树形高分子增强的高分子磁性颗粒的制备与表征

利用化学共沉淀法制备Fe3O4磁性纳米粒子;悬浮聚合的方法制备带有酰胺基的聚苯乙烯-丙烯酰胺磁性颗粒(NMP);发散法制备聚酰胺胺树形高分子(PAMAM)并与酰胺修饰聚苯乙烯磁性颗粒结合,得到树形高分子增强的磁性微粒。并对NMP和PAMAM-NMP的颗粒基质晶体结构、饱和磁化强度、表面官能团和微观结构以及各元素的百分含量进行表征。结果显示,Fe3O4磁核晶形完整,平均粒径为9 nm;PAMAM-NMP的红外图谱在3478 cm-1和3 300 cm-1处有吸收峰,证明存在胺基;经PAMAM增强后氮元素百分含量由0.225%增加到0.992%,证明PAMAM为NMP提供了更多的活性基团;在有无磁场存在时的沉淀时间分别为16 h和2112 h,证明PAMAM-NMP有良好的磁响应性和悬浮性。

Preparation and characterization of macromolecular magnetic particle enhanced by PAMAM dendrimers

Fe3O4 nano-particles were prepared by chemical precipitation method.PSt-acrylamide/Fe3O4 magnetic particles were synthesized by suspension method.PAMAM was prepared and then was used to react with the magnetic particles.Magnetic particles enhanced by dendrimers were successfully prepared.Many methods were used to characterize the crystal structure,saturation magnetization,functional group,micro-structure and elemental percentages of NMP and PAMAM-NMP respectively.The results showed that the magnetic core of Fe3O4 was perfect with the average diameter 9 nm.FTIR proved the existence of NH2 with the absorption at 3 478 cm-1 and 3 300 cm-1.The content of N increased from 0.225% to 0.992% after enhanced by PAMAM and proved that the PAMAM provided more active groups for NMP.The deposition time within or without magnetic field was 16 h and 2 112 h respectively,which indicated that the better magnetic response and suspension were obtained by PAMAM-NMP.