种子溶胀聚合制备单分散聚苯乙烯磁性微球

Preparation of Monodisperse Magnetic Polystyrene Microspheres by Seed Swelling Polymerization

以无皂乳液聚合法制备的粒径约为500 nm的聚苯乙烯(PS)微球为种子,在苯乙烯分散的Fe_3O_4磁性溶胶存在下,通过种子溶胀法制备了单分散PS磁性微球。通过SEM,TEM,XRD,TG等表征手段研究了PS磁性微球的形貌、粒径、组成及其热稳定性,并采用振动样品磁强计测定了PS磁性微球的磁响应性。研究结果表明,PS磁性微球的平均粒径约为900 nm,具有良好的均一性、单分散性、热稳定性和超顺磁性,室温下没有发现剩磁和磁矫顽力,饱和磁化强度约为12 emu/g,可通过外加磁场有效分离,具有优异的磁响应性。

Monodisperse magnetic polystyrene（PS） microspheres were prepared via seed swelling polymerization in the presence of magnetic Fe3O4 sol-gel dispersed in styrene. The seeds were PS microspheres with an average diameter of 500 nm prepared by soap-free emulsion polymerization. The morphology, particle size, composition, thermal stability and magnetic response of the magnetic PS microspheres were investigated by means of SEM, TEM, XRD, TG and vibrating sample magnetometer. The results showed that the PS microspheres exhibited uniform particle size distribution with the average particle size of about 900 nm, good monodispersity, high thermal stability and superparamagnetism. There were no remanence and coercivity at ambient temperature. The saturation magnetization of the PS microspheres reached 12 emu/g. The PS microspheres can be separated by magnetic field effectively.