巨电流变液研究进展

 巨电流变液具有很好的流变性能，其特性用传统电流变液模型无法解释，要认识巨电流变液的物理机制并完善、提高其性能，须提出新的物理模型。综述了尿素包覆Ba-Ti-O纳米颗粒电流变液、极性分子型电流变液、极性分子饱和取向极化模型等巨电流变液的发现过程和研究进展。分析表明，现有理论模型都是在相对简单的物理模型上提出的，尚不能很好解释巨电流变液中的所有现象，在计算处理上也需做近似和假定参数，因而具有一定局限性。这不仅仅是因为液相黏度、颗粒介电特性、包覆层特性、极性分子、表面改性、工作温度、浓度等多种因素共同作用而导致的复杂性，还可能有尚未认识的因素在其中起关键作用。

Progress of Studies of Giant Electro-rheological Fluids

Giant Electro-Rheological(GER) fluids enjoy perfect rheological properties, which can not be fully explained by models of conventional electro-rheological fluids. In order to improve performance of GER fluids, it is necessary to establish new models for GER fluids based on their physical mechanism. In this paper, the progress of studies of different types of GER fluids is reviewed, including GER fluids developed by nanoparticles coated with urea, polar molecule type ER fluids and the model of saturated orientational polarization of polar molecule. Although great advancement is made in understanding the mechanisms of GER fluids by the current theoretical models, they are all based on respective simplified assumptions and can not explain all phenomena satisfactorily, which has limited their general applications. Besides the complexity induced by viscosity of liquids, dielectric properties of particles, characteristics of coating layer, polar molecules, surface modification, temperature, concentration and other unknown factors are likely to play some roles.