稀土掺杂氟化物纳米功能材料的制备及发光特性研究

发布时间：2018-03-01 20:03

本文关键词： 纳米材料氟化物稀土掺杂上转换能量传递生物成像　出处：《中国计量大学》2016年硕士论文　论文类型：学位论文

【摘要】：近几年迅速崛起的纳米科技受到了越来越多人的关注,特别是在生物成像和纳米医药领域的应用。为了充分发挥纳米材料的潜能,需要进一步探究其合成方法和物理化学性质。稀土掺杂的无机纳米材料是典型的纳米材料之一,可应用于很多领域,尤其是体外实验、生物成像以及病情诊断。由于稀土掺杂氟化物纳米晶具有其他上转换基质材料无法比拟的优势,使得这种基质被推向了目前研究方向的前沿。本文以共沉淀法合成了氟化物纳米晶,系统探讨稀土离子掺杂浓度、种类以及稀土离子半径对纳米晶的光学性能影响,结合物相及发光性能的测试表征,系统的探讨了稀土离子之间的能量传递过程。选用声子能低的NaYF_4纳米晶作基质,以油酸为表面活性剂用共沉淀法分别合成了不同离子掺杂浓度的Ho~(3+)/Yb~(3+)、Tm~(3+)/Yb~(3+)、Er~(3+)/Yb~(3+)共掺NaYF_4纳米粉体,结合XRD和SEM分析,成功制备了六方相NaYF_4纳米晶且分散性良好。分别用980 nm半导体激光器激发样品,可以得到400-850 nm波段的上转换发光和1000-2000 nm波段的近红外下转移光谱。将合成后β-NaYF_4:20%Yb~(3+),3%Er~(3+)纳米颗粒用单波长980 nm激光激发,可以获得温度传感和可见及近红外(NIR)区域成像的双模功能。此外,我们将合成后的纳米颗粒表面包覆一层二氧化硅壳层从而使合成的纳米材料具有生物相容性。用同样的共沉淀合成法,在控制反应条件和掺杂浓度一致的情况下制备出几种Er~(3+)-Yb~(3+)共掺的NaLnF_4基质,其中Er~(3+)离子掺杂浓度为2 mol.%,Yb~(3+)离子掺杂浓度为20 mol.%。结合XRD和SEM分析,制备出的NaLnF_4纳米颗粒为混合相,且尺寸相差较大。分别用980 nm半导体激光器激发样品,可以得到一系列上转换发射光谱图,其中颗粒最小的NaLuF_4对应上转换发光强度最强,具有较好的研究前景。用同样的制备条件合成一系列Er~(3+)、Yb~(3+)单掺及共掺NaLuF_4纳米晶体,XRD测试表明在增加原料总量的情况下只能制备出立方相的NaLuF_4纳米晶体,用980nm激光激发获得一系列上转换发射光谱,可当Er~(3+)单掺NaLuF_4时,上转换发光强度随着Er~(3+)离子浓度升高逐渐增强;固定Yb~(3+)离子掺杂浓度为20mol.%,增加Er~(3+)离子掺杂浓度时,上转换发光强度随着Er~(3+)离子浓度升高先增强后减弱。最后分析不同Er~(3+)离子掺杂浓度的光强差异,最后分析了其能量传递过程。
[Abstract]:The rapid rise in recent years, nano technology has attracted more and more attention, especially the application in biological imaging and nano medicine field. In order to give full play to the potential of nano materials, need to further explore the synthesis methods and the physical and chemical properties. The inorganic nano material doped with rare earth ions is one of the typical nano materials, can be applied to many the field, especially in vitro, biological imaging and diagnosis. Because of the rare earth doped fluoride nanocrystals with other conversion matrix material has the incomparable advantage, the matrix was pushed to the forefront of current research direction. In this paper, co precipitation method synthesis of fluoride nanocrystals, the system of rare earth ions doping concentration, type and influence the radius of rare earth ions on the optical properties of nanocrystals, binding phase and characterization of the luminescence properties of the system of rare earth ions between the The amount of the transfer process. The NaYF_4 nanocrystalline low phonon energy matrix, using oleic acid as surfactant were synthesized by coprecipitation method with different doping concentration of Ho~ (3+) /Yb~ (3+), Tm~ (3+) /Yb~ (3+), Er~ (3+) /Yb~ (3+) doped NaYF_4 nanometer powder body, analysis combined with XRD and SEM, six phase NaYF_4 nanocrystals and good dispersibility were prepared respectively. Using the 980 nm semiconductor laser excitation of the sample, can get 400-850 nm band near infrared luminescence and 1000-2000 nm band transfer spectra. The combined beta -NaYF_4:20%Yb~ (3+), 3%Er~ (3+) nanoparticles with single wavelength 980 nm laser excitation, can obtain the temperature sensing and visible and near infrared (NIR) dual function area imaging. In addition, we will after the synthesis of nano particles coated with a layer of silica shell so that the synthesis of nano materials with biocompatibility. With the same co precipitation Starch synthesis, preparation of several Er~ in controlling the reaction conditions and doping concentration under the same circumstances (3+) -Yb~ (3+) NaLnF_4 matrix Co doped, Er~ (3+) ion doping concentration is 2 mol.%, Yb~ (3+) ion doping concentration is 20 mol.%. according to the analysis of XRD and SEM, NaLnF_4 nanoparticles the prepared mixed phase, and the size is large. With 980 nm semiconductor laser excitation of the sample, we can get a series of upconversion emission spectra, which NaLuF_4 the smallest particles corresponding upconversion luminescence intensity is the strongest, has good prospects for research. The preparation conditions of the synthesis of a series of Er~ with the same system (3+) (3+, Yb~) single doped and Co doped NaLuF_4 nanocrystals, XRD tests show that the increase in the total amount of raw materials under the condition of only prepared cubic phase NaLuF_4 nanocrystals, obtained a series of emission spectrum conversion by 980nm laser excitation, when Er~ (3+) doped NaLuF_4, up conversion The luminescence intensity with Er~ (3+) ion concentration increased; the fixed Yb~ (3+) ion doping concentration is 20mol.%, increased Er~ (3+) ion doping concentration, the intensity of upconversion luminescence with Er~ (3+) ion concentration increases firstly and then decreases. Finally, the analysis of different Er~ (3+) ions concentration differences of intensity at last, analyzed the energy transfer process.

【学位授予单位】：中国计量大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB383.1;TB34

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