Aspects Concerning the Fabrication of Magnetorheological Fluids Containing High Magnetization FeCo Nanoparticles

Recently, our collaborative work in the fabrication of a magnetorheological fluid (MRF) containing high magnetization FeCo nanoparticles (NPs, fabricated laboratories using chemical reduction technique; MS = 212 Am2/kg) as magnetic fillers have resulted new MRF with superior performance up to 616.7 kA/m. The had yield stress value 2729 Pa and good reversibility after demagnetization process. This competes best ones reported most recent literature. Nevertheless, process this type is not an easy task since there strong trend aggregation NPs due dipolar interaction among them. Thus, now we present analysis some aspects concerning MRF, mainly surfactant used cover those (oleic acid or aluminium stearate) its concentration, procedure followed (mechanical and/or ultrasound stirring) achieve dispersion within fluid.