基于超顺磁纳米颗粒的磁性纳米线研究

发布时间：2018-08-28 10:18

【摘要】：一维磁性纳米线由于在细胞操作、微流体以及微观力学等方面的应用潜力,一直备受关注。为此,人们不断探索简单有效的纳米线组装方法并试图研究其组装机理。在本研究中,主要采用超顺磁纳米颗粒与常用的同性聚电解质聚合物作为组装单元,通过自然界常见的静电相互作用组装制备一维磁性纳米线,并通过改变γ-Fe2O3超顺磁纳米颗粒与阳离子聚电解质聚合物的量控制溶液电荷比值Z、透析温度T等参数控制纳米线结构与形貌,研究其组装机理。本文通过共沉淀法制备的γ-Fe2O3纳米颗粒,采用XRD、VSM、TEM等分析测试手段对所制备样品进行表征,结果表明该样品具有典型的超顺磁性,颗粒粒径较为均一,多分散性较小。通过聚丙烯酸对其表面包裹改性后,DLS结果表明其包裹层厚度约5nm,且包裹后纳米颗粒在水基环境、高浓度盐环境、细胞培养液环境中具有更优良的胶体稳定性。包裹改性后的γ-Fe2O3超顺磁纳米颗粒表面带有大量的游离羧基官能团,为其进一步的生物功能化做好了准备,是理想的生物医药材料前驱体,在核磁共振造影剂、靶向给药、热疗剂等方面具有广阔的应用前景。通过静电络合法自组装制备出各向异性一维磁性纳米线结构。所制备纳米线结构呈一维准直结构。纳米线结构受组装过程中温度、电荷比值等因素影响。结果表明温度越高,所制备纳米线长度越长,温度越低,纳米线长度较小;电荷比值Z=7时,所制备纳米线长度为18.62um,当Z=0.3时,纳米线长度为75.97um,当正负电荷总数基本相等,即Z=1时,样品团聚较明显,未形成明显一维结构。另外,本文还探讨了纳米线的组装机理,为纳米线组装制备提供了新的方法。
[Abstract]:One-dimensional magnetic nanowires have attracted much attention due to their potential applications in cell manipulation, microfluid and micromechanics. Therefore, simple and effective assembly methods of nanowires have been explored and the assembly mechanism of nanowires has been studied. In this study, superparamagnetic nanoparticles and common polyelectrolyte polymers were used as assembly units to prepare one-dimensional magnetic nanowires by electrostatic interaction. The structure and morphology of the nanowires were studied by changing the charge ratio of 纬 -Fe _ 2O _ 3 superparamagnetic nanoparticles to cationic polyelectrolyte polymer Z and dialysis temperature T. In this paper, 纬 -Fe _ 2O _ 3 nanoparticles prepared by co-precipitation method were characterized by XRD,VSM,TEM and other analytical methods. The results showed that the sample had typical superparamagnetism, uniform particle size and low polydispersity. The results of DLS show that the coating layer thickness is about 5 nm, and the colloidal stability of the coated nanoparticles is better in water environment, high concentration salt environment and cell culture medium. The surface of the modified 纬 -Fe _ 2O _ 3 superparamagnetic nanoparticles has a large number of free carboxyl functional groups, which is prepared for its further biological functionalization. It is an ideal biomedical precursor, which can be used as a contrast agent for nuclear magnetic resonance (NMR) and as a target drug. Hyperthermia has a broad application prospect. Anisotropic one-dimensional magnetic nanowires were fabricated by electrostatic complexing method. The nanowire structure is one-dimensional collimation structure. The nanowire structure is affected by temperature, charge ratio and other factors during the assembly process. The results show that the length of nanowires is longer, the temperature is lower and the length of nanowires is smaller with the increase of temperature, and the length of nanowires is 18.62 um. when the charge ratio is 7, the length of nanowires is 75.97 um.When the charge ratio is 0.3, the length of nanowires is 75.97 um.When the total number of positive and negative charges is almost equal, that is, Z = 1, The agglomeration of the sample was obvious and no obvious one-dimensional structure was formed. In addition, the assembly mechanism of nanowires is discussed, which provides a new method for the fabrication of nanowires.
【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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