【摘要】 使用单分散Fe/SiO2椭球型微纳复合胶粒作为磁性微粒,将其用吐温20做表面修饰并分散于油性基液中制备得到磁性液体;使用流变仪对这种新型磁性液体的流变性能进行了研究。结果表明:该磁性液体在承受垂直磁场方向的小剪切率时,其粘度会随磁感应强度的增加而变大;当剪切率较大时,粘度会变得很小且基本不随磁感应强度的增加而改变;磁感应强度一定时,该磁性液体有明显的剪切稀化现象;另外,其在承受小幅振荡剪切载荷时会表现出与典型磁性液体不同的粘弹性特征。更多还原

【Abstract】 Magnetic fluids were prepared using monodispersed iron/silica(Fe/SiO2) ellipsoidal composite particles which were modified by Tween-20 and dispersed in an oily medium as the magnetic materials.The rheological properties of the magnetic fluids were studied by rheometer.The results showed that when the shear rate was small,viscosity of the magnetic fluids raised with the increase of the magnetic field strength.When the shear rate was large,viscosity became very samll and no longer changed with the increase of the magnetic field strength.When the magnetic field strength was certain,the magnetic fluids showed obvious shear thinning.Under small oscillator shear loads,the viscoelastic behavior of the magnetic fluids was different from that of the normal ones.更多还原