全氟碳油基磁性液体的制备及性能研究

发布时间：2018-05-13 22:19

  本文选题：全氟碳油 + 磁性液体　； 参考：《沈阳工业大学》2017年硕士论文

【摘要】：本文采用VZD-400型直流电弧等离子体法,在总压力为8×104Pa,的混合气氛下,蒸发Fe-Ni合金和纯Ni制备了Fe-Ni@SiO_2、Ni@SiO_2合金纳米粒子。并以全氟碳油为基液,油酸和十二烷基苯磺酸钠修饰的Ni@SiO_2、Fe-Ni@SiO_2合金纳米粒子作为磁性粒子制备了全氟碳油基磁性液体。本文通过用透射电子显微镜(TEM)、X射线衍射(XRD)、X光电子谱(XPS)及BKT-4500型振动样品磁强计(VSM)等测试技术,对已制备出的磁性纳米粒子的形貌、粒度、相组成、表面特性以及磁性等进行了表征。对制备的全氟碳油基磁性液体的磁性、粘度及流变特性用振动样品磁强计(VSM)和粘度计进行研究。研究结果可以得到,Ni@SiO_2、Fe-Ni@SiO_2合金纳米粒子均为类球形,其中Ni@SiO_2粒子外包覆层的厚度大约为2-5nm,粒度分布为10-35nm,Ni@SiO_2纳米粒子随磁场强度的增加其磁化强度程增大趋势,当磁场增加到200KA/m时,磁性纳米粒子的磁化强度趋于饱和状态,其饱和磁化强度为25Am2/kg。Fe-Ni@SiO_2合金纳米粒子颗粒度分布为20-60nm,其表面包覆层厚度为3-4nm。在室温下,测量出不同浓度的FeNi@SiO_2合金纳米粒子的饱和磁化强度为60-70Am2/kg,当温度高于200℃后,其饱和磁化强度开始减小。无论是Ni@SiO_2还是Fe-Ni@SiO_2的全氟碳油基磁性液体,其粘度都随纳米粒子浓度含量的增加而不断增大,随温度的升高呈减小趋势,但并不遵循严格的线性关系。Ni@SiO_2和Fe-Ni@SiO_2的全氟碳油基磁性液体的饱和磁化强度都随纳米粒子浓度含量的增加而不断增大,也不遵循严格的线性关系。在常温下,Ni@SiO_2纳米粒子浓度含量在5wt%-50wt%时,粘度范围为1.47×10~3mPa·S-1.96×10~3mPa·S,饱和磁化强度范围为0.41Am2/kg-4.5Am2/kg。Fe-Ni@SiO_2合金纳米粒子浓度为10wt%-45wt%,25℃时,其粘度范围为1.92×10~3mPa·S-2.53×10~3mPa·S,饱和磁化强度范围为0.45Am2/kg-9.2Am2/kg,85℃时,粘度范围为1.33×10~3mPa·S-1.66×10~3mPa·S。全氟碳油基磁性液体的粘度随剪应力的增大而减小,当将剪应力增大到一定程度其粘度趋于稳定,以Ni@SiO_2纳米粒子浓度5wt%为例,当剪应力增加到272017mPa时,其粘度稳定在1307mPa·S。
[Abstract]:In this paper, Fe-NiSiO2-NiSiO-2 alloy nanoparticles were prepared by VZD-400 DC arc plasma method in a mixed atmosphere of 8 脳 10 ~ 4 Pa. by evaporating Fe-Ni alloy and pure Ni. Perfluorocarbon oil-based magnetic fluids were prepared by using perfluorocarbon oil as base liquid, oleic acid and sodium dodecylbenzene sulfonate modified Niearth SiO2Fe-NiSiO-2 alloy nanoparticles as magnetic particles. In this paper, the morphology, particle size and phase composition of the prepared magnetic nanoparticles have been studied by means of transmission electron microscopy (TEM) and X-ray diffraction (XPS) and BKT-4500 vibrating sample magnetometer (VSM). Surface properties and magnetic properties were characterized. The magnetic, viscosity and rheological properties of the prepared perfluorocarbon oil based magnetic fluids were studied by vibrating sample magnetometer (VSM) and viscometer. The results show that the nanocrystalline Ni@SiO_2 particles are spherical, and the thickness of the outer coating of the Ni@SiO_2 particles is about 2-5 nm, and the particle size distribution is 10-35 nm. The magnetization range of the NiSiO2 nanoparticles increases with the increase of the magnetic field intensity. When the magnetic field increases to 200KA/m, The magnetization of magnetic nanoparticles tends to be saturated. The saturation magnetization of 25Am2/kg.Fe-Ni@SiO_2 alloy nanoparticles is 20-60 nm and the coating thickness is 3-4 nm. At room temperature, the saturation magnetization of different concentrations of FeNi@SiO_2 nanoparticles was measured to be 60-70 Am2 / kg. When the temperature was above 200 鈩，

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