Fe_3O_4@SiO_2硅油基磁性液体制备及其性能研究  

Preparation and performance studies of Fe_3O_4@SiO_2 silicon oil based magnetic fluid

作　　者：柏乐 张志力[1] 许龙飞[1] 邸楠楠 李德才[1] 

机构地区：[1]北京交通大学机械与电子控制工程学院,北京100044

出　　处：《功能材料》2017年第11期11103-11107,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(61271049);装备预研教育部联合基金资助项目(6141A02022216)

摘　　要：通常情况下硅油的粘度随温度变化非常小,表现出优良的"耐温性",是其作为工作介质在特殊环境下的突出优点。将硅油的"耐温性"与磁性液体相结合,可以极大地扩宽磁性液体的应用领域。采用化学共沉淀法和正硅酸乙酯水解法制备了Fe_3O_4@SiO_2核壳型磁性颗粒,在制备Fe_3O_4@SiO_2磁性颗粒时,主要针对反应物添加顺序、前驱体溶液pH值、包覆温度、包覆剂用量等影响因素设计实验并优化了实验工艺。然后用硅烷偶联剂A1120对其包覆,采用超声分散与高能球磨振荡相结合的分散方式将包覆后的Fe_3O_4@SiO_2磁性颗粒分散在硅油基载液中,制备了硅油基磁性液体。通过振动样品磁强计(VSM)、红外光谱仪(IR)、X射线衍射仪(XRD)、透射电子显微镜(TEM)等多种手段对纳米磁性颗粒进行了表征,并对硅油基磁性液体的流变性能、稳定性等进行了分析。结果表明,核壳型纳米磁性颗粒的粒径为15~20nm,单分散度高,具有超顺磁性;硅油基磁性液体的饱和磁化强度达2.51×10^(-2) T,具有优良的稳定性和粘温性能。Under normal circumstances,the viscosity of silicone oil varies very little with temperature and exhibits excellent ＂temperature resistance＂.It is the outstanding advantage of silicone oil as a working medium in a special environment.By combining the ＂temperature resistance＂ of silicone oil with magnetic fluid,the application field of magnetic fluid can be greatly broadened.The core-shell magnetic particles Fe3O4@SiO2 were prepared by chemical coprecipitation and hydrolysis of ethyl orthosilicate.In the preparation of magnetic particles,the experimental process was mainly designed and optimized by orthogonal test analysis according to the factors such as the addition sequence of reactants,pH of precursor solution,coating temperature and the amount of coating agent.Then the magnetic particles were coated with silane coupling agent A1120.The coated magnetic particles were dispersed in silicone oil by the dispersion method of ultrasonic dispersion and high energy ball milling to prepare silicone oil based magnetic fluid.By using vibrating sample magnetometer,infrared spectroscopy,X-ray diffraction,transmission electron microscopy and other testing methods,the magnetic particles were characterized and the stability and rheological properties of silicon oil based magnetic fluid were analyzed.The results indicate that core-shell nano-magnetic particles are monodisperse and superparamagnetic with a particle size of 15-20 nm.The silica-based magnetic fluid has a saturation magnetization of 2.51×10-2 T and shows excellent stability and viscosity-temperature performance.

关 键 词：磁性液体 制备 硅油 Fe3O4@SiO2核壳型纳米磁性颗粒 表征 

分 类 号：TB332[一般工业技术—材料科学与工程]