Shi Lihong, Tam Wing Yim, Huang Xianxiang, Sheng Ping
Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 May;73(5 Pt 1):051501. doi: 10.1103/PhysRevE.73.051501. Epub 2006 May 9.
We report measurements of the static shear modulus of electrorheological (ER) fluids consisting of water-wetted silica microspheres in silicone oil. A shear-annealing method, using creep-recovery (CR) cycles under an external electric field, is used to enhance ER properties of the fluid. The shear-annealing method enables the silica spheres in the ER fluid to form better aligned and denser column microstructures. A stable state with elastic shear deformation is obtained after a sufficient number of CR cycles, with an optimal combination of stress duration and shear strength. Static shear modulus is obtained by measuring the elastic deformations at different shear stresses for an electric field frequency from 10 to 1000 Hz. A water-bridge model is proposed to explain the enhanced shear modulus.
我们报告了由硅油中水润湿性二氧化硅微球组成的电流变（ER）流体的静态剪切模量的测量结果。一种在外部电场下使用蠕变 - 恢复（CR）循环的剪切退火方法被用于增强流体的电流变性能。该剪切退火方法能使电流变流体中的二氧化硅球体形成排列更好且更致密的柱状微结构。在经过足够数量的CR循环后，通过应力持续时间和剪切强度的最佳组合，可获得具有弹性剪切变形的稳定状态。通过测量电场频率在10至1000Hz时不同剪切应力下的弹性变形来获得静态剪切模量。提出了一种水桥模型来解释增强的剪切模量。
