Plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids

The aim of this paper is to document suitability of plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids. Surface-modified carbonyl iron particles were prepared via their exposure to 50% argon and 50% octafluorocyclobutane plasma. The X-ray photoelectron spectroscopy was used for analysis of chemical bonding states in the surface layer. Plasma-treated particles were adopted for a dispersed phase in magnetorheological (MR) fluids, and the MR behaviour was investigated using rotational rheometer equipped with magnetic field generator. Viscoelasticity changes of MR fluids were measured in the small-strain oscillatory shear flow as a function of the strain amplitude, frequency and the magnetic flux density. The MR fluids based on plasma-treated particles exhibit promoted suspension stability, which is attributed to the interactions between fluorine bonded on particle surface and methyl groups of silicone oil.