Two-dimensional Fe₃O₄/MoS₂ nanocomposites for a magnetorheological fluid with enhanced sedimentation stability

Superparamagnetic Fe₃O₄ nanoparticles were successfully deposited on the surface of MoS₂ nanosheets (Fe₃O₄/MoS₂) by a sonochemical method and the obtained Fe₃O₄/MoS₂ nanocomposites were used as a promising candidate for a magnetorheological (MR) fluid. This MR fluid was prepared from the Fe₃O₄/MoS₂ nanocomposites and its corresponding MR performances were examined using a rotational rheometer. The MR fluid based on Fe₃O₄/MoS₂ showed typical MR effects with increasing viscosity, shear stress, yield stress and dynamic shear modulus depending on the applied magnetic fields. Compared with commercial carbonyl iron (CI) particles, the sedimentation stability of the Fe₃O₄/MoS₂-MR fluid was greatly improved because of its unique two-dimensional structure and the reduced fluid-particle density mismatch. Therefore, the prepared Fe₃O₄/MoS₂-based MR fluid with typical MR effects and good sedimentation stability would have great potential in practical applications.