超声乳化法制备纳米Fe3O4磁性颗粒及壳聚糖表面改性

采用超声乳化法制备纳米Fe₃O₄磁性颗粒,以壳聚糖作为表面活性剂,制备具有生物亲和性的水基Fe₃O₄磁流体.研究了Fe²⁺/Fe³⁺摩尔比、超声时间和表面活性剂用量对磁流体性能的影响.结果表明:当Fe²⁺/Fe³⁺摩尔比为1:1.5,滴加氨水时反应温度为70℃时,可制备理想纳米Fe₃O₄磁性颗粒;超声时间为7.5min左右,质量分数1%的壳聚糖溶液体积占FeO溶液总体积的50%时,有利于壳聚糖分子的包覆,使磁流体具有较高的比饱和磁化强度及稳定性.

Preparation of Fe3O4 magnetic nanoparticles by ultrasonic emulsification and research of magnetic fluids with chitosan modification

Fe₃O₄ magnetic nanoparticles were prepared by means of ultrasonic emulsification and then the Fe₃O₄ magnetic fluid was made by dispersing these particles into water with chitosan as surfactants.The influences of the molar ratio of Fe²⁺ to Fe³⁺,ultrasonic time and the amount of chitosan on the magnetic properties of the magnetic fluid were investigated.The results show that ideal Fe₃O₄ magnetic nanoparticles can be obtained under the condition that the molar ratio of Fe²⁺ to Fe³⁺ is 1:1.5 and the reaction temperature is 70℃ when dropping ammonia.The prepared magnetic fluid has high specific saturation magnetization and stability when the volume of the 1% chitosan solution is 50% as large as the total volume of the mixed Fe₃O₄ solution and the ultrasonic time after dropping chitosan is 7.5 min,which are in favor of coating the magnetic particles with chitosan.