纳米Fe3O4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11nm，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73．10emu／g、159．2A／m和0．41emu／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

Fe3O4 magnetic nanoparticles were prepared by coprecipitation method. The particle size, structure,morphology and magnetic property of Fe3O4 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,Fe3O4 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 Fe3O4 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 Fe304 magnetic nanopartieles on humic acid was consistent with the Langmuir-type adsorption isotherm.