Structure of electrorheological fluids: A dielectric study of chain formation

Horváth, Barnabás; Szalai, István

doi:10.1103/physreve.86.061403

Cited by 23 publications

(27 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[42] the static and dynamic yield stress has been investigated and in both cases smooth curves as a function of the external magnetic field were found until column formation was completed. We finally mention an experiment on the dielectric investigation of chain formation in ERFs [43]. A continuous change in dielectric permittivity as a function of electric field strength was observed.…”

Section: B Influence Of Spatial Modulationsmentioning

confidence: 85%

Macroscopic two-fluid effects in magnetorheological fluids

et al. 2020

View full text Add to dashboard Cite

We investigate macroscopic two-fluid effects in magnetorheological fluids generalizing a one-fluid model studied before. In the bulk of the paper we use a model in which the carrier fluid, with density ρ 1 , moves with velocity v 1 , while the magnetic component (density ρ 2) and, therefore, the magnetization and the magneticfield-induced relaxing strain field move with velocity v 2. In the framework of macroscopic dynamics we find, in particular, reversible dynamic and dissipative cross-coupling terms between the magnetization and the velocity difference. Experiments to detect some of these cross-coupling terms are suggested. We also compare the results of the two-fluid model presented here with two-fluid models available for electrorheological fluids. In two appendices we discuss the simplifying assumptions made to arrive at the model used in this paper and we also outline how to detect potential deviations from this model.

show abstract

Section: B Influence Of Spatial Modulationsmentioning

confidence: 85%

Macroscopic two-fluid effects in magnetorheological fluids

et al. 2020

View full text Add to dashboard Cite

show abstract

“…How the reduced parameters are related to real-life physical parameters can be computed independently (see Section 5). [38,39].…”

Section: Scaling and Reduced Unitsmentioning

confidence: 99%

Brownian dynamics simulation of chain formation in electrorheological fluids

Fertig¹,

Boda²,

Szalai³

2020

Hung. J. Ind. Chem.

View full text Add to dashboard Cite

Brownian dynamics (BD) simulations based on a novel Langevin integrator algorithm are used to simulate the dynamics of chain formation in electrorheological (ER) fluids that are non-conducting solid particles suspended in a liquid that has a dielectric constant different from that of the ER particles. An external electric field induces polarization charge distributions on the spheres' surfaces that can be modeled as point dipoles in the centers of the spheres. The interaction of these aligned dipoles leads to formation of chains and other aggregates in the ER fluid. In this work, we introduce our methodology and report results for various quantities characterizing the structure of the ER system as obtained with BD simulations. These quantities include the potential energy, diffusion constant, average chain length, chain length distributions, and pair correlation functions. Their behavior as a function of time is presented as the electric field is switched on. The properties of the ER fluid change considerably making this system a potential basic material of many applications.

show abstract

“…The dynamic magnetic response of the nanofibers was determined by a special magnetic susceptibility measurement method, which is the magnetic counterpart of the dielectric response-time measurement technique. 18 The sample was placed inside a solenoid, which is the frequency-determining element of an LC oscillator. The frequency was measured by an HP 53310A modulation domain analyzer.…”

Section: Magnetic Measurementsmentioning

confidence: 99%

Biotemplated synthesis of magnetic filaments

et al. 2017

View full text Add to dashboard Cite

With the aim of creating one-dimensional magnetic nanostructures, we genetically engineered flagellar filaments produced by Salmonella bacteria to display iron- or magnetite-binding sites, and used the mutant filaments as templates for both nucleation and attachment of the magnetic iron oxide magnetite. Although nucleation from solution and attachment of nanoparticles to a pre-existing surface are two different processes, non-classical crystal nucleation pathways have been increasingly recognized in biological systems, and in many cases nucleation and particle attachment cannot be clearly distinguished. In this study we tested the magnetite-nucleating ability of four types of mutant flagella previously shown to be efficient binders of magnetite nanoparticles, and we used two other mutant flagella that were engineered to periodically display known iron-binding oligopeptides on their surfaces. All mutant filaments were demonstrated to be efficient as templates for the synthesis of one-dimensional magnetic nanostructures under ambient conditions. Both approaches resulted in similar final products, with randomly oriented magnetite nanoparticles partially covering the filamentous biological templates. In an external magnetic field, the viscosity of a suspension of the produced magnetic filaments showed a twofold increase relative to the control sample. The results of magnetic susceptibility measurements were also consistent with the magnetic nanoparticles occurring in linear structures. Our study demonstrates that biological templating can be used to produce one-dimensional magnetic nanostructures under benign conditions, and that modified flagellar filaments can be used for creating model systems in which crystal nucleation from solution can be experimentally studied.

show abstract

Structure of electrorheological fluids: A dielectric study of chain formation

Cited by 23 publications

References 20 publications

Macroscopic two-fluid effects in magnetorheological fluids

Macroscopic two-fluid effects in magnetorheological fluids

Brownian dynamics simulation of chain formation in electrorheological fluids

Biotemplated synthesis of magnetic filaments

Contact Info

Product

Resources

About