Thixotropy of MR shear-thickening fluids

Particle sedimentation is a key issue of conventional magnetorheological (MR) fluids. We recently fabricated MR shear-thickening fluids (MRSTF), which can work as novel MR fluids without particle settling. This merit of the material against particle settling is attributed to the thixotropy property. By using shear-thickening fluids as a base medium, a series of MRSTF samples was prepared and their rheological properties were tested. It was found that when the weight fraction of the STF base is above a threshold value of 15%, the MRSTF exhibits a significant thixotropy phenomenon, which greatly reduces the settling problem of MR fluids and consequently increases the stability of MR fluids. A theoretical approach was proposed to verify the experimental studies.