疏水性半导体量子点的二氧化硅修饰及其应用
发布时间：2018-10-11 08:50
【摘要】：由于纳米量子点杰出的特性使得制备高质量的量子点的方法得到了快速的发展,尤其是采用有机溶液合成法可以制备出多种高量子效率的量子点。为了使量子点在相关的领域具有更好的应用性能,须对亲油性(疏水性)的量子点进行适当的表面修饰。本论文的主要工作就是采用硅烷试剂对疏水性量子点进行表面修饰研究,并把修饰后的量子点均匀分散到二氧化硅基体中去,为其作为发光材料应用进行了探索。本论文主要开展了以下的工作:(1)疏水性量子点的二氧化硅表面修饰研究使用原硅酸四乙酯(TEOS)、3-氨基丙基三甲氧基硅烷(APS)和3-巯基丙基三甲氧基硅烷(MPS)分别对疏水性的Cd Se/Cd Zn S量子点(表面配体为油酸)进行表面修饰。通过调整硅烷剂在浓度、反应时间等其他诸多条件,可以有效的改善量子点在二氧化硅修饰中的荧光猝灭问题,并能确保修饰后的量子点在进一步应用时仍然保持原有的光谱特性及较高的荧光强度。(2)荧光复合薄膜的制备及其性能研究利用TEOS和MPS分别对疏水性的Cd Se/Cd Zn S量子点进行表面修饰,通过层层自组装法(self-assembly method)制备具有-Si O2-QDs-的层状结构的复合荧光薄膜。该薄膜随着自组装层数的增加其荧光强度显著的增加。量子点在薄膜中分布均匀,浓度可以高达2.62×10-12 mol/cm2。所制备的荧光复合薄膜还具有良好的透明度和热稳定性。(3)荧光凝胶玻璃的制备及其性能研究利用APS直接对疏水性的Cd Se/Cd Zn S量子点进行表面修饰,制备成含有QDs的溶胶,最终获得了透明的高荧光Si O2-QDs凝胶玻璃。研究发现对于不同晶体结构的Cd Se/Cd Zn S量子点,使用APS进行表面修饰得到的凝胶玻璃的量子效率有显著的不同;所制备的荧光凝胶玻璃较有较高的量子效率、均匀的分散度、良好的透明度以及高的热稳定性能。(4)包含多个量子点的二氧化硅荧光纳米球的制备在使用TEOS对疏水性QDs表面修饰的基础上,我们采用变异的“St?ber法”将多个修饰后的疏水性QDs成功的包覆于二氧化硅纳米球内,且所制备的红色发光的二氧化硅纳米球的量子效率为31%。
[Abstract]:Due to the outstanding properties of nanometer quantum dots, the methods of preparing high quality quantum dots have been developed rapidly. Especially, many kinds of quantum dots with high quantum efficiency can be prepared by organic solution synthesis. In order to improve the application performance of quantum dots in related fields, it is necessary to modify the surface of hydrophilic (hydrophobic) quantum dots. The main work of this thesis is to study the surface modification of hydrophobic quantum dots by using silane reagent, and disperse the modified quantum dots evenly into silica matrix, and explore their applications as luminescent materials. The main work of this thesis is as follows: (1) the surface modification of hydrophobic quantum dots using tetraethyl silicate (TEOS), 3-aminopropyl trimethoxysilane (APS) and 3-mercapto propyl trimethoxysilane (MPS) to hydrophobicity respectively The surface of Cd Se/Cd Zn S quantum dots (surface ligand is oleic acid) was modified. By adjusting the concentration, reaction time and other conditions of silane, the fluorescence quenching of quantum dots in silica modification can be effectively improved. And it can ensure that the modified QDs can maintain the original spectral characteristics and high fluorescence intensity in the further application. (2) the preparation and properties of fluorescent composite films; the study on the hydrophobic Cd Se/Cd Zn S content of TEOS and MPS respectively Surface modification of the subpoints, Multilayer fluorescent films with Si O 2-QDs- were prepared by layer-by-layer self-assembly (self-assembly method) method. With the increase of the number of self-assembled layers, the fluorescence intensity of the film increases significantly. The quantum dots are uniformly distributed in the films with concentrations up to 2.62 脳 10 ~ (-12) mol/cm2.. (3) preparation of fluorescent gel glass and its properties; Surface modification of hydrophobic Cd Se/Cd Zn S quantum dots directly by APS to prepare QDs sol. Finally, transparent high fluorescence Si O2-QDs gel glass was obtained. It is found that for Cd Se/Cd Zn S quantum dots with different crystal structure, the quantum efficiency of the gel glass modified by APS is significantly different, and the fluorescent gel glass has higher quantum efficiency and uniform dispersion. Good transparency and high thermal stability. (4) the preparation of silica fluorescent nanospheres containing multiple quantum dots is based on the surface modification of hydrophobic QDs using TEOS. We successfully coated several modified hydrophobic QDs onto silica nanospheres by mutated "St?ber method", and the quantum efficiency of the red luminescent silica nanospheres was 31.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB306;O613.72
本文编号：2263577
[Abstract]:Due to the outstanding properties of nanometer quantum dots, the methods of preparing high quality quantum dots have been developed rapidly. Especially, many kinds of quantum dots with high quantum efficiency can be prepared by organic solution synthesis. In order to improve the application performance of quantum dots in related fields, it is necessary to modify the surface of hydrophilic (hydrophobic) quantum dots. The main work of this thesis is to study the surface modification of hydrophobic quantum dots by using silane reagent, and disperse the modified quantum dots evenly into silica matrix, and explore their applications as luminescent materials. The main work of this thesis is as follows: (1) the surface modification of hydrophobic quantum dots using tetraethyl silicate (TEOS), 3-aminopropyl trimethoxysilane (APS) and 3-mercapto propyl trimethoxysilane (MPS) to hydrophobicity respectively The surface of Cd Se/Cd Zn S quantum dots (surface ligand is oleic acid) was modified. By adjusting the concentration, reaction time and other conditions of silane, the fluorescence quenching of quantum dots in silica modification can be effectively improved. And it can ensure that the modified QDs can maintain the original spectral characteristics and high fluorescence intensity in the further application. (2) the preparation and properties of fluorescent composite films; the study on the hydrophobic Cd Se/Cd Zn S content of TEOS and MPS respectively Surface modification of the subpoints, Multilayer fluorescent films with Si O 2-QDs- were prepared by layer-by-layer self-assembly (self-assembly method) method. With the increase of the number of self-assembled layers, the fluorescence intensity of the film increases significantly. The quantum dots are uniformly distributed in the films with concentrations up to 2.62 脳 10 ~ (-12) mol/cm2.. (3) preparation of fluorescent gel glass and its properties; Surface modification of hydrophobic Cd Se/Cd Zn S quantum dots directly by APS to prepare QDs sol. Finally, transparent high fluorescence Si O2-QDs gel glass was obtained. It is found that for Cd Se/Cd Zn S quantum dots with different crystal structure, the quantum efficiency of the gel glass modified by APS is significantly different, and the fluorescent gel glass has higher quantum efficiency and uniform dispersion. Good transparency and high thermal stability. (4) the preparation of silica fluorescent nanospheres containing multiple quantum dots is based on the surface modification of hydrophobic QDs using TEOS. We successfully coated several modified hydrophobic QDs onto silica nanospheres by mutated "St?ber method", and the quantum efficiency of the red luminescent silica nanospheres was 31.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB306;O613.72
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