Rheological Properties of Mg Substituted Cobalt Nickel Ferrite Nanoparticles as an Additive in Magnetorheological Elastomer

Abstract

Additive has been used widely in magnetorheological elastomer (MRE) fabrication in order to enhance the magnetic, electrical and rheological properties. In this study, the ferrite nanoparticles namely Magnesium (Mg) substituted Cobalt Nickel Ferrite is introduced as an additive in order to enhance the magnetic and rheological properties of MRE. The conventional co-precipitation method is used to synthesize the Mg substituted Cobalt Nickel Ferrite nanoparticles. The 1 wt% of spherical Mg substituted Cobalt Nickel Ferrite nanoparticles with a range size of 50 nm are then sonicated using ultrasonication before mixing with 70 wt% carbonyl iron particles (CIPs) and silicon-rubber (SR) as a matrix. Two prepared samples of MRE with and without Mg substituted Cobalt Nickel Ferrite nanoparticles are characterized using Vibrating Sample Magnetometer (VSM). Meanwhile, the rheological properties related to the frequency and magnetorheological (MR) effect in off- and on-state condition are determined by using rotational rheometer. The result depicted that the magnetic saturation of MRE with Mg substituted Cobalt Nickel Ferrite nanoparticles increased by 2%. Meanwhile, the maximum storage modulus of MRE with Mg substituted Cobalt Nickel Ferrite nanoparticles enhanced up to 13% as compared to conventional MRE. In the case of energy dissipation, the MRE + S1, exhibit higher energy dissipation as compared to conventional MRE. In the meantime, the relative MR effect of MRE with 1 wt% Mg substituted Cobalt Nickel Ferrite nanoparticles can reach up to 215%, as compared to conventional MRE. The enhancement of magnetic and rheological properties of MRE with Mg substituted Cobalt Nickel Ferrite nanoparticles suggest that the nanoparticles additive fill the void and improved the interaction between CIPs resulted in increment of storage modulus.