Abstract
Composite magnetic particles (CMPs) having a carbonyl iron (CI) core and N-glucose ethylenediamine triacetic acid (GED3A) shell were prepared by an in situ chelating reaction, where the CI surface was coated with GED3A. The properties of thus obtained CMPs, including morphology, structure, and magnetic behaviors, were characterized using scanning electron microscopy (SEM), tunneling electron microscopy (TEM), Fourier transform-infrared (FT-IR), and a vibrating sample magnetometer (VSM). Based on the CMPs, a novel kind of aqueous magnetorheological (MR) fluid was prepared. The magnetorheological properties were analyzed via a strain-controlled rheometer equipped with a magnetic field source in parallel-plate geometry. It was found that the MR fluids exhibited high shear and/or yield stress and a rapid response to magnetic field. Furthermore, the dispersion stability and the anti-oxidation properties were substantially improved as revealed by stability tests.