Polyol合成法制备生物医药用超小粒径Fe_3O_4磁性纳米晶体

Polyol Synthesis of Ultrasmall Fe_3O_4 Magnetic Nanocrystals for Biomedical Applications

采用一罐polyol合成法还原Fe(Ⅲ)乙酰丙酮化合物制备了粒径可调、单分散、直径5nm以下的磁性Fe3O4纳米晶体.其晶粒表面为所用聚合物表面活性剂PVP所包覆.运用透射电镜/高分辨透射电镜、X射线衍射、振动样品磁强计和超导量子干涉仪对其结构和性能进行了表征.结果表明所制得的Fe3O4磁性纳米晶体在室温下显示出优良的超顺磁性,且结晶度高、分散性好、化学性质稳定同时表面易修饰.磁滞回线的模型分析说明该Fe3O4纳米晶粒是磁性单畴.该法制得的超顺磁Fe3O4纳米晶粒在生物和医学领域具有重要的应用价值.

Sub-5nm uhrasmall nanosized Fe3O4 nanoerystals were synthesized by reduction of Fe（Ⅲ） aeetylaeetonate in the presence of polyvinylpyrrolidone（PVP） polymer as surfactant in one-pot polyol process. The particle size was tailored by the amounts of the precursor. The nanocrystals were investigated by XRD, TEM/HRTEM and VSM/SQUID. It is found that the nanoerystals have high crystallinity with distinct lattices, while the magnetic measurements revealed their well-defined superparamagnetie behavior at room temperature. Model analysis demonstrates that the magnetite nanoerystals exist in magnetic monodomains. Such PVP-coated Fe3O4 nanocrystals with tunable dimension and thus magnetic properties are promising for biomedical applications.