Dielectric criteria for the electrorheological effect
Dielectric criteria for the electrorheological effect
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DOI：
10.1021/la981069b
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发表时间：
1999-01
期刊：
影响因子：
3.9
通讯作者：
Tian Hao;A. Kawai;F. Ikazaki
中科院分区：
文献类型：
--
作者：
Tian Hao;A. Kawai;F. Ikazaki
电流变液的悬浮颗粒在外加电场作用下可以很容易地排列成体心四方晶格的微晶。因此，这个过程的熵，通常被认为是一级相变，将大大减少。由此，我们从理论上推导出分散颗粒材料的介电损耗角正切最大值应大于0.1，这与目前观察到的实验结果相一致，只有当d∈ sp /dT < 0时，负电流变效应才成为可能，其中∈ sp是分散颗粒材料的静态介电常数，T是温度。
The suspended particles of an electrorheological (ER) fluid can be easily arrayed as a crystallite of a body-centered tetragonal (bct) lattice structure using an external electric field. Thus the entropy of this process, which is generally recognized as a first-order phase transition, would greatly decrease. From this fact, we theoretically derive that the dielectric loss tangent maximum value of the dispersed particles should be larger than 0.1, which agrees well with the currently observed experimental results; the negative ER effect becomes possible only when d∈ sp /dT < 0, where ∈ sp is the static dielectric constant of the dispersed particle material and T is temperature.