Next-generation ecofriendly MR fluid: Hybrid GO/ Fe2O3 encapsulated carbonyl iron microparticles with improved magnetorheological, tribological, and corrosion resistance properties

In this study, magnetorheological fluid (MRF) was developed using hybrid core-shell particles. The core of these particles consists of carbonyl iron (CI), while the shell is composed of graphene oxide (GO) and iron oxide (Fe2O3) nanocomposite particles. The hybrid nanocomposite and core-shell particles were synthesized through a simple wet stirring process. A blended biocompatible oil comprising 90% rice bran oil and 10% silicone oil was employed as the continuous phase to ensure environmental and economic feasibility. Various characterization techniques were employed to examine the surface, structural, and magnetic properties of the hybrid core-shell particles. Magnetorheological (MR) measurements demonstrated that the incorporation of GO/Fe2O3 nanocomposite particles onto the CI particles (CIPs) significantly enhanced the shear stress and yield stress properties of the resulting MRF. This improvement can be ascribed to an increase in the magnetic saturation resulting from the encapsulation of GO-decorated Fe2O3 nanocomposite particles. The corrosion resistance and sedimentation properties were evaluated in this study, and the hybrid core-shell particles exhibited superior results compared to the bare CIPs. In terms of tribological performance, the hybrid core-shell particles exhibited significant improvement in friction and wear properties in comparison to the bare CIPs-based MRF and dry sliding condition. The significant reduction in coefficient of friction (COF) and wear might be attributed to the development of a lubricating protective layer consisting of bare CIPs and hybrid core-shell particles-based MR fluids (MRFs) at the contact interface. Consequently, this study offers an economical and effective approach for formulating MRFs with desirable rheological and tribological characteristics and corrosion inhibition properties, making them suitable for various environmental and industrial applications.