Scaling magneto-rheology based on Newtonian and non-Newtonian host fluids

Abstract

Rheology of a suspension is mainly determined by particle interactions and the host fluid rheology. By scaling rheological properties of different magnetorheological (MR) suspensions prepared with Newtonian and non-Newtonian (including shear thickening and shear thinning) host fluids, the competition between the particle interaction and the host fluid rheology could be clearly revealed. A simple normalizing method by considering the ratio of the magnetic force to viscous force experienced by particles is introduced. The shear stress curves of the three kinds of MR suspensions could be well scaled into the same master curve. The magnetic force maintains the particles structures under magnetic fields, while the viscous force is a destructive factor to the particle structures. Therefore, the magnetic force dominates the rheology of MR suspensions at low shear rates with small viscous force. While as the increase of shear rate to a very high value, particle chain structures under external magnetic fields might get similar to that under zero magnetic field because of the dominant role of the viscous force. This work clearly demonstrates the competition between the particle interaction and the viscous force experienced by particles, which finally dominates the particle structure inside of the MR suspension and its rheological behavior.