高稳定性水基γ-Fe_2O_3超顺磁纳米颗粒制备及其表面改性研究

Synthesis and surface functionalization of highly stable water-based colloidal superparamagnetic γ-Fe_2O_3 nanoparticles

采用共沉淀法,以氯化铁(FeCl_3·6H_2O)和氯化亚铁(FeCl_2·4H_2O)为原料,以氨水为沉淀剂制备出尺寸为10 nm左右,粒径分布均一的γ-Fe_2O_3超顺磁颗粒.同时采用不同相对分子质量聚丙烯酸对该颗粒进行表面包覆改性.利用X射线衍射仪(XRD)、振动样品磁强计(VSM)、透射电子显微镜(TEM)以及动态光散射技术(DLS)对产物的晶体结构、磁性能及形貌等进行表征,并利用DLS研究了纳米颗粒在盐溶液及细胞培养液中的尺寸变化.结果表明,包覆后纳米颗粒表面具有的有机表层不仅提供了游离的羧基生物官能团,并且进一步优化增强了颗粒在水基胶体环境中的稳定性,其在较高浓度盐溶液及细胞培养液中均保持超长时间的独立稳定,是优良的生物医药功能材料前体.

In this work,we have synthesized γ-Fe2O3 superparamagnetic nanoparticles by using co-precipi-tation method.The phase structures, magnetic property and morphology of the resulted bare particles have beencharacterized by X-ray diffraction （XRD）, Vibrating Sample Magnetometer （VSM）, Transmission Electron Mi-croscopy （TEM） and Dynamic Light Scattering （DLS）.The size of resulted bare particle is about 10 nm. After-wards,we have coated the bare nanopartieles by using polyaerylie acid with different molecular weight.The poly-mer coated nanoparticles have been characterized by XRD,TEM and DLS as well.Furthermore, the colloidal sta-bility of coated nanopartieles in concentrated salt （NH4C1） solution and cell-culture medium （high glucose ）have been monitored by using DLS.The DLS results show that coated nanoparticles present remarkable colloidalstability, which is an excellent precursor for further biomedical application.