The effect of nano-silica and nano-magnetite on the magnetorheological fluid stabilization and magnetorheological effect

Abstract

In this study, the effect of adding magnetizable and non-magnetizable nano particles (magnetite and fumed silica) to magnetorheological fluids was investigated experimentally. The results showed a great increase up to six times in magnetorheological effect when using magnetite in comparison to nano particle–free magnetorheological fluids. On the other hand, adding non-magnetizable silica made the suspension stable for more than 2000 h by somehow increasing magnetorheological effect. Herschel–Bulkley model fitted the experimental data well and shear thinning behaviour was observed in all synthesized magnetorheological fluids.

Magnetorheology: a review

“…big or small, spherical or not spherical, magnetically soft or hard, magnetic or non-magnetic, mechanically hard or soft, etc.). By using bidisperse MRFs one can improve dispersion stability, 95 reduce the off-state viscosity, 96 increase the MR effect 95,[97][98][99][100][101] and minimize the sedimentation. 97,98 First papers in this field explored mixing particles of different sizes (bimodal MRFs) with at least one particle in the micrometer range.…”

Influence of the Various Deformation Modes on Rheology of High-Concentrated Magnetorheological Fluids of Complex Composition for Controlled Layered Structures

“…A significant increase in shear stress was also obtained when adding 1% of γ-Fe 2 O 3 (Leong et al, 2016). The magnetorheological effect can be enhanced by several times with the use of magnetite additives (Ashtiani and Hashemabadi, 2015). A multiple increase in the components of the complex shear modulus and shear stress was also noted with the addition of non-magnetic particles of poly(methylmethacrylate) (Iglesias et al, 2015).…”

Performance and Stability of Magnetorheological Fluids—A Detailed Review of the State of the Art

“…Iron oxide has also been used in MRFs with other organic and inorganic additives. Korobko et al [ 101 ] reported shear stress of MRFs with CrO 2 additives to be greater than MRFs with γ‐Fe 2 O 3 or nonmagnetic SiO 2 in mineral oil, which the authors attribute to the higher M s and elongated structures of CrO 2 compared with γ‐Fe 2 O 3 and SiO 2 Ashtiani and Hashemabadi [ 102 ] found that MRFs with nonmagnetizable fumed silica exhibited higher off‐state viscosity, lower τ y values, and improved sedimentation stability as compared with MRFs with γ‐Fe 2 O 3 . Fu et al [ 103 ] observed that bidisperse MRF with a mixture of 15 wt% of gelatin‐coated CI and 2–5 wt% Fe 3 O 4 dispersed in polyolefin synthetic oil increased the sedimentation ratios of MRFs with increasing Fe 3 O 4 concentration.…”