Ghasemi E, Mirhabibi A, Edrissi M
Institute of Color Science and Technology (ICST), 16688-14811 Tehran, Iran.
J Nanosci Nanotechnol. 2011 Jun;11(6):5285-91. doi: 10.1166/jnn.2011.3783.
An iron oxide ferrofluid with mean particle size of 10.6 nm was synthesized by co-precipitation. The nanoparticles were characterized using X-ray diffraction, transmission electron microscopy, electron energy loss spectroscopy, and dynamic light scattering. The magnetorheological properties of ferrofluid were investigated using a rotating rheometer. The effect of magnetic field on the aggregation of magnetic nanoparticles and rheological behavior were investigated. Moreover the effects of concentration and particle size on the magnetoviscousity of ferrofluid were studied. The results showed that the maghemite is the major magnetic phase. The magnetoviscous effect leads to phase separation at high magnetic fields which is dependent to the concentration. It was shown that the smaller particle sizes which are not contributed in magnetoviscous effect can contribute at higher magnetic fields.
通过共沉淀法合成了平均粒径为10.6 nm的氧化铁铁磁流体。使用X射线衍射、透射电子显微镜、电子能量损失谱和动态光散射对纳米颗粒进行了表征。使用旋转流变仪研究了铁磁流体的磁流变特性。研究了磁场对磁性纳米颗粒聚集和流变行为的影响。此外，还研究了浓度和粒径对铁磁流体磁粘性的影响。结果表明，磁赤铁矿是主要的磁性相。磁粘性效应导致在高磁场下发生相分离，这取决于浓度。结果表明，对磁粘性效应无贡献的较小粒径在较高磁场下可能会有贡献。
