P(St-co-AA)与Fe3O4纳米粒自组装制备高分子磁微球

Self-assembling Magnetic Microspheres by P(St-co-AA) and Fe_3O_4 Nanoparticles

用微乳液聚合法制备了粒径均匀的聚苯乙烯-丙烯酸高分子微球P(St-co-AA),与共沉淀法所制纳米Fe_3O_4通过静电作用,使两种微球自组装成高磁含量的磁性微球[Fe_3O_4/P(St-co-AA)].采用XRD,TEM、SEM、IR等对样品进行表征,采用VSM对样品进行磁性能测试.结果表明P(St-co-AA)平均粒径约为70nm,表面含有羧基;所得磁粉为Fe_3O_4单相,平均粒径约为10nm.磁性能测试表明,当外加磁场为1.5×10~6/π(A/m)时,磁化强度达到饱和,饱和磁化强度为69A·m^2·kg^(-1);自组装所制高分子磁性微球为球形,平均粒径约800nm,磁粉含量为15.8%.研究表明,pH值、搅拌等对复合磁性微球的形成有重要影响.

Uniform P（St-co-AA） microspheres were prepared by microemulsion polymerization. The Fe3O4/P（St-co-AA） microspheres with a high magnetic content were prepared by electrostatic self- assembly using P（St-co-AA） microspheres with Fe3O4 nanoparticles synthesized by co-precipitation. The effects of pH, stirring on the preparation of Fe3O4/P （St-co-AA） were investigated. All samples were characterized by transmission electron microscope （TEM）, scanning electron microscope（SEM）, X-ray diffraction（XRD）, FTIR spectroscope. The magnetic property of the obtained magnetic powder with Fe3O4 single phase was tested by VSM. The results indicate that the average sizes of polymer microspheres P（St-co-AA） with carboxyl and the magnetic powders Fe3O4 are 70nm and 10nm, respectively. Magnetic property measurement shows that the saturated magnetization of the magnetic powders is 69A.m^2.kg^-1 when the applied field is up to 1.5×10^6/u（A/m） at room temperature. The assembled Fe3O4/P（St-co-AA） with an average size of 800nm is spherical and the content of magnetic powders is 15.8%.