纳米磁性荧光复合材料制备工艺的研究

发布时间：2018-03-26 12:13

本文选题：量子点　切入点：磁流体　出处：《苏州科技学院》2015年硕士论文

【摘要】：纳米级材料因为自身的粒度减小具有了特异而又超常的热学方面、电学方面、力学方面、光学方面、磁学方面和化学方面的各种性质。当粒子的粒度在不同维度时,一维、二维或者是多维,而且粒度的大小比电子的传输自由程小时,它们的各种性质都出现本质性的变化。其中最具有实用的价值和发展的前景有荧光量子点和磁性纳米微球。多种纳米粒子相互的复合可以达到从纳米小颗粒到功能化器件的一个转化,而且通着这种复合还能把每种纳米粒子的性能进行很好的整合。所以对于双功能纳米复合物质的探索已然成为化学、材料学等方面的研究热潮。半导体荧光量子点和磁性纳米微球的整合是一个很好的示范,两者之间的整合可以使生物医学中的荧光标记和外加磁场分离一步完成,这种纳米粒子间的整合将在很多方面发挥巨大的作用。兼具荧光和磁性的纳米复合微球即具有有磁性微球的外加磁场分离特点,又兼具量子点的荧光特性,具有很好的发展前景,有望在细胞的免疫检测、细胞或者组织分离、靶向治疗等领域得到广泛的应用。合成中主要通过静电吸引和键合,制备出四氧化三铁与水相量子点碲化镉复合物(Fe3O4/PMIDA@CdTe)和四氧化三铁与油相量子点硒化镉硫化镉的复合物(Fe3O4/PMIDA@CdSe/CdS)。针对该项研究,本文做了以下工作:(1)在水溶液中,运用共沉淀法,首先制备了四氧化三铁Fe3O4磁性微粒,再用一定量的聚乙二醇(TMAOH)表面活性剂使之形成亲水性较好的磁性纳米微球,并使Fe3O4表面带上功能性基团-OH。然后以制备好的亲水性较好的四氧化三铁为内核,再在其外层通过静电吸引的方法包上修饰剂双甘膦(PMIDA),使其表面带上功能性羧基-COOH,更大程度的提高了磁流体的水溶性。通过对修饰双甘膦(PMIDA)时的pH值、双甘膦的包覆温度,修饰剂双甘膦的浓度等的实验研究,得到了制备的最佳工艺。(2)制备水相的碲化镉(CdTe):通过三个步骤的化学胶体合成法,制备出了胶状的水相CdTe荧光量子点,再通过巯基乙酸(TGA)在其表面修饰巯基乙酸,使其带有功能性基团羧基。对制备过程中的前体浓度、Cd前体和Te前体结合温度、荧光强度等实验条件进行深度探究,得出了制备水相量子CdTe的最优方案。(3)油相中制备CdSe/CdS量子点:以油酸、液态石蜡这两种作为溶剂,制备出了油相的CdSe/CdS量子点,再用巯基乙酸(TGA)作为修饰剂,然后转移至PBS缓冲液中。通过对制备过程中的CdSe/CdS中Se和S浓度的研究、表面修饰剂的选取、荧光强度随保存时间的改变等实验条件进行深度探究,得出了制备水相量子的最优方案。(4)以乙二胺作连接剂,EDC作为活化剂,通过磁性微球Fe3O4表面的功能性基团羧基与量子点表面的羧基,通过化学键合,使得磁性Fe3O4纳米颗粒与荧光量子点相相结合,得到了磁性和荧光都可以达到应用级别的双功能纳米微球。通过TEM、红外分光光度计、热重分析仪、EDS、荧光分光光度计等各种表征。表征结果显示,制得的Fe3O4/PMIDA@CdTe和Fe3O4/PMIDA@CdSe/CdS磁性荧光纳米复合微球在水中分散性好。
[Abstract]:Nano materials because of their size decreases with the heat, specific and extraordinary electrical, mechanical, optical, magnetic and chemical properties. When the particle size in different dimensions, one-dimensional, two-dimensional or multidimensional, and the size of the electron transfer process than free hours, all their properties are essential changes. One of the most practical value and development prospects of fluorescent quantum dots and magnetic nanoparticles. Various nanoparticles can reach from nanometer particles to a transformation function of composite elements, and through the composite but also the performance of each integration is nanoparticles good. So to explore the dual function of nano composite material has become a research upsurge of chemistry, material science and so on. Fluorescent semiconductor quantum dots and magnetic nano micro The ball is the integration of a good demonstration, the integration between the two can be labeled in biomedicine and magnetic separation in one step, the integration between the nanoparticles will play a great role in many aspects. Both fluorescent and magnetic nano composite microspheres with magnetic field has the characteristics of separation of magnetic microspheres. Both the fluorescence property of quantum dots, have very good development prospects, is expected in the cell immune detection, cell or tissue separation, targeted therapy has been widely used in the synthesis. Mainly through the attraction and electrostatic bond prepared, ferroferric oxide and aqueous CdTe quantum dots composite (Fe3O4/PMIDA@CdTe) and Fe3O4 and oil phase composite quantum dot CdSe CDs (Fe3O4/PMIDA@CdSe/CdS). According to the study, this paper has done the following work: (1) in aqueous solution, using co precipitation method, The Fe3O4 Fe3O4 magnetic particles were prepared by a certain amount of polyethylene glycol (TMAOH) surfactant to form magnetic nanospheres with good hydrophilicity, and the functional groups on the surface of Fe3O4 and -OH. in the preparation of good good hydrophilicity of the Fe3O4 as the core, and then the outer package through the method of electrostatic attraction the modifier N-phosphonomethyliminodiacetic acid (PMIDA), the surface functional group of -COOH, the greater the degree of increase of the magnetic fluid. Based on a modified water soluble N-phosphonomethyliminodiacetic acid (PMIDA) values of pH coating temperature PMIDA, experimental study of modified agent concentration N-phosphonomethyliminodiacetic the optimal preparation process. (2) preparation of aqueous cadmium telluride (CdTe) by chemical colloidal synthesis of three steps, was prepared by aqueous CdTe QDs colloidal, by thioglycolic acid (TGA) on the surface modification of thioglycolic acid, the band A functional group of carboxyl. For the preparation of the precursor concentration in the process of Cd precursor and Te precursor with temperature, the fluorescence intensity of the experimental conditions such as in-depth exploration, and gives the optimal scheme for preparing aqueous quantum CdTe. (3) the oil phase preparation of CdSe/CdS quantum dots with oleic acid, the liquid paraffin two as solvent, we prepared the CdSe/CdS quantum dots are oil, and thioglycolic acid (TGA) as a modifier, and then transferred to the PBS buffer. Through the research on the preparation process of CdSe/CdS in Se and S concentration, surfactant selection, fluorescence intensity changes with storage time the experimental conditions for in-depth exploration, and gives the optimal scheme for preparing aqueous quantum. (4) with ethylenediamine as coupling agent, EDC as activator, the surface functional groups of carboxyl and quantum dots on the surface of Fe3O4 magnetic microspheres with carboxyl groups, by chemical bonding, the magnetic properties of Fe3O4 nanoparticles With the combination of fluorescent quantum dots, double function of nanoparticles obtained magnetic and fluorescent can achieve application level. By TEM, infrared spectrophotometer, thermogravimetric analyzer, EDS, fluorescence spectrophotometer. Various characterization results show that Fe3O4/PMIDA@CdTe and Fe3O4/PMIDA@CdSe/CdS nanometer magnetic fluorescent composite microspheres prepared by dispersion good in the water.

【学位授予单位】：苏州科技学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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