Polyaniline (PANI)-coated iron oxide (Fe 3 O 4 ) sphere particles were fabricated and applied to a dual stimuliresponsive material under electric and magnetic fields, respectively. Sphere Fe 3 O 4 particles were synthesized by a solvothermal process and protonated after acidification. The aniline monomer tended to surround the surface of the Fe 3 O 4 core due to the electrostatic and hydrogen bond interactions. A core-shell structured product was finally formed by the oxidation polymerization

more »

... PANI on the surface of Fe 3 O 4 . The formation of Fe 3 O 4 @PANI particles was examined by scanning electron microscope and transmission electron microscope. The bond between Fe 3 O 4 and PANI was confirmed by Fourier transform-infrared spectroscope and magnetic properties were analyzed by vibration sample magnetometer. A hybrid of a conducting and magnetic particle-based suspension displayed dual stimuli-response under electric and magnetic fields. The suspension exhibited typical electrorheological and magnetorheological behaviors of the shear stress, shear viscosity and dynamic yield stress, as determined using a rotational rheometer. Sedimentation stability was also compared between Fe 3 O 4 and Fe 3 O 4 @PANI suspension.