Enhanced magnetorheological performance of carbonyl iron/natural rubber composite elastomer with gamma-ferrite additive

Magnetorheological (MR) elastomers have attracted considerable attention for their potential applications but their MR efficiency requires significant improvement before they can be used commercially. In this study, rod-shaped hard magnetic gamma-ferrite (γ-Fe2O3) nanoparticles were added to a carbonyl iron (CI)@natural rubber (NR) composite elastomer to enhance the MR effect of CI-based MR elastomers. The surface morphological state of the dispersed magnetic particles was tested using scanning electron microscopy, and the fracture profiles of the MR elastomers made of magnetic particles were observed to be anisotropically aligned by mapping using energy dispersive X-ray spectroscopy. MR properties of the MR elastomers based on pure CI and CI@ γ-Fe2O3 were examined using a rotational rheometer under different magnetic field strengths with an enhanced MR efficiency of about 25%.