葡聚糖包覆纳米Fe3O4颗粒的研究

采用化学共沉淀法制备了葡聚糖包覆的纳米Fe3O4颗粒,平均粒径为6nm,包覆层厚度约为3～5nm,纳米Fe3O4粒径分布较窄.红外光谱分析可知,葡聚糖与纳米Fe3O4主要以氢键结合,结合Zeta电位和热重分析,分散作用主要是空间位阻作用,葡聚糖的包覆量约为10%.吸光度测试表明,随着葡聚糖用量的增加,悬浮液的稳定性提高.用量为25%时,悬浮液在室温下静止1周,无分层现象.包覆样的饱和磁化强度为60emu/g,具有良好的超顺磁性.

Study on Dextran-coated Fe3O4 Nanoparticles

Magnetic nanoparticles are prepared by co-precipitation method using dextran as coating agent,with the average size of particles about 6nm,thickness of dextran-coated about 3nm to 5nm.After coating,the Fe3O4 particle size distribution is narrow.IR results indicate that the Fe3O4 nanoparticles are coated by hydrogen bond.With the zeta potential and TG,the dispersal of particles is obtained due to steric hindrance,and the proportion of coated dextran is about 10 %.The ab-sorbance is observed to study the magnetic response properties.The results indicate that the stability of fluids is enhanced with the increase of dextran.As for the fluid coated with 25% dextran,no stratification appeares after placing at room temperature for a week.The result of VSM supports that the saturated magnetization intensity of naked particles is 60emu/gwith good superparamagnetism.