Preparation and characterization of silica coated iron oxide magnetic nano-particles
Preparation and characterization of silica coated iron oxide magnetic nano-particles
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DOI：
10.1016/j.saa.2010.04.004
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发表时间：
2010-09-01
影响因子：
4.4
通讯作者：
Moussa, Filsun
中科院分区：
文献类型：
--
作者：
Li, Ying-Sing;Church, Jeffrey S.;Moussa, Filsun
在碱性条件下，以氯化铁和三氯化铁为原料，采用沉淀法制备了氧化铁磁性纳米粒子。通过使用正硅酸乙酯（TEOS）和巯丙基三甲氧基硅烷（MPTMS）进行表面改性。用透射电子显微镜（TEM）、能量色散X射线（EDX）光谱、热重分析（TGA）、红外（IR）和拉曼光谱对未涂覆和涂覆的颗粒进行了表征。发现从TEM图像测量的颗粒尺寸对于未涂覆的颗粒具有13nm的平均直径，对于涂覆的颗粒具有约19nm的平均直径。测量的未涂覆和MPTMS涂覆的颗粒的IR光谱显示在高温下磁铁矿转化为赤铁矿。从IR光谱和TGA获得的结果表明，在MPTMS涂覆的磁铁矿中的巯基丙基甲硅烷基在600 ℃下分解，并且TEOS涂覆的磁铁矿的二氧化硅层相当稳定。拉曼光谱显示了通过磁铁矿转化为磁赤铁矿和赤铁矿的激光加热效应。(C)2010 Elsevier B.V.保留所有权利。
Iron oxide magnetic nano-particles have been prepared by precipitation in an aqueous solution of iron(II) and iron(III) chlorides under basic condition. Surface modifications have been carried out by using tetraethoxysilane (TEOS) and mercaptopropyltrimethoxysilane (MPTMS). The uncoated and coated particles have been characterized with transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, thermal gravimetric analysis (TGA), and infrared (IR) and Raman spectroscopy. The particle sizes as measured from TEM images were found to have mean diameters of 13 nm for the uncoated and about 19 nm for the coated particles. The measured IR spectra of the uncoated and MPTMS coated particles showed the conversion of magnetite to hematite at high temperature. The results obtained from both IR spectroscopy and TGA revealed that the mercaptopropylsilyl group in the MPTMS coated magnetite decomposed at 600 degrees C and the silica layer of the TEOS coated magnetite was rather stable. Raman spectroscopy has shown the laser heating effect through the conversion of magnetite to maghemite and hematite. (C) 2010 Elsevier B.V. All rights reserved.