Enhanced performance of nano-sized maghemite added carbonyl iron-based magnetorheological soft elastomer

Abstract

This study examined the MR effects of ferromagnetic rod-like γ-Fe2O3 nanoparticle additives on carbonyl iron (CI)-based magnetorheological (MR) soft elastomers. CI-based isotropic MR elastomers were fabricated using polydimethylsiloxane (PDMS) as the matrix, and silicone oil was added as a plasticizer to make the specimen softer and to enhance the MR properties. The morphology and particle distribution of the fabricated elastomers were analyzed via scanning electron microscopy. Dynamic mechanical spectroscopy was employed to examine the rheological behaviors of the MR elastomers with and without γ-Fe2O3 additive while magnetic fields (H) of varying strength were applied to the samples. The strain and frequency sweep measurements showed that the storage modulus increased with increasing magnetic field strength. Compared with the sample without γ-Fe2O3, the CI/γ-Fe2O3-based MR elastomer exhibited a higher modulus with the Payne effect and the largest enhancement of 15 % in the MR effect was achieved at H = 343 kA/m. The creep and recovery experiments revealed that the γ-Fe2O3 addition rendered the MR elastomer stiffer at all H while comparable recovery ratios were attained for both specimens.