X射线粉末衍射、透射电子显微镜、选区电子衍射和X射线光电子能谱对纳米微粒进行了表征。XPS能谱分析表明:产物中含有Na ,Fe,S三种元素,其比值为Na∶Fe∶S =1∶1 1∶1 9。探讨了纤维状NaFeS2 纳米粒子的形成机理。 相似文献
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Core–shell CdS/ZnS nanoparticles in arachidic acid film were prepared through a novel Langmuir–Blodgett (LB) approach. Post-deposition treatment of the precursor LB multilayers of cadmium arachidate with H2S gas followed by intercalation of Zn2+ ions and further sulfidation result in the formation of CdS/ZnS nanoparticles in the LB film. The formation of these nanoparticles and resulting changes in layered structures were studied by FTIR and X-ray reflection measurements. The optical properties were studied using UV–vis absorption and photoluminescence spectroscopy. A red-shift in the absorption spectrum and enhancement of CdS excitonic emission together with reduction of surface states emission suggest that after the intercalation step, a thin layer of ZnS surrounds the CdS nanoparticles, thus forming a core–shell structure. Subsequent to the second sulfidation, a further red-shift in absorption suggests the formation of a thicker ZnS coating on CdS. Electron diffraction of CdS nanoparticles coated with thicker ZnS showed the diffraction patterns of only ZnS, as expected for core–shell structures. 相似文献
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采用微波加热加压法和静电吸附自组装法在石英玻璃表面制备了银包覆金纳米粒子薄膜,利用原子力显微镜分析了薄膜的表面形态和结构,测定结晶紫分子在薄膜表面的拉曼光谱。结果表明,银包覆金纳米粒子薄膜具有很强的表面增强拉曼散射效应(SERS)活性和稳定性。 相似文献
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A. Milekhin M. Friedrich D.R.T. Zahn L. Sveshnikova S. Repinsky 《Applied Physics A: Materials Science & Processing》1999,69(1):97-100
Structures with CdS quantum dots produced by the Langmuir–Blodgett (LB) technique were investigated by Raman, IR, and UV spectroscopies.
The confinement effect of longitudinal optical (LO) phonons in CdS quantum dots was investigated by Raman spectroscopy. Surface
vibrational modes of CdS quantum dots were observed in IR spectra. It was shown experimentally that the frequency of the surface
vibrational modes depends on the properties of the surrounding media. An average size of CdS quantum dots of about 3–6.4 nm
was obtained from the analysis of UV measurements.
Received: 1 February 1999 / Accepted: 1 April 1999 / Published online: 19 May 1999 相似文献
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X.L. Tong D.S. Jiang W.B. Hu Z.M. Liu M.Z. Luo 《Applied Physics A: Materials Science & Processing》2006,84(1-2):143-148
Two kinds of cadmium sulfate (CdS) thin films have been grown at 600 °C onto Si(111) and quartz substrates using femtosecond pulsed laser deposition (PLD). The influence of substrates on the structural and optical properties of the CdS thin films grown by femtosecond pulsed laser deposition have been studied. The CdS thin films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), photoluminescence (PL) and Raman spectroscopy. Although CdS thin films deposited both on Si(111) and quartz substrates were polycrystalline and hexagonal as shown by the XRD , SEM and AFM results, the crystalline quality and optical properties were found to be different. The size of the grains for the CdS thin film grown on Si(111) substrate were observed to be larger than that of the CdS thin film grown on quartz substrate, and there is more microcrystalline perpendicularity of c-axis for the film deposited on the quartz substrate than that for the films deposited on the Si substrate. In addition, in the PL spectra, the excitonic peak is more intense and resolved for CdS film deposited on quartz than that for the CdS film deposited on Si(111) substrate. The LO and TO Raman peaks in the CdS films grown on Si(111) substrate and quartz substrate are different, which is due to higher stress and bigger grain size in the CdS film grown on Si(111) substrate, than that of the CdS film grown on the amorphous quartz substrate. All this suggests that the substrates have a significant effect on the structural and optical properties of thin CdS films. PACS 81.15.Fg; 81.05.Ea; 78.20.-e; 78.67.-n; 42.62.-b 相似文献
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In this paper, we reported an investigation on a new photoelectrode of quantum dots-sensitized solar cell (QDSC) combining indium-tin-oxide (ITO) mesoporous film and CdS quantum dots (QDs). The ITO mesoporous film was prepared by doctor-blade technique and CdS QDs attached on ITO mesoporous film were synthesized by successive ionic layer adsorption and reaction method. X-ray diffraction, field emission scanning electron microscopy, transmission electron microscope, X-ray spectroscopy and UV-vis spectroscopy were used to characterize the samples. The results indicated that the ITO mesoporous film was uniform, crack-free and highly porous. And absorbance in visible region was enhanced after the deposition of CdS QDs on ITO mesoporous film. The photoelectrochemical property of the CdS QDs-sensitized ITO mesoporous film photoelectrode was investigated by forming a photoelectrochemical cell. Photocurrent-voltage measurement showed that the photoelectrode was efficient in the cell as working electrode. 相似文献
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The use of liquid-crystal (LC) cells for the visualization of the Langmuir-Blodgett (LB) film structure is described. Images appearing in LC cells upon LB film application are presented. The images are analyzed in relation to the LB film structure (application conditions) and to the relief formed by indium tin oxide (ITO) electrodes. 相似文献
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Wanquan Jiang Cuifeng Jiang Zhen Cao Xinglong Gong Zhong Zhang 《Journal of Physics and Chemistry of Solids》2009,70(3-4):782-786
A new hollow sphere photocatalyst has been fabricated by combining Fe3O4 with nanoparticulate CdS. Their microstructures and photocatalytic behavior were examined by X-ray powder diffraction, transmission electron microscope, scanning electron microscope and ultraviolet and visible spectroscopy. These hollow nanostructures displayed superparamagnetism at room temperature. It showed higher activity on hollow sphere than solid particle as the catalysis result. 相似文献
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Langmuir Blodgett (LB) process is an important route to the development of organized molecular layered structures of a variety
of organic molecules with suitably designed architecture and functionality. LB multilayers have also been used as templates
and precursors to develop nano-structured thin films. In this article, studies on the molecular packing and three-dimensional
structure of prototypic cadmium arachidate (CdA), zinc arachidate (ZnA) and mixed CdA-ZnA LB multilayers are presented. The
formation of semiconducting nano-clusters of CdS, ZnS and CdxZn1−xS alloys within the organic multilayer matrix, using arachidate LB multilayers as precursors is also discussed. 相似文献