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. (C) 2011 Elsevier B.V. All rights reserved.