Fe_3O_4/聚乙烯亚胺/金磁性复合材料的光化学制备与表征

Photochemical preparation and characterization of Fe_3O_4/poly ethyleneimine/Au nanocomposites

以沉淀法合成的Fe3O4/聚乙烯亚胺纳米粒子为磁核,采用光化学法在氯金酸水溶液中制备了Fe3O4/聚乙烯亚胺/纳米金磁性复合材料,并用X射线衍射仪、透射电子显微镜和振动样品磁强计表征了产物。结果表明:制备的Fe3O4/聚乙烯亚胺磁粒的平均尺寸为6.8 nm,呈现准超顺磁性,饱和磁化强度为37.4 A.m2.kg-1。Fe3O4/聚乙烯亚胺/纳米金磁性复合材料呈不规则团状,尺寸介于13-23 nm的金粒子分布在由很多Fe3O4/PEI聚集而成的亚微米团状体表面;该复合材料呈现准超顺磁性,具有较高的饱和磁化强度(36.9 A.m2.kg-1)和良好的磁响应性,有望用于生物分离、生物传感器等领域。

Core-shell magnetite/polyethyleneimine nanoparticles （Fe3O4/PEI） were synthesized by a precipita- tion method using polyethyleneimine （PEI） as a stabilizer. Au colloids-modified magnetic nanocomposites （Fe3O4/PEI/Au） were then prepared by a photochemical method in a HAuCI4 aqueous solution, using Fe3O4/PEI as the magnetic core. The samples were characterized by transmission electron microscope, X-ray diffraction and vi- brating sample magnetometer. The results showed that Fe3O4/PEI nanoparticles with a mean size of 6.8 nm were qua- si-superparamagnetic and the saturated magnetization is at about 37.4 A.m2.kg-1. The obtained Fe3O4/PEI/Au is irreg- ular in shape, composed of a sub-micron aggregate of Fe3O4/PEI nanoparticles and some Au colloids with sizes rang- ing from 13 nm to 23 nm. Additionally, the quasi-superparamagnetic nanocomposites are magnetically susceptible and the saturated magnetization reaches 36.9 A.m2-kg-1. Therefore, Fe3O4/PEI/Au nanoparticles can be used in many areas including bioseparation and biosensors.