In this work, the magnetorheological properties of suspensions micron-sized iron particles dispersed in magnetite ferrofluids were studied. With aim, flow steady-state regime investigated using a commercial magnetorheometer with parallel-plate measuring cell. The effect both and concentration on magnitude yield stress was studied for broad range magnetic fields. addition, experimental values compared predictions from chain model. purpose obtained by means finite element calculations....

This work reports a detailed study on the shear magnetorheology of suspensions magnetic microfibers. The steady-state regime was investigated using controlled-stress rheometer for different concentrations particles and under presence broad range applied fields (up to 512kAm−1). results were compared with those obtained conventional magnetorheological fluids (suspensions microspheres). It found that fibers show an enhanced effect. We proposed existence field-dependent solid friction between...

The inclusion of magnetic nanoparticles into biopolymer matrixes enables the preparation field-responsive engineered tissues. Here we describe a synthetic route to prepare biocompatible core–shell nanostructures consisting polymeric core and shell, which are used for this purpose. We show that using architecture is doubly advantageous. First, gravitational settling nanocomposites slower because reduction composite average density connected light polymer core. Second, response can be tuned by...

This series of two papers is devoted to the effect organic dye (methylene blue, MB; or methyl orange, MO) adsorption on surface either bare citrate-coated magnetic iron oxide nanoparticles (IONPs) their primary agglomeration (in absence an applied field) and secondary field-induced agglomeration. The present paper (Part I) focused physicochemical mechanisms adsorption-induced IONPs. Dye oppositely charged IONPs found be mostly promoted by electrostatic interactions very sensitive pH ionic...

The inclusion of magnetic nanoparticles (MNP) in a hydrogel matrix to produce hydrogels has broadened the scope these materials biomedical research. Embedded MNP offer possibility modulate physical properties remotely and on demand by applying an external field. Moreover, they enable permanent changes mechanical hydrogel, as well alterations micro- macroporosity its three-dimensional (3D) structure, with associated potential induce anisotropy. In this work, behavior biocompatible...

Insects, renowned for their abundant and renewable biomass, stand at the forefront of biomimicry-inspired research offer promising alternatives chitin chitosan production considering mounting environmental concerns inherent limitations conventional sources. This comprehensive review provides a meticulous exploration current state insect-derived chitosan, focusing on sources, methods, characterization, physical chemical properties, emerging biomedical applications. Abundant insect sources...

This paper reports the first predictions of yield stress suspensions non-Brownian magnetic fibers in presence uniform fields. The quasistatic regime shear deformation (before flow onset) suspension is studied. Four different structures fiber are considered—column, zigzag, three-dimensional stochastic and near-planar structures—and attributed to failure given structure at a critical strain. main contributions found come from restoring torque acting on each solid friction between fibers....

In this work, we report the synthesis under presence of external magnetic fields two types microfibers: (i) cobalt wires; and (ii) rigid filaments chemically linked iron microspheres. Optical microscopy scanning electron (SEM) were used for characterizing their shape size. The effect field intensity, mixing frequency reagent concentration on final size fibers was investigated. particles also characterized by means energy dispersive X-ray spectroscopy (EDX). magnetization curves both wires...

This article summarizes the work carried out in development of hydrodynamic lubricated journal bearings with magnetic fluids. Two different fluids have been analyzed: one is ferrofluid from FERROTEC APG s10n and other magnetorheological (MR) fluid LORD Corp., MRF122-2ED. Theoretical analysis has numerical solutions Reynolds equation, based on apparent viscosity modulation for Bingham model MR fluid. To validate this model, test bench designed, manufactured, set up, where preliminary results...

Fiber-like particles are mostly used as basic components of electrorheological and magnetorheological suspensions because their lower sedimentation rate higher yield stress. The theoretical approach the stress mainly rests on interaction between two spherical particles. We analyze interactions fibers, taking into account contribution friction fibers. Comparing experimental results to model we conclude that it is not possible clearly assess what part due in increase which, other hand, can be...

Magnetic hydrogels are becoming increasingly in demand for technical and biomedical applications, especially tissue engineering purposes. Among them, alginate-based magnetic emerge as one of the preferred formulations, due to abundance, low cost, biocompatibility alginate polymers. However, their relatively slow gelation kinetics provokes strong particle settling, resulting nonhomogeneous hydrogels. Here, we study prepared by a novel two-step protocol that allows obtaining macroscopically...

The research work reported in this article is focused on the use of magnetic fluids as active lubricant for improving performance hybrid journal bearings, with application to high-precision machine tools. Prototype design was optimized following numerical computation Reynolds equation and computational fluid dynamics calculations, both cases Herschel–Bulkley model magnetorheological fluid. This (LORD Corp. MRF 122-2ED) experimentally characterized detail. improvement hydrodynamic effect...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation S. Bounoua, E. Lemaire, J. Férec, G. Ausias, P. Kuzhir; Shear-thinning in concentrated rigid fiber suspensions: Aggregation induced by adhesive interactions. Rheol. 1 November 2016; 60 (6): 1279–1300. https://doi.org/10.1122/1.4965431 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Modesto T. López-López, Pavel Kuzhir, Juan D. G. Durán, Georges Bossis; Normal stresses in a shear flow of magnetorheological suspensions: Viscoelastic versus Maxwell stresses. J. Rheol. 1 September 2010; 54 (5): 1119–1136. https://doi.org/10.1122/1.3479043 Download citation file: Ris (Zotero) Reference Manager...

In this work, we have studied field-induced aggregation and magnetic separation—realized in a microfluidic channel equipped with single magnetizable micropillar—of multicore iron oxide nanoparticles (IONPs) also called “nanoflowers” of an average size 27 ± 4 nm covered by either citrate or polyethylene (PEG) monolayer having thickness 0.2–1 3.4–7.8 nm, respectively. The the adsorbed molecular layer is shown to strongly affect dipolar coupling parameter because thicker layers result larger...

This work deals with the magnetic field-induced static yield stress of magnetorheological (MR) suspensions concentration near limit maximum-packing fraction. With this aim, homogeneous iron microparticles 50 vol.% were prepared, and their measured as a function applied field. In view failure existing models to predict, on basis realistic hypotheses, values highly concentrated MR suspensions, we developed new model. Our model considers that field application induces body-centered tetragonal...

This work is focused on the characterization and magnetorheological (MR) study of MR fluids composed iron particles sepiolite fibers, used as a thickening agent. The aimed at (a) understanding effect addition response (b) finding an appropriate formulation allowing good sedimentation stability keeping relatively low off-state viscosity providing enhanced effect. In presence applied magnetic field, composite fluid exhibits yielding behavior with progressive enhancement field-induced static...

The present paper is focused on the theoretical and experimental study of kinetics field-induced aggregation magnetic nanoparticles a size range 20-100 nm. Our results demonstrate that (a) in polydisperse suspensions, largest particles could play role centers nucleation for smaller during earliest heterogeneous stage; (b) an intermediate stage aggregate growth (due to diffusion migration individual towards aggregates) weakly influenced by field strength, at least high supersaturation; (c)...

When a micron-sized magnetizable particle is introduced into suspension of nanosized magnetic particles, the nanoparticles accumulate around microparticle and form thick anisotropic clouds extended in direction applied field. This phenomenon promotes colloidal stabilization bimodal suspensions allows efficient separation used bioanalysis water purification. In present work, size shape nanoparticle under simultaneous action an external uniform field flow have been studied detail. experiments,...