Preparation and magnetorheological characteristics of polymer coated carbonyl iron suspensions

Core-shell structured magnetic carbonyl iron (CI)-poly(methyl methacrylate) (PMMA) particles were fabricated via CI-seeded dispersion polymerization method, in order to enhance dispersion stability of their magnetorheological (MR) fluid when dispersed in mineral oil. The rheological properties of MR fluid with core-shell structured magnetic particles were then measured via a rotational rheometer with a magnetic field generator. It was found that the synthesized core-shell structured encapsulated CI particles possess better dispersion stability in suspending oil than bare CI particle suspension, due to the density reduction of the particles. (C) 2006 Elsevier B. V. All rights reserved.