纳米Fe_3O_4磁性粒子的制备及吸附性能研究

采用共沉淀法制备了纳米Fe3O4磁性粒子。应用透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X-射线衍射仪(XRD)和振动样品磁强计(VSM)等对纳米磁性粒子的粒径、结构、形貌、磁性能进行了表征,进行了磁分离沉降性能和腐殖酸吸附去除实验研究。结果表明:在未添加任何分散剂的条件下,制得的纳米Fe3O4磁性粒子主要呈球状,平均粒径约11 nm,为典型的反尖晶石结构;饱和磁化强度、矫顽力和剩余磁化强度分别为73.10 emu/g、159.2 A/m和0.41 emu/g;磁分离沉降速度为重力场的50倍;纳米Fe3O4磁性粒子对腐殖酸的吸附符合Langmuir型吸附等温线。

Study on preparation of Fe3O4 magnetic nanoparticles and their adsorption properties

Fe_3O_4 magnetic nanoparticles were prepared by coprecipitation method. The particle size, structure, morphology and magnetic property of Fe_3O_4 nanoparticles were characterized by transmission electron microscopy (TEM)、scanning electron microscopy (SEM)、X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). Settlement performance of magnetic separation and removal of humic acid adsorption tests were studied. The results showed that: under the condition of no dispersant added, Fe_3O_4 magnetic nanoparticles obtained had mainly spherical morphology, the average particle size was about 11 nm, belonging to typical anti-spinel structure. Saturation magnetization, coercivity and residual magnetization of Fe_3O_4 magnetic nanoparticles were 73.10 emu/g,159.2 A/m and 0.41 emu/g,respectively. The settling velocity of magnetic separation for the gravity was up to 50 times. The adsorption of Fe_3O_4 magnetic nanoparticles on humic acid was consistent with the Langmuir-type adsorption isotherm.