Electro-rheological properties of transformer oil-based magnetic fluids

Abstract

The aim of this work was to study rheological behavior of nanofluids affected by electric field and temperature. We used transformer oil-based magnetic fluids, the suspensions of permanently magnetized colloidal particles (Fe3O4) coated by a stabilizing surfactant and immersed in transformer oil. The rheological characterization of transformer oil-based magnetic fluid was performed using the rotational rheometer MCR 502 in the shear rate from 10 to 1000 s-1.The strength of electric field was changed in the interval 0-6 kV cm-1. The flow curves and viscosity functions detected at three different temperatures 25, 50, and 75 °C disclose rheological characteristics of samples, first of all the viscosity growth under increasing strength of electric field.