Two-dimensional FeO/MoS nanocomposites for a magnetorheological fluid with enhanced sedimentation stability.

Superparamagnetic FeO nanoparticles were successfully deposited on the surface of MoS nanosheets (FeO/MoS) by a sonochemical method and the obtained FeO/MoS nanocomposites were used as a promising candidate for a magnetorheological (MR) fluid. This MR fluid was prepared from the FeO/MoS nanocomposites and its corresponding MR performances were examined using a rotational rheometer. The MR fluid based on FeO/MoS 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 FeO/MoS-MR fluid was greatly improved because of its unique two-dimensional structure and the reduced fluid-particle density mismatch. Therefore, the prepared FeO/MoS-based MR fluid with typical MR effects and good sedimentation stability would have great potential in practical applications.