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溶胶-凝胶法制备光学杂化功能材料 总被引:9,自引:0,他引:9
在简述溶胶-凝胶法基本原理的基础上,介绍了设计杂化材料的原则及预掺杂法、后掺杂法和原位化学合成法三种溶胶-凝胶法制备光学杂化功能材料的途径;综述了稀土发光材料、波导材料和光致变色材料三种光学杂化功能材料,并结合国内外的研究提出开展光学杂化功能材料研究的重要方向. 相似文献
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单壁碳纳米管(SWNTs)由于具有独特的物理、化学性质,激起人们极大的研究兴趣。目前生产的SWNTs通常包含等量左旋和右旋对映异构体,无光学活性,极大地限制碳纳米管在光学和光电子领域的研究和应用。已报道的非共价法分离光学活性碳纳米管的方法主要有离子交换色谱法、nanotweezers选择法、密度梯度超高速离心法、共轭聚合物缠绕法和小分子吸附法。本文较为详尽地综述了非共价法分离光学活性碳纳米管的研究进展,对各种分离方法的机理进行阐述,并在此基础上分析这些方法和分离效果的关系,指导设计和合成新型的分离试剂。最后,本文还针对上述研究中存在的问题,提出了旋光性SWNTs分离技术的研究方向。 相似文献
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稀土氟化物微纳米材料制备方法的研究进展 总被引:1,自引:0,他引:1
稀土氟化物纳米材料由于其特殊的光、电、磁性质,在光学器件、显示、生物标记、光学晶体等领域有着广泛的应用,已成为材料科学领域的研究热点之一。目前研究者已用沉淀法、微乳液法、水热与溶剂热法、溶胶-凝胶法、微波法、超声波法、前驱体热解法、静电纺丝法等成功地制备出了纳米颗粒、纳米线、纳米膜、多面体纳米晶、复合结构纳米晶、核壳结构纳米材料等稀土氟化物纳米材料。本文总结了上述几种制备方法的研究进展,讨论了其优缺点,并结合课题组在稀土氟化物纳米材料制备方面的工作,对纳米稀土氟化物制备方法的发展方向做了展望。 相似文献
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将在溶液中表现出优良非线性光学和光限幅性能的铟酞菁及其二聚物嵌入到非光学活性的聚甲基丙烯酸甲酯(PMMA)中, 用传统的旋转涂膜法制备得到具有较高光学质量的复合物薄膜, 用开孔Z-扫描方法在532 nm 处研究了复合物薄膜材料的线性光学和非线性光学性能. 结果表明, 无论是铟酞菁单体还是轴向氧桥联的铟酞菁二聚物, 其PMMA复合材料的光限幅性能均显著优于相应的酞菁分子在溶液中的光限幅性能. 相似文献
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Bailar法是对八面体配合物立体异构体计数的较好方法之一,我们认为该法仍有改进之必要与可能。由Bailar法得到光学异构体需进行两步工作:一是列表、取舍,得到几何异构体;二是根据所得几何异构体的对称性质来确定其是否存在光学异构体。我们认为该法第一步所删去的重复构型中就包括了全部对映体的一半,再在第二步中找回这一半,这种步骤显然不甚合理。实际上只要修改部分取舍规则,便可以直接、同时得到所有几何异 相似文献
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溶胶-凝胶法制备含偶氮生色团的三阶非线性材料 总被引:1,自引:0,他引:1
通过溶胶-凝胶法制备了含三阶非线性光学发色团DRl9硅氧烷染料的有机-无机复合材料(3),其结构经1H NMR和IR表征.研究了pH值对3微观形态及光学性能的影响. 相似文献
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Recent developments in detection for microfluidic systems 总被引:1,自引:0,他引:1
Microfluidic systems have become more and more important in the field of analytical chemistry. Detection methods on these microsystems are essential for the identification and quantification of chemical species that are being analyzed. This review concentrates on the latest developments of optical detection methods and mass spectrometry in conjunction with microfluidic systems. Electrochemical methods are discussed in another review in the same issue of this journal. Within the optical detection section, topics such as multiplexed detection and the use of waveguides are discussed. Within the discussion of mass spectrometry, the main focus is on electrospray emitters as interfaces between microsystem and spectrometer. Apart from optical detection and mass spectrometry, other techniques such as flame ionization and nuclear magnetic resonance are also mentioned. 相似文献
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Yicun Huang Fanyong Yan Manman Fu Ruiqi Zhang Xuguang Zhou Jinxia Xu 《Journal of the Iranian Chemical Society》2017,14(1):157-176
Because some metal ions are highly toxic even at trace level, a constant demand of developing methods for monitoring and removing these metal ions is extremely urgent. Silica-based optical chemosensors are supposed as good alternatives to classical instrumental methods for detecting and adsorbing metal ions, due to their effect and lower price. Silica nanoparticles, silica gel and mesoporous silica are used as supporting platforms to fabricate optical chemosensors. They have certain properties containing high porosity and expectant adsorption capacity. Chromogenic-type and fluorogenic-type optical probes, such as azobenzene, naphthalimide and rhodamine, are grafted to the surface of silica-based materials by sol–gel reaction, the limit of detection, response time and selective properties of optical sensors are improved sequentially. In this paper, the articles of silica-based optical chemosensors are retrospected since 2008, describing silica-based optical sensors used for sensing metal ions. The sensing mechanism, optical phenomenon, detection limit, adsorption capacity and application are also reviewed. 相似文献
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Conductimetric and potentiometric detection in conventional and microchip capillary electrophoresis 总被引:1,自引:0,他引:1
Potentiometric detection is rarely used in separation methods but is promising for certain classes of analytes which can only with difficulty be quantified by more standard methods. Conductimetric detection of ions is very versatile and has recently received renewed interest spurned by the introduction of the capacitively coupled contactless configuration. Both are useful and complementary alternatives to the established optical detection methods, and to the more widely known electrochemical method of amperometry. The simplicity of the electrochemical methods makes them particularly attractive for microfabricated devices, but relatively little work has to date been carried out with regard to potentiometric and conductimetric detection. 相似文献
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Liu Y Gaskell KJ Cheng Z Yu LL Payne GF 《Langmuir : the ACS journal of surfaces and colloids》2008,24(14):7223-7231
Electrochemical methods are well suited for chemical detection in hand-held devices because they are simple, fast, and sensitive. However, electrochemical detection methods generally suffer from limitations in selectivity. We report a novel approach that enables electrochemically initiated reactions to generate optical signals that can be used to enhance the discriminating power for the electrochemical analysis of antioxidant food phenols. This spectroelectrochemical approach employs transparent electrodes coated with a film of the aminopolysaccharide chitosan. The phenolic analytes diffuse through the chitosan film to the electrode where they are anodically oxidized into electrophilic intermediates that undergo postelectrode reactions with the chitosan film. The postelectrode reaction was analyzed by FTIR and XPS, and this reaction was observed to impart optical properties (color and UV-visible absorbance) to the otherwise colorless and transparent chitosan film. We demonstrate that the optical signal generated from the postelectrode film reaction is selective for oxidized phenols, compared to that for unoxidized phenols or the nonphenolic antioxidant ascorbic acid. Furthermore, we demonstrate that the optical signal (film absorbance) can be correlated to the electrical signal (charge transferred). Finally, we use simple mixtures to demonstrate that the coupling of information from independent optical and electrical measurement modes can assist in the qualitative analysis of antioxidant phenols. Potentially, the postelectrode film reaction may provide a selective and reagentless alternative to conventional colorimetric methods for detecting antioxidant phenols. In a broader perspective, this work suggests the potential for coupling independent detection modes (optical and electrical) to enhance the information content of sensor measurements. 相似文献
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Baltussen E Guijt RM van der Steen G Laugere F Baltussen S van Dedem GW 《Electrophoresis》2002,23(17):2888-2893
Nearly all analyses by capillary electrophoresis (CE) are performed using optical detection, utilizing either absorbance or (laser-induced) fluorescence. Though adequate for many analytical problems, in a large number of cases, e.g., involving non-UV-absorbing compounds, these optical detection methods fall short. Indirect optical detection can then still provide an acceptable means of detection, however, with a strongly reduced sensitivity. During the past few years, contactless conductivity detection (CCD) has been presented as a valuable extension to optical detection techniques. It has been demonstrated that with CCD detection limits comparable, or even superior, to (indirect) optical detection can be obtained. Additionally, construction of the CCD around the CE capillary is straightforward and robust operation is easily obtained. Unfortunately, in the literature a large variety of designs and operating conditions for CCD were described. In this contribution, several important parameters of CCD are identified and their influence on, e.g., detectability and peak shape is described. An optimized setup based on a well-defined detection cell with three detection electrodes is presented. Additionally, simple and commercially available read-out electronics are described. The performance of the CCD-CE system was demonstrated for the analysis of peptides. Detection limits at the microM level were obtained in combination with good peak shapes and an overall good performance and stability. 相似文献
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酸氢根离子(HSO4)在生命、环境科学中发挥着非常重要的作用,进入环境后会污染环境,对人体造成危害.因此,选择性和高灵敏识别检测生物与环境样品中HSO4具有非常重要的意义.在众多的分析检测手段中,基于分子识别理念发展起来的光化学传感分子(探针)具有独特的优势.阴离子光化学传感体系以其选择性好、灵敏度高、易于实现在线分析,特别是可通过目视比色识别和原位检测等特点成为目前研究的热点.本文根据探针分子与HSO4之间的作用机理, 对近年来HSO4的光化学探针分子进行分类和总结,综述了HSO4光化学探针的研究进展,并对其应用前景与发展趋势进行了展望. 相似文献
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A miniaturized post-column fluorimetric detection cell for capillary separation methods based on optical fibers and liquid core waveguides (LCWs) is described. The main part of the detection cell is a fused-silica capillary coated with Teflon AF serving as an LCW. The optical fibers are used both for coupling the excitation source with the detection domain in the LCW and for the axial fluorescence collection from the LCW end. The latter fiber is connected with a compact CCD spectrometer that serves for the rejection of the scattered excitation light and for the fluorescence signal detection. The proposed design offers a compact fluorescence detector for various microcolumn separation techniques without optical elements such as filters or objectives. Moreover, its construction and optical adjustment are very simple and the whole system is highly miniaturized. The function of the detection cell is demonstrated by CE of amino acids labelled by fluorescein-based tags. Separations of different standard amino acid mixtures and plasma samples are presented. The comparison of plasma amino acid levels of individuals being in good health with those of patients with inherited metabolic disorders is also shown. 相似文献
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K. Niemax 《Fresenius' Journal of Analytical Chemistry》1990,337(5):551-556
Summary The application of laser spectroscopy in spectrochemistry requires excitation and detection schemes different from the estabolished optical spectrochemical methods. The most promising techniques developed in laser spectrochemistry are described and the analytical figures of merits are discussed. The very low absolute detection limits of the laser methods are required if trace elements have to be measured in microsamples. 相似文献