▎ 摘　　要

Novel graphene oxide (GO) particle was introduced as an additive to soft magnetic carbonyl iron (CI) micron-sized particle based magnetorheological (MR) fluid to improve its sedimentation and agglomeration problems in which the MR fluid is a colloidal suspension of magnetizable particles dispersed in a nonmagnetic carrier. The added plate-like GO gap-fillers filled the interspaces of CI particles and improved the resistance to sedimentation. The MR properties of two systems with and without additives were evaluated and compared under different magnetic field strengths using a rotational rheometer. Morphology of pure CI and GO/CI mixture were examined via scanning electron microscopy (SEM) images, and X-ray diffraction (XRD) patterns confirm the differences between pure CI and GO/CI mixture further, the sedimentation problem was observed to be improved. (C) 2012 American Institute of Physics. [doi: 10.1063/1.3677671]