极性分子型电流变液导电机理研究

Electrical conduction mechanism in polar molecule dominated electrorheological fluid

极性分子型电流变液是一种新型的电流变材料.其介电颗粒上吸附极性分子,极性分子在颗粒间强局域电场作用下发生取向是产生巨电流变效应的关键.通过对Ca—Ti—O(CTO)体系极性分子型电流变液电流密度的测量发现,其导电行为遵从Poole-Frenkel效应的规律,这是极性分子型电流变液的重要特征之一.而500℃处理过的CTO粉体不含极性分子,所配制的电流变液无巨电流变效应,其电流密度随外电场强度近似地呈线性关系,显示出传统电流变液特性。

Polar molecule dominated electrorheological（ER） fluid is a new type of ER material with high shear stress.The alignment of polar molecules adsorbed on the dielectric particles in the direction of the high local field between the particles plays a decisive role in such new ER fluids.In measuring the current density of ER fluid composed of Ca—Ti— O particles,it was found that the conductive behavior of the fluid exhibits Poole-Frenkel character,which is one of the particular features for polar molecule dominated electrorheological fluids.By heating the Ca—Ti—O particles at 500 ℃ to remove the polar molecules adsorbed on the particles,however,the current density of ER fluid fabricated with pure Ca— Ti—O particles has linear dependence on the electric field approximately,same as in the traditional ER fluids.