超顺磁性纳米粒子簇的制备及弛豫性能研究

发布时间：2018-11-06 14:56

【摘要】：磁性纳米材料因具有独特的纳米材料特性及磁性能特性在生物医学领域中得到了广泛的研究。它们已经成为了疾病的诊断、治疗,以及特定病原体和生物物种分离的重要工具。磁性纳米材料所具有的这些独特的性能为医疗成像、免疫检测、药物输送等生物医学应用提供了新的平台和机遇,因此,研究磁性纳米复合材料具有重要的意义。磁性纳米复合材料的制备、结构、形貌、磁学性能以及弛豫性能在本文中做出了系统的研究。主要研究内容如下:Fe3O4纳米材料的制备及表征使用高温热分解油酸铁的方法制备出了Fe3O4纳米粒子,探究了油醇的用量及回流温度对其粒径的影响。所制样品通过XRD、激光粒度分析仪、磁强计等手段进行了表征。结果表明油醇用量越大,回流温度越低,Fe3O4纳米粒子的粒径越小。超顺磁性纳米粒子簇的制备及表征制备出氧化石墨烯功能化的超顺磁性纳米粒子簇。所制备的样品通过XRD、TEM、FT-IR、VSM、热重等手段进行了表征,结果表明该复合材料水溶性良好且具有超顺磁性。并对该复合材料进行了聚乙二醇进一步修饰,修饰后的复合材料在PBS缓冲溶液中具有良好的分散性和稳定性。采用硫醇点击化学法制备出了聚乙二醇功能化的四氧化三铁纳米复合材料,所得样品通过XRD、TEM、FT-IR、UV-vis、Raman等进行了表征。该制备方法条件温和,操作简便、后处理简单,制备出的产物在水或PBS缓冲溶液中稳定性和分散性良好。采用3.4-二羟基苯基丙酸作为中间体小分子制备出了聚乙烯亚胺功能化的四氧化三铁纳米粒子簇,所制样品通过TEM、FT-IR和Zeta电位等方法进行了表征和磁性能测试。该方法简单,反应条件温和,制备时间短,制备出的产物在水和PBS溶液中具有良好的分散性和稳定性。应用研究对多巴胺功能化的四氧化三铁纳米复合物和氧化石墨烯功能化四氧化三铁纳米粒子簇的弛豫行为进行了表征。得知随着铁离子浓度的增大,多巴胺功能化四氧化三铁纳米粒子的纵向弛豫时间减小且该物质的水溶液在10 m T下的R1值为0.65 m MS-1,在10 m T下水的时域信号在一定时间能随着极化时间的增长而增长,经拟合公式得自旋-晶格弛豫时间倒数为3.05S-1。氧化石墨烯功能化的磁性纳米粒子粒径较大者的r1和r2值均大于粒径较小者。
[Abstract]:Magnetic nanomaterials have been widely studied in biomedical field because of their unique properties of nanomaterials and magnetic properties. They have become important tools for the diagnosis, treatment, and separation of specific pathogens and biological species. These unique properties of magnetic nanomaterials provide new platforms and opportunities for biomedical applications such as medical imaging, immunoassay, drug delivery, etc. Therefore, the study of magnetic nanocomposites is of great significance. The preparation, structure, morphology, magnetic properties and relaxation properties of magnetic nanocomposites have been systematically studied in this paper. The main research contents are as follows: the preparation and characterization of Fe3O4 nanomaterials Fe3O4 nanoparticles were prepared by pyrolysis of ferric oleate at high temperature. The effects of the amount of oil alcohol and reflux temperature on the particle size were investigated. The samples were characterized by XRD, laser particle size analyzer and magnetometer. The results show that the larger the amount of oil alcohol, the lower the reflux temperature, the smaller the particle size of Fe3O4 nanoparticles. Preparation and characterization of superparamagnetic nanoparticles cluster the functional superparamagnetic nanoparticles cluster of graphene oxide were prepared. The samples were characterized by XRD,TEM,FT-IR,VSM, thermogravimetry. The results showed that the composites were water-soluble and superparamagnetic. The composite was further modified by polyethylene glycol, and the modified composite had good dispersion and stability in PBS buffer solution. Poly (ethylene glycol) functionalized iron trioxide nanocomposites were prepared by mercaptan click-chemical method. The samples were characterized by XRD,TEM,FT-IR,UV-vis,Raman et al. The preparation method is mild, easy to operate and easy to deal with. The prepared product has good stability and dispersion in water or PBS buffer solution. Polyethyleneimine-functionalized iron trioxide nanoparticles cluster was prepared by using 3.4-dihydroxyphenylpropionic acid as the intermediate. The samples were characterized by TEM,FT-IR and Zeta potential and their magnetic properties were tested. The method is simple, the reaction conditions are mild, the preparation time is short, the prepared product has good dispersion and stability in water and PBS solution. The relaxation behavior of dopamine-functionalized iron trioxide nanoparticles and graphene oxide nanoparticles were investigated. The results show that the longitudinal relaxation time of dopamine functionalized iron trioxide nanoparticles decreases with the increase of iron ion concentration and the R1 value of the aqueous solution is 0. 65 m MS-1, at 10 Mt. The time domain signal in water at 10 m T can increase with the increase of polarization time at a certain time, and the reciprocal of spin-lattice relaxation time is 3.05S-1 by fitting formula. The values of r _ 1 and r _ 2 of the larger particle size of graphene oxide nanoparticles were higher than those of the smaller particles.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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