超顺磁性纳米Fe3O4的热分解法制备及表征

以单甲氧基聚乙二醇、对甲苯磺酰氯、邻苯二甲酰亚胺钾等为原料,根据盖布瑞尔合成法原理,合成了一端为氨基的单甲醚聚乙二醇(mPEG-NH2)。并以其为还原剂,聚乙二醇(PEG)为溶剂,利用热分解法制备了水分散性的超顺磁性纳米Fe3O4。采用红外光谱(FT-IR)、X射线衍射(XRD)、透射电镜(TEM)、热重分析(TG)、超导量子干涉仪(SQUID)和纳米粒度与Zeta电位分析仪等测试技术对其性能进行表征,实验结果表明,所制得的纳米Fe3O4粒子结晶度高,粒度均匀,分散良好,平均粒径为(12.2±1.6)nm,具有超顺磁性,饱和磁化强度为54 emu/g,在中性水溶液中其表面带正电,Zeta电位为+33 mV。TG测试结果表明,Fe3O4纳米粒子表面有机物的含量约为28%,Fe3O4的产率为57%左右。

Preparation and Characterization of Superparamagnetic Magnetite Fe3O4 Nanoparticles

Using monomethoxypoly(ethy1ene glycol)(mPEG),p-toluenesulfonyl chloride(TsCl) and potassium salt of phthalimide(PPI) as raw materials,amino-monomethoxypoly(ethy1ene glycol)(mPEG-NH2) was synthesized based on the principle of Gabriel synthesis.Then water-soluble magnetite nanoparticles was fabricated by thermal decomposition of iron(III) acetylacetonate(Fe(acac)3) in polyethylene glycol(PEG) solvent using mPEG-NH2 as the reducing agent.The products was characterized by FT-IR,XRD,TEM,TG,superconductivity quantum interference device(SQUID) and laser particle size and Zeta potential analyzer.FT-IR analysis showed that the target product mPEG-NH2 was achieved.XRD patterns show that magnetite nanoparticles had the face centered cubic(fcc) crystal structure.The morphology analysis by TEM confirmed that magnetite nanoparticles had a relatively uniform size distribution with the average diameter of(12.2±1.6) nm.The Zeta potential distribution plot of the magnetite nanoparticles in an aqueous suspension(pH=7) was +33 mV.The magnetization curve measured by SQUID showed the nanoparticles had superparamagnetic characteristics and the saturation magnetization were 54 emu/g at 300 K.The results of TG analysis indicated that the coating amount of copolymer on Fe3O4 nanoparticles was 28%.The yield of Fe3O4 was estimated to be about 57%.