Experiments and Simulations on the Magnetorheology of Magnetic Fluid Based on Fe₃O₄ Hollow Chains

Abstract

This work reports an experiment/simulation combination study on the magnetorheological (MR) mechanism of magnetic fluid based on Fe3O4 hollow chains. The decrease of shear stress versus the increasing magnetic field was observed in a dilute magnetic fluid. Hollow chains exhibited a higher MR effect than pure Fe3O4 hollow nanospheres under a small magnetic field. A modified particle level simulation method including the translational and rotational motion of chains was developed to comprehend the correlation between rheological properties and microstructures. Sloping cluster-like microstructures were formed under a weak external field (24 mT), while vertical column-like microstructures were observed under a strong field (240 mT). The decrease of shear stress was due to the strong reconstruction process of microstructures and the agglomeration of chains near the boundaries. The chain morphology increased the dip angle of microstructures and thus improved the MR effect under a weak field. This advantage made Fe3O4 hollow chains to be widely applied for small and low-power devices in the biomedical field. Dimensionless viscosity as a function of the Mason number was collapsed onto linear master curves. Magnetic fluid in Poiseuille flow in a microfluidic channel was also observed and simulated. A qualitative and quantitative correspondence between simulations and experiments was obtained.

Hysteresis in Two Dimensional Arrays of Magnetic Nanoparticles

“…MNPs also interact due to the long-ranged dipolar interaction [49]. We can calculate the dipolar interaction energy E dip in an assembly of MNPs as [50][51][52]]…”

Influence of the Hollowness and Size Distribution on the Magnetic Properties of Fe3O4 Nanospheres

“…Magnetic particles have been widely used in the biomedical field, as carriers, for environmental protection, for electromagnetic wave absorption, as batteries, and as magnetic fluids because of their magnetic properties, biological compatibility, chemical stability, and low toxicity. − To date, a series of magnetic particles, such as Fe–Co particles with higher saturation magnetization, has been developed. , However, the high density and cost of the magnetic particles has limited their wide application. Therefore, development of magnetic particles with low density and cost and high saturation magnetization has attracted considerable interest in materials science and engineering technology research. − …”

The Effect of Sr-CoFe2O4 Nanoparticles with Different Particles Sized as Additives in CIP-Based Magnetorheological Fluid

“…In the absence of a magnetic field, the viscosity along the shear rate in all MRF samples shows a relatively constant value and behaves like a Newtonian fluid. However, when a magnetic field is applied, the curve shows that the viscosity decreased as the shear rate increased and behaved like shear tinning [44]. On the other hand, the viscosity of the MRF showed an obvious increase as the Figure 8 shows the correlation between storage modulus and loss modulus against shear strain during oscillatory testing at a constant frequency of 6.28 rad/s.…”