碲化镉量子点粉末的制备和物证检测应用

发布时间：2018-07-27 10:05

【摘要】： 诞生于20世纪80年代的纳米科学技术,经过近30年的发展取得了突破性的进展。其中,有关半导体纳米微晶的研究是纳米材料研究的一个重要方向。半导体纳米微晶,又称量子点,因其独特的零维结构显示出了特殊的理化性质及良好的光学性能。相比一般的有机荧光染料,量子点具有量子产率高、激发光谱宽、发射光谱窄、抗光漂白能力强、稳定性及生物兼容性较好等优点。因此,针对纳米量子点的合成和应用研究,受到了许多学科研究工作者的广泛关注。本论文共分为两部分,第一章是绪论,主要对量子点的基本概念、性质、结构和发光机理、合成方法及其应用等方面的内容进行了介绍。第二章是研究报告,共分为三小节,介绍了分别以谷胱甘肽(GSH)和巯基化壳聚糖为稳定剂合成量子点,并对其进行沉淀、离心、干燥等处理过程制备了能够长期稳定存在的量子点粉末,并应用其对非渗透性及渗透性不同客体上的潜在指纹进行显现,获得了良好的显现效果。同时还讨论了量子点与潜在指纹的相互作用的可能机理。现将研究报告部的内容简要介绍如下：一、GSH-capped CdS QDs溶液在潜在指纹显现中的应用这部分实验制备了水溶性的GSH-capped CdS QDs溶液,通过紫外-可见吸收光谱、荧光发射光谱、透射电子显微镜等表征方法对合成的量子点溶液进行表征,发现合成的量子点溶液具有优异的光学性能,透射电镜照片表明所合成的量子点近似球形,粒径分布均匀,在溶液中单分散性良好,同时讨论了反应时间对量子点粒径及发光颜色的影响。应用合成的量子点溶液对非渗透性客体玻璃上用“502”胶熏过的潜在指纹显现,获得了较好的显现效果,同时讨论了量子点与指纹作用的可能机理。二、GSH-capped CdTe QDs粉末的制备和指纹显现中的应用 GSH-capped CdS QDs溶液的发光颜色随合成时间的延长改变不明显,而GSH-capped CdTe QDs量子点随回流时间的延长经历了从绿色-黄色-橙色-红色-深红色的变化过程,颜色比较丰富。适合背景复杂客体上潜在指纹的显现。因此,本部分主要合成了GSH-capped CdTe QDs,并且将合成的量子点溶液进行离心、干燥等处理得到了不同发光颜色的具有优异光学性能的量子点粉末。再结合粉末法对玻璃、铝片、纸币、纸片上用“502”熏过及未熏过的潜在指纹进行显现,显现出的指纹清晰可辨,反差明显,效果良好。三、CTS-TGA-capped CdTe QDs粉末在潜在指纹显现中的应用对分子量为十万左右的壳聚糖水解得水溶性低分子量的壳聚糖,用巯基乙酸对其进行巯基化后作为合成CdTe QDs的稳定剂。荧光光谱表征表明,合成的量子点溶液最大发射波长为546nm,发射峰峰形基本对称,将合成的巯基化壳聚糖修饰的CdTe QDs溶液处理后得量子点粉末后,应用粉末对玻璃、铝片、铜片上用“502”熏过及未熏过的潜在指纹进行显现,均取得了明显的显现效果。
[Abstract]:Nanoscale science and technology, born in 1980s, have made breakthrough progress after nearly 30 years of development. Among them, the study of semiconductor nanocrystals is an important direction in the research of nanomaterials. Semiconductor nanocrystals, also known as quantum dots, show special physical and chemical properties and good light because of their unique zero dimensional structure. Compared with the general organic fluorescent dyes, quantum dots have the advantages of high quantum yield, wide excitation spectrum, narrow emission spectrum, strong anti photobleaching ability, good stability and biocompatibility. Therefore, the research on the synthesis and application of nanoscale quantum dots is widely concerned by many researchers.
This paper is divided into two parts. The first chapter is introduction. The basic concepts, properties, structure and luminescence mechanism, synthesis methods and applications of quantum dots are introduced. The second chapter is the study report, which is divided into three sections, and the synthesis of quantum dots with GSH and Mercapto chitosan as stabilizers is introduced. In the process of precipitation, centrifugation and drying, a quantum dot powder which can be stable for a long time has been prepared, and the potential fingerprint of different osmosis and permeability objects has been displayed. The possible mechanism of the interaction between the quantum dots and the latent fingerprints is also discussed. The content of the report department is briefly described as follows:
Application of GSH-capped CdS QDs solution in latent fingerprints
The water-soluble GSH-capped CdS QDs solution was prepared in this experiment. The synthesized quantum dot solution was characterized by UV visible absorption spectrum, fluorescence emission spectrum, transmission electron microscope and other characterization methods. It was found that the synthesized quantum dots solution had excellent optical properties. Transmission electron microscope photographs showed that the synthesized quantum dots were similar. The particle size distribution is uniform and the monodisperse in the solution is good. At the same time, the effect of the reaction time on the particle size and luminescence color of the quantum dots is discussed. The application of the synthesized quantum dots solution to the latent fingerprint of the non permeable guest glass with "502" glue is shown, and the quantum dots and the fingerprint are also discussed. The possible mechanism for use.
Two, preparation of GSH-capped CdTe QDs powder and application in fingerprint display.
The luminescence color of GSH-capped CdS QDs solution is not obvious with the prolongation of the synthesis time. While the GSH-capped CdTe QDs quantum dots have experienced the process of changing from green to orange to red to red and rich in color. It is suitable for the appearance of potential fingerprints on the complex background objects. Therefore, this part mainly syntheses the G. SH-capped CdTe QDs, and the synthesis of the quantum dot solution is centrifuged, drying and other treatment to obtain different luminous colors with excellent optical properties of quantum dots with excellent optical properties. Then the powder method is used to show the potential fingerprint of "502" and not smoked on glass, aluminum, paper, and paper. Obviously, the effect is good.
Three, the application of CTS-TGA-capped CdTe QDs powder in latent fingerprints.
Chitosan was hydrolyzed to a water-soluble low molecular weight chitosan with a molecular weight of about one hundred thousand. Mercapto acetic acid was used as a stabilizer for the synthesis of CdTe QDs. The fluorescence spectra showed that the maximum emission wavelength of the synthesized quantum dot solution was 546nm, the peak of the emission peak was symmetric, and the synthesized mercapto chitosan modified Cd After the Te QDs solution was treated with a quantum dot powder, the powder was used to show the potential fingerprint of "502" and not fumigating on the glass, aluminum and copper.
【学位授予单位】：陕西师范大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：O614.242;D918.2

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