相反转工艺制备Fe_3O_4/P(St-BA)复合微球的研究

Research of Fe_3O_4/P(St-BA)composite microspheres via phase inversion process

采用共沉淀法制备了油酸修饰的Fe3O4纳米粒子,并采用相反转工艺制备了Fe3O4/P(St-BA)复合微球。用透射电镜(TEM)和热失重(TGA)方法表征了Fe3O4纳米粒子、Fe3O4/P(St-BA)复合微球的形貌和Fe3O4含量。TEM显示大部分Fe3O4粒子被包覆在复合微球内部,同时有部分Fe3O4粒子嵌在微球表面。研究表明:Fe3O4/P(St-BA)复合微球具有良好的磁响应性,油酸量为0.4g修饰的Fe3O4粒子在混合单体中分散效果好。粒度测试结果显示转相水体系中聚乙烯醇和十二烷基硫酸钠复配制备的微球粒径较小且分布较窄;转相过程提高转速微球平均粒径变小,粒度分布变窄。

Oleic acid modified Fe3O4 nanoparticles were synthesized by co-precipitation method,then Fe3O4/P（StBA）composite microspheres were prepared by phase inversion process.Transmission electron microscopy（TEM）and thermo-gravimetric analysis（TGA）were used to characterize the morphology of Fe3O4 nanoparticles and Fe3O4/P（St-BA）microspheres and the content of Fe3O4,respectively.TEM indicated that the majority of Fe3O4 nanoparticles were located on Fe3O4/P（St-BA）microspheres,meanwhile there were part of Fe3O4 nanoparticles embedded in the surface of the microspheres.Results showed that the microspheres had excellent magnetic response,Fe3O4 nanoparticles modified by 0.4g oleic acid had better dispersant effect in mixed monomers of styrene and butyl acrylate.Malvern laser particle size analyzer illustrated that the microspheres prepared by polyvinyl alcohol together with sodium dodecyl sulphate in inverse phase water had smaller particle size and narrower distribution.Increasing stirring speed within certain range during phase inversion decreased the average particle size and size distribution of the microspheres.