Effect of polymer coating on the behavior of an electro–rheological fluid in slit flow

Electro–rheological (ER) effect is the term applied to the rapid and reversible changes in rheological properties of certain suspensions or solutions under the application of an electric field. In this study, the dependence of ER-effects of an ER-fluid in rotational as well as in slit flow on electric field strength, field frequency, shear rate and volumetric flow rate was quantified using the Casson model. In addition, the effects of coating the electrodes with a polymer mesh (trevira) on the behavior of an ER-fluid in slit flow were investigated. The results showed that with the trevira mesh on the surface of the electrodes, the ER-fluid demonstrated greater increase in the pressure drop upon the application of both AC- and DC- field. Compared to the uncoated electrodes, the relative ER-effects for the electrodes with the trevira mesh were 1.12–4.23 times larger. On the other hand, the ER-effect of the ER-fluid used can be increased by installation of trevira mesh without increasing the current levels under constant electric field strength.