油酸表面改性对Fe_3O_4纳米粒子结构和分散性的影响

Effect of surface modification by oleic acid on the microstructure and dispersibility of Fe_3O_4 nanoparticles

以NH3.H2O为沉淀剂,利用化学共沉淀法制备粒径分布均匀的超顺磁性纳米Fe3O4粒子。针对Fe3O4纳米粒子易团聚的现象,采用有机化合物油酸对其进行表面改性。采用X射线粉末衍射仪(XRD)、透射电子显微镜(TEM)、傅里叶红外光谱仪(FT-IR)及振动样品磁强计(VSM)等手段对Fe3O4纳米粒子进行结构与性能表征。结果表明,所得Fe3O4纳米粒子平均粒径为20nm、粒径分布窄、饱和磁化强度为70.29 A.m2/kg,矫顽力为零,具有超顺磁性。利用油酸进行表面改性可有效降低Fe3O4纳米粒子的团聚,使其分散度得到提高。

Uniform and superparamagnetic Fe3O4 nanoparticles were synthesized by chemical co-precipitation successfully using NH3＇H20 as precipitating agent. In order to reduce the aggregation of Fe3O4 nanoparticles, organic additives of oleic acid was used as surface modification agent coating onto the surface of Fe3O4 nanoparticles. The microstructure and properties of both uncoated and oleic acid coated Fe3O4 nanoparticles were characterized by XRD, TEM, FT-IR and VSM, respectively. As a result, the oleic acid coated Fe3O4 super-paramagnetic nanoparticles were prepared with an average partical size of 20 nm, narrow size distribution and saturation magnetization of 70.29 A·m^2/kg. And it can get a conclusion that the surface modification of Fe3O4 by oleic acid can effectively decrease agglomeration ofFe3O4 nanoparticles, improving their dispersibility.