Graphene @Fe3O4 compound organic magnetorheological fluid and preparation method thereof

The invention relates to the field of intelligent magnetic materials and in particular relates to a graphene @Fe3O4 compound organic magnetorheological fluid and a preparation method thereof, solving the problems that existing magnetorheological fluids are easy to settle and the stability and magnetorheological effects of the magnetorheological fluids are difficult to optimize at the same time. The preparation method comprises the following steps: adding an organic solvent to FeCl2.4H2O and FeCl3.6H2O to prepare a Fe3O4 organic magnetic fluid; adding cellulose or imidazole to the organic solvent to prepare a homogeneous solution, then adding expanded graphite and carrying out ultrasonic dispersion to prepare a graphene organic solution; finally adding a surfactant, the Fe3O4 organic magnetic fluid and an organic radical carrier fluid to the graphene organic solution and carrying out ultrasonic dispersion, thus obtaining the stable graphene @Fe3O4 compound organic magnetorheological fluid, wherein magnetic particles are graphene @Fe3O4 and account for 10-30wt% of the graphene @Fe3O4 compound organic magnetorheological fluid. The method has the advantages of good stability, low zero field viscosity, high shear strain and wide operating temperature range.