Fe_3O_4/PSF磁性复合超滤膜的制备、表征及应用

Preparation,characterization and utilization of Fe_3O_4/PSF magnetic composite ultrafiltration membrane

以FeCl2为还原剂,采用模板和化学镀相结合的方法制备Fe3O4/PSF磁性复合超滤膜,对所制膜的表面形貌、内部结构和孔径大小等性质进行表征,随后进行溶菌酶截留实验,并对截留机理进行分析.扫描电镜(SEM)观察可知,粒子主要沉积在复合膜的孔道中;X射线衍射(XRD)分析可知,沉积粒子主要为Fe3O4,粒径为6.99 nm;液液界面法测得,复合超滤膜的平均孔径从无磁场下的9.36 nm减小到0.8 T磁场下的8.54 nm;在外加磁场下,复合超滤膜对不带电的溶菌酶截留率增大,对带电的溶菌酶截留率减小.经过分析认为,复合超滤膜在磁场下的超滤机理,主要是磁场诱导效应和磁致伸缩效应,并且前者的作用大于后者.

On the basis of template and electroless methods, Fe3O4/PSF magnetic comyasite ultrafiltration mem- brane was prepared with FeCl2 as reduced agent. The properties of the membrane prepared, such as surface mor- phology, internal structure and pore size distribution,were characterized. Then the lysozyme rejection test was performed, and the rejection mechanism was analyzed preliminarily. SEM show that most particles deposite in the pore of the membrane. XRD analysis indicates that particles deposited in the pore are mainly Fe3O4, and the particle size calculated from XRD results is about 6.99 nm. The results measured by Liquid - liquid displacement method show that the average pore size declines from 9.36 nm without magnetic field to 8.54 nm in magnetic field with the intensity of 0.8 T. The rejection to uncharged lysozyme of composite ultrafiltration membrane rose in magnetic field, while the rejection to charged lysozyme declined in magnetic field. After analysis, we re- alized that the rejection mechanism of composite ultrafiltration membrane in magnetic field was the magnetoin- ductive and magnetostrictive effect, and the former effect is greater than the latter.