Preparation and magnetorheological properties of aqueous suspension based on emulsion droplets containing Fe_3O_4 nanoparticles

摘要

The Fe_3O_4 nanoparticles with mean size of 10 nm were prepared by chemical common precipitation . the factors influencing the size and shape of Fe_3O-4 nanoparticles such as the adding rate of NaOH to the mixed solution and the final pH of the solution were stud- ied. The Fe_3O_4 based magnetorheological(MR) fluid was formed by adding surfactant. The rheological properties of this MR fluid were studied when the magnetic fields with different direction are applied. It has been found that the MR fluid has the magnetic anisotropy.