| 초록 |
Carbonyl iron (CI) based magnetorheological (MR) fluids have several drawbacks, including sedimentation of CI particles due to high density, difficulties in redispersion after hardening, and rust of iron by oxidation. Therefore we prepared MR fluids using carbonyl iron (CI) particles coated with polyvinyl butyral (PVB) by solvent casting. Depending on the amount PVB used, we also prepared modified CI particles with different particle density. Morphology of both CI and CI-PVB particles was observed by scanning electron microscopy (SEM). CI and CI-PVB particles were then suspended in Yubase oil with dispersants and their MR characteristics were examined using a rotational rheometer. It was found that yield stress and shear viscosity were changed compared with those of raw CI based MR fluid. |
