The enhanced magnetorheological performance of carbonyl iron suspensions using magnetic Fe₃O₄/ZHS hybrid composite sheets

Abstract

Two-dimensional magnetic Fe 3 O 4 /ZHS hybrid composite sheets were prepared via a two-step microwaveassisted solvothermal synthesis. The successful incorporation of Fe 3 O 4 nanoparticles synthesized in the first step into a zinc hydroxysulfate (ZHS) sheet-like structure formed during the second synthesis step was confirmed by X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. The obtained magnetic Fe 3 O 4 /ZHS hybrid composite particles show a hexagonal and sheet-like morphology.The addition of these sheet-like hybrid composite particles into magnetorheological carbonyl iron-based suspensions results in a significant increase in MR performance. Moreover, this addition considerably contributes to the redispersibility enhancement of prepared suspensions in comparison to those consisting only of bare carbonyl iron particles.

Synthesis and Effect of Hierarchically Structured Ag-ZnO Hybrid on the Surface Antibacterial Activity of a Propylene-Based Elastomer Blends

“…Thermal decomposition of zinc hydroxide nitrates yields spherical, connected microparticles of ZnO, which go on to form long chains and two-dimensional networks of polyhedral to rounded nanoparticles, as seen in Figure 2 e,h. The ZnO phase obtain this morphology during annealing as a legacy of original layered morphology of zinc hydroxide nitrates by topotactic transition [ 25 , 45 ]. The diameters of the ZnO nanoparticles range up to 100 nm in size.…”

Improved rheological properties of dimorphic magnetorheological gels based on flower-like carbonyl iron particles

“…Jiang et al [19] employed Fe nanowires into the conventional carbonyl iron particles (CIPs) based MR fluids to prepare dimorphic MR fluids and got a greatly enhanced dynamic yield stress. In addition, Piao et al [20] and Machovsky et al [21] were reported separately that the addition of polyaniline/Fe composite nanofiber and Fe 3 O 4 /ZHS hybrid composite sheets into the CI based MR suspensions results in a significant increase in MR performance. Inspired by these methods, this study aims to extend the dimorphic systems to the MRGs research for improving the rheological properties.…”

“…magnetic nanofibers, nanowires and nanosheets) have been studied in the MR literature in the past. These experiments determined that dimorphic MR materials exhibit improved rheological properties and better stability [17][18][19][20][21]. Li et al [17] fabricated and tested a series of bimodal particle MRE samples with different particle sizes of 50 and 5 μm.…”

Magnetorheology of Bimodal Fluids in the Single–Multidomain Limit

“…In view of the work by Foister (1997), most of the following literature in this field concerned non-Brownian suspensions with σ S ≈ 1 μm and, therefore, σ L /σ S ≈ 10. Most of these works provided similar observations to Foister (1997) with bimodal suspensions giving place to larger yield stresses than monomodal suspensions composed of either the small or the large particles. − Although the observed off-state viscosity reduction is well understood in terms of particle packing characteristics, the on-state yield stress enhancement is still not well understood. Bearing in mind that the effect of relative particle sizes on the magnetostatic force magnitude cannot explain the enhancement in the on-state yield stress in bimodal suspensions, one may think that the use of bimodal suspensions would result in more efficiently packed aggregates which are therefore stronger and promote a larger yield stress [e.g., Dodbiba et al (2008)].…”