摘要
通过滴加氨水控制Fe(Ⅱ)与Fe(Ⅲ)盐混合溶液的pH值,经共沉淀法制得了Fe3O4纳米颗粒,其平均粒径约为13nm。进而用一定量的油酸钠对其原位改性,得到了表面呈疏水性的油基Fe3O4纳米颗粒。在Fe3O4纳米颗粒和二乙烯苯(DVB)存在下,以聚乙烯吡咯烷酮(PVP)为稳定剂,乙醇/水的混合体系为反应介质,由偶氮二异丁腈(AIBN)引发甲基丙烯酸甲酯(MMA)和丙烯酸(AA)进行分散共聚,制得了PAA-PMMA交联型磁性复合微球,核内富含Fe3O4纳米颗粒,其含量可分别调整在42%~71%(质量分数)之间,改变聚合反应条件可将复合微球的粒径控制在100nm^2μm的范围内。研究发现Fe3O4纳米颗粒被PAA-PMMA包覆后,可明显延长其在盐酸中的稳定性。在外加磁场作用下该复合微球能实现快速的分离。
Magnetic nanoparticles were synthesized by in-situ precipitation method through dropwise adding aqueous solution of ammonia to mixed solution of Fe ( Ⅱ ) and Fe ( Ⅲ ) salts. The average diameter of the magnetic nanoparticles is 13nm based on the observation of transmission electron microscopy. The surface of Fe3O4 nanoparticles was modified by using a certain amount of sodium oleate under in-situ processing, to obtain hydrophobic surface of the oil-based Fe3O4 nanoparticles. Crosslinked magnetic composite microspheres with poly (crylic acid)-co-poly(methyl methacrylate) (PAA-PMMA) as shell and Fe3O4 as core were obtained by dispersion copolymerization initiated with 2,2'-azobisisobutyronitrile (AIBN) in ethanol/water mixed solvent containing poly (vinylpyrrolidone) (PVP) as stabilizer in the presence of Fe3O4 nanoparticles and divinylbenzene (DVB). The crosslinked microspheres contained 42wt%-71wt% of Fe3O4 through TGA analysis. The average size of the microspheres can be controlled in the range of 100nm-2μm by changing the polymerization conditions. It was found that the stability of the Fe3O4 nanoparticles was prolonged in HCl solution when it packed with PAA-PMMA. The magnetic composite microspheres were separated quickly under the external magnetic field.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2008年第11期1809-1812,共4页
Journal of Functional Materials
基金
国家自然科学基金资助项目(20671043)
江苏高等学校科技创新团队资助项目(苏教科[2007]5号)
关键词
Fe3O4磁性纳米颗粒
甲基丙烯酸甲酯
分散共聚
交联磁性微球
Fe3O4 magnetic nanoparticle
methyl methacrylate
dispersion copolymerization
crosslinked magnetic microsvhere