▎ 摘　　要

In this study, magnetic and semiconducting Fe3O4@graphene oxide (GO)-polystyrene (PS) composite particles were fabricated using the Pickering emulsion polymerization technique. The Fe3O4@GO composite particles were initially synthesized via a co-precipitation method and then used as a Pickering emulsifier. The basic properties, such as the morphology, chemical properties, and the magnetic properties of the Fe3O4@GO-PS composite particles, were characterized using transmission electron microscopy, Fourier -transform infrared spectroscopy, and VSM. The Fe3O4@GO-PS composite particles were then dispersed in silicone oil to obtain electrorheological (ER) and magnetorheological (MR) fluids. The ER and MR properties were tested using a rheometer with two different geometries under electric and magnetic fields. The ER dynamic yield stresses were obtained using the Bingham model fitting method, whereas the MR dynamic yield stresses were obtained using the Casson model fitting method. Furthermore, the yield stress was obtained by fitting the complex viscosity using the Carreau model. All three yield stresses were also fitted with respect to the electric or magnetic field strengths, and a slope of 1.5 was determined. (C) 2022 Elsevier B.V. All rights reserved.