空心Fe3O4纳米微球的制备及超顺磁性  

Synthesis and superparamagnetism of Fe_3O_4 hollow nano-microspheres

作　　者：李文宇[1] 霍格 黄岩[3] 董丽娟[1] 卢学刚[3] Li Wen-Yu;Huo Ge;Huang Yan;Dong Li-Juan;Lu Xue-Gang(Institute of Solid State Physics,Shanxi Datong University,Datong 037009,China;MOE Key Laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter,School of Science,Xi＇an Jiaotong University,Xi＇an 710049,China;College of Material Science and Engineering,Shenzhen University,Shenzhen 518061,China)

机构地区：[1]山西大同大学固体物理研究所,大同037009 [2]深圳大学材料学院,深圳518061 [3]西安交通大学理学院物质非平衡合成与调控教育部重点实验室,西安710049

出　　处：《物理学报》2018年第17期247-253,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号：51172178)资助的课题

摘　　要：采用水热控制合成法,以六水三氯化铁、柠檬酸三钠和尿素为原料,聚丙烯酰胺为稳定剂, 200?C下反应12 h制备得到了超顺磁性空心Fe_3O_4纳米微球.通过X射线衍射仪、扫描电子显微镜、透射电子显微镜对样品的结构和形貌进行表征,并采用振动样品磁强计测试了样品的磁性能.结果表明:所得样品为具有尖晶石结构的Fe_3O_4纳米微球,尺寸为160 nm左右,呈分等级结构,即整个微球由粒径约18 nm的初级晶粒自组装堆叠而成;室温下表现为典型的超顺磁性,且饱和磁化强度为73.3 emu/g (1 emu/g=1 A·m^2/kg),这种高饱和磁化强度可以由其初级晶粒晶化程度高且粒径较大以及这种特殊的二次自组装结构进行解释.这种Fe_3O_4纳米微球为疏松多孔的空心球状结构,具有粒径分布均匀、分散性良好和超顺磁性的特点,在药物靶向输运和肿瘤热疗中有潜在的应用.Fe3O4 nanomaterials have received great attention due to their many applications in tumor diagnosis and tumor heat therapy based on their good biocompatibility, magnetic targeting ability and superparamagnetic properties to avoid magnetic reunion in the process of magnetic targeting. Most of superparamagnetic nanoparticles obtained by traditional methods exhibit lower saturation magnetization（MS）, because of their small particle sizes. Enlarging the particle size is favorable to increase the MS of magnetic particles. However, the superparamagnetism of the particle could be lost with the increase of particle size. This is not favorable to the targeting delivery of magnetic particles. For this purpose, in this paper, novel Fe3O4 nano-microspheres with mesoporous hollow structure are successfully synthesized by a facile hydrothermal method from the FeCl36H2 O, sodium citrate, urea, and polyacrylamide as additive, the reaction temperature is 200？C and reaction time is 12 h. The crystal structure and purity of the resulting products are examined by powder X-ray diffraction（XRD）. The morphologies of the products are studied by using scanning electron microscopy（SEM） and transmission electron microscopic（TEM）. The magnetic properties of Fe3O4 nano-microspheres are evaluated with a vibrating sample magnetometer. The morphology evolution process and possible formation mechanism of Fe3O4 nano-microspheres are investigated. The findings are as follows： all XRD peaks of the hollow Fe3O4 nano-microspheres could be assigned to the spinel-type Fe3O4. The SEM and TEM images reveal that the products are mesoporous hollow Fe3O4 nano-microspheres and possess hierarchical structure, in which large microspheres（160 nm） are self-assembled by smaller Fe3O4 initial crystals（18 nm）. It is found that the synthetic time of Fe3O4 nano-microspheres is considerable for the formation of the Fe3O4 hierarchical structure, and that the dispersion and sphericity of Fe3O4 nano-microspheres are the best when reaction time

关 键 词：水热法 空心Fe3O4纳米微球 分等级结构 超顺磁性 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TQ138.11[化学工程—无机化工]