A novel carrier liquid with high steric hindrance for enhancing the comprehensive properties of MR fluids

Magnetorheological (MR) fluids can rapidly shift between solid and liquid phases in response to changes in an applied magnetic field, which can be precisely controlled by the external environment. This capability underscores the significant potential of MR fluids in damper applications. However, the main challenge is the difficulty in simultaneously enhancing their key properties, which constrains their development potential. In this study, we propose using a novel phenylmethyl siloxane (PSO) with high steric hindrance as the carrier fluid to enhance the overall performance of MR fluids. Compared with conventional dimethyl siloxane (SO) carrier liquid, the PSO carrier fluid, despite its lower viscosity, demonstrated a 17 % enhancement in shear yield strength at the magnetic field of 280 kA/m and a 5 % improvement in sedimentation stability. The Molecular dynamics simulations further confirmed that the presence of benzene side groups, compared to methyl groups, confers superior resistance to deformation and steric hindrance. Consequently, this enhances the shear stress and sedimentation stability of MR fluids during shear deformation. By conducting the comprehensive analysis of experimental results and numerical simulations, this study has deepened our understanding of the intricate relationship between the characteristics of carrier liquid and MR fluids.