An Exotic Phase Change in Dynamic Electrorheological Fluids  

作　　者：唐强果 黄俊樱 李丛 郑杰 孟现文 黄吉平 周鲁卫 

机构地区：[1]Department of Physics and State Key Laboratory of Surface Physics Fudan University [2]College of Information Technology Shanghai Ocean University

出　　处：《Communications in Theoretical Physics》2015年第1期77-85,共9页理论物理通讯（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos.10334020,10974030,10574027,11222544;the Fok Ying Tung Education Foundation under Grant No.131008;the Program for New Century Excellent Talents in University(NCET-120121);the CNKBRSF under Grant No.2011CB922004

摘　　要：It is well known that constant or time-varying electric fields can induce phase changes in electrorheological(ER) fluids, from a liquid to semi-solid state, provided the field strength is larger than some critical value. We describe here an experimental and theoretical study considering yet a different class of phase changes, specifically those for an ER fluid in the presence of both shear flow and a time-varying electric field. We note that as the frequency of the field is decreased, the ER fluid will go from a liquid to an intermediate transition state, and eventually to a shear banding state. Our theoretical analysis further indicates that this phase change originates from competing effects of viscous and electrical forces. Ultimately, we conclude that it is possible to achieve various states and corresponding(desired)macroscopic properties of dynamic colloidal suspensions by adjusting the frequency of the externally applied electric field.

关 键 词：electrorheological （ER） fluids electric field transition state 

分 类 号：O441.1[理学—电磁学]