快速配体交换法制备水溶性磁性Fe3O4纳米粒子

Synthesis of Water-Soluble Magnetic Fe3O4 Nanoparticles through Fast Ligand-Exchange Method

摘要:

为了获得水溶性Fe3O4纳米粒子，本文以聚乙二醇（PEG）磷酸酯为亲水性配体，在甲苯/四氢呋喃/水三元混合溶剂体系下通过快速配体交换法将油酸包覆的油溶性磁性Fe3O4纳米粒子转变成聚乙二醇磷酸酯包覆的水溶性Fe3O4纳米粒子。考察了四氢呋喃等溶剂在实现快速配体交换中所起到的作用。利用透射电子显微镜(TEM)、动态光散射( DLS)、X射线粉末衍射仪（XRD）、傅立叶红外光谱仪（FTIR）、振动样品磁强计（VSM）对磁性Fe3O4纳米粒子进行了分析表征。结果表明：四氢呋喃可以促进PEG磷酸酯与Fe3O4纳米粒子表面的有效接触并使得油酸分子从纳米粒子表面快速地脱附下来，此外，还消除了配体交换过程中出现的乳化效应。四氢呋喃的应用实现了快速配交换法制备水溶性PEG磷酸酯包覆的磁性纳米粒子。

Abstract:

In order to obtain water-soluble Fe3O4 nanoparticles (NPs), fast ligand exchange method was applied to make hydrophobic oleic acid coated Fe3O4 NPs turn into water-soluble PEG [PEG = poly(ethylene glycol)] phosphate coated Fe3O4 NPs using PEG phosphate as the hydrophilic ligand in toluene/tetrahydrofuran (THF)/water ternary mixed solvent system. The effect of THF on the ligand-exchange rate was studied. The NPs were characterized by means of TEM, DLS, XRD, FTIR and VSM, respectively. Results showed that THF solvent could promote effective contact of PEG phosphate molecules with the surface of Fe3O4 NPs, and make oleic acid molecules rapidly desorbe from the surface of the NPs, in addition, they eliminated the emulsification during the ligand exchange process. A rapid ligand exchange method used to prepare the water-soluble PEG phosphate coated Fe3O4 NPs was achieved by using of THF solvent.