聚乙二醇包覆纳米Fe_3O_4颗粒的制备及表征

Preparation and Characterization of PEG-coated Fe_3O_4 Nanoparticles

采用化学共沉淀法制备了聚乙二醇(PEG4000)包覆的纳米Fe3O4颗粒,然后分散于水中制成磁性液体,研究了PEG用量对磁性液体稳定性的影响。粒度测试和形貌分析表明,PEG包覆的纳米Fe3O4颗粒平均粒径为30nm,包覆层厚度约5～10nm,粒径分布较窄。红外光谱分析表明,PEG与纳米Fe3O4主要以氢键结合,结合差热和电镜分析,认为颗粒的分散作用主要是空间位阻作用,PEG用量为15wt%的纳米Fe3O4颗粒的PEG包覆量约为9wt%。吸光度测试表明,随着聚乙二醇用量的增加,悬浮液的稳定性提高,用量15wt%时,悬浮液分散稳定性最好,包覆样的饱和磁化强度为57A·m2/kg,具有良好的超顺磁性。

PEG-coated Fe3O4 nanoparticles were prepared by co-precipitation method, and the effect of PEG content on the magnetic fluid stability was investigated. The analysis showed that the Fe3O4 nanoparticles were prepared with an average particle size of about 30nm, PEG-coated thickness of about 5 to 10nm. IR results indicated that the Fe3O4 nanopartieles were coated by hydrogen bond. According to both the TG and TEM examination, the dispersal of particles was mainly a result of steric hindrance, and the proportion of coated PEG was about 9%. The absorbance test results revealed that the stability of fluids increases with increasing PEG content. For the fluid coated with 15% PEG; the dispersion stability of fluids was the best of all. The coated particle sample has a saturation magnetization of 57A·m^2/kg and exhibits good superparamagnetism.