纳米Fe_3O_4包覆结构及其磁流体稳定性

Covering structure and stability of nanosized Fe_3O_4 magnetic liquid

采用化学共沉淀法制备纳米Fe3O4粉体,通过机械球磨的方法研究阴离子表面活性剂十二烷基苯磺酸纳(SDBS)的用量对纳米Fe3O4的包覆结构及其磁流体分散效果的影响。对制得的样品经过XRD,HRTEM,FT-IR和XPS等进行表征。在50 mL水溶液中,当纳米Fe3O4质量为10 g,pH为4.5和球磨时间为5 h时,SDBS最佳用量为0.8 g;SDBS以化学和物理吸附在尖晶石结构的Fe3O4纳米颗粒表面,形成了Fe-O-S化学键使得纳米颗粒表面的包覆结构很难被打破,制得的磁流体具有较强的稳定性。

Fe3O4 nanoparticles were prepared with Chemical co-precipitation method.The covering structure and stability of nanosized Fe3O4 magnetic liquid effected by the dosage of sodium dodecyl benzene sulfonate（SDBS） were investigated with ball milling method.The samples were measured by X-ray diffraction（XRD）,high-resolution retransmission electron microscopy（HRTEM）,Fourier transform infrared spectrometry（FT-IR） and X-ray photoelectron spectroscopy（XPS）.The results show that when the mass of Fe3O4 is 10 g in 50 mL water,pH is 4.5 and the ball milling time is 5 h,the better dosage of SDBS is 0.8 g.SDBS is adsorbed on the surface of Fe3O4 nanoparticles with spinel structure by multi-layer chemisorption and physisorption.And the Fe-O-S chemical bond makes the encasing structure difficult to be broken,and the magnetic liquid is stable.