Effect of sodium oleate as a buffer on the synthesis of superparamagnetic magnetite colloids
Effect of sodium oleate as a buffer on the synthesis of superparamagnetic magnetite colloids
复制标题
油酸钠作为缓冲剂对超顺磁性磁铁矿胶体合成的影响
DOI：
10.1016/j.jcis.2010.02.055
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发表时间：
2010-07-01
影响因子：
9.9
通讯作者：
Gu, Zhongwei
中科院分区：
文献类型：
--
作者：
Jiang, Wen;Wu, Yao;Gu, Zhongwei
将氯化铁、氢氧化钠（NaOH）和油酸钠（NaOL）分别溶解于甲苯/乙醇/水混合溶剂中，搅拌4 h，制备了粒径约为5 nm的超顺磁性单分散磁铁矿胶体。通过改变NaOH和NaOL的浓度，系统地研究了对磁铁矿纳米颗粒（MNP）的表面性质、尺寸、分散性和磁性能的影响。采用XRD、FTIR、TGA、TEM、SAED、DLS和VSM等手段对样品进行了表征。结果表明，通过增加NaOH/Fe（II）的摩尔比大于8，可以控制MNP的表面涂层从油酸基到羟基。NaOH用量对纳米粒子的粒径和饱和磁化强度没有明显影响。因此，NaOH不是形成磁铁矿晶体的必要反应物。相反的，我不知道。NaOL被证明是合成稳定的磁铁矿胶体的最重要组分。NaOL既充当缓冲pH环境的关键反应物，又充当保持MNP在非极性溶剂介质中稳定的表面活性剂。(C)2010年由Elsevier Inc.出版
In this study, superparamagnetic monodisperse magnetite colloids, around 5 nm in size, were prepared by dissolving iron chlorides, sodium hydroxide (NaOH) and sodium oleate (NaOL), in toluene/ethanol/water mixtures and refluxing for 4 h. The concentrations of NaOH and NaOL were varied to systematically investigate the effect on the surface properties, size, dispersion, and magnetic properties of magnetite nanoparticles (MNPs). The samples were characterized via XRD, FTIR, TGA, TEM, SAED, DLS, and VSM. The results indicated that the surface coatings of MNPs could be manipulated from oleate to hydroxyl groups via increasing the molar ratio of NaOH/Fe(II) more than 8. The amount of NaOH had no obvious influence on the size and the saturation magnetization of MNPs. Therefore NaOH was not a necessary reactant for forming magnetite crystals. On the contrary. NaOL was shown to be the most important component for synthesizing stable magnetite colloids. The NaOL acted as both a key reactant to buffer the pH environment and a surfactant to keep the MNPs stable in nonpolar solvent media. (C) 2010 Published by Elsevier Inc.