酸碱度对纳米Fe_3O_4磁性流体性能的影响

The influence of pH on the properties of kerosene-based magnetic fluid

采用化学共沉淀法制备纳米Fe3O4磁性颗粒,并用油酸钠对其进行包覆改性,以煤油为基液制备出煤油基Fe3O4磁流体。对比分析了pH值=5和10.5条件下油酸钠包覆的Fe3O4磁性颗粒的性能差异,得出油酸钠在pH值=5时可以更好地包覆在Fe3O4磁性颗粒表面,其饱和磁化强度为58.0A·m2/kg,在此基础上制备出的磁流体的饱和磁化强度为20.2A·m2/kg,并且Fe3O4磁性颗粒分散较均匀。而油酸钠在pH值=10.5时包覆的Fe3O4磁性颗粒,其饱和磁化强度虽然高一些(67.8A·m2/kg),但制备出的磁流体稳定性较差,出现较为明显的沉降现象。

In this paper, Fe3O4 magnezic nanoparzicles were prepared by clnemical co precipizazion naezlnod and surface modification by sodium oleate were introduced. The kerosene based Fe3O4 magnetic fluid was prepared by using kerosene as carrier liquid. Compared with differences of Fe3O4 magnetic particles coated by sodium ole ate in the conditions of pH 5 and 10.5. It showed that the nanoparticles were coated successfully by sodium oleate. The saturation magnetization of Fe3O4 magnetic nanoparticles was ,58. 0 A · m2/kg, the saturation magnetization of magnetic fluid prepared was 20.2 A · m2/kg, and Fe3O4 particles were well dispersed. AI though in the case of pH 10.5, Fe3O4 magnetic particles coated by sodium oleate had a higher saturation mag netization （67.8 A · m2/kg）, but the magnetic fluid was less stable and had a obvious settlement phenomenon.