Dynamic polarizability of rotating particles in electrorheological fluids

dc.creatorXiao, J. J.
dc.creatorHuang, J. P.
dc.creatorYu, K. W.
dc.date2008-03-20
dc.date.accessioned2026-07-07T09:41:28Z
dc.date.available2026-07-07T09:41:28Z
dc.descriptionA rotating particle in electrorheological (ER) fluid leads to a displacement of its polarization charges on the surface which relax towards the external applied field ${\bf E}_0$, resulting in a steady-state polarization at an angle with respect to ${\bf E}_0$. This dynamic effect has shown to affect the ER fluids properties dramatically. In this paper, we develop a dynamic effective medium theory (EMT) for a system containing rotating particles of finite volume fraction. This is a generalization of established EMT to account for the interactions between many rotating particles. While the theory is valid for three dimensions, the results in a special two dimensional configuration show that the system exhibits an off-diagonal polarization response, in addition to a diagonal polarization response, which resembles the classic Hall effect. The diagonal response monotonically decreases with an increasing rotational speed, whereas the off-diagonal response exhibits a maximum at a reduced rotational angular velocity $ω_0$ comparing to the case of isolated rotating particles. This implies a way of measurement on the interacting relaxation time. The dependencies of the diagonal and off-diagonal responses on various factors, such as $ω_0$, the volume fraction, and the dielectric contrast, are discussed.
dc.description6 pages, 4 figures, accepted to J. Phys. Chem. B
dc.identifierhttps://arxiv.org/abs/0803.2923
dc.identifierhttp://arxiv.org/abs/0803.2923
dc.identifierJ. Phys. Chem. B 112, 6767 (2008)
dc.identifierdoi:10.1021/jp8008223
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/161841
dc.subjectChemical Physics
dc.subjectMaterials Science
dc.subjectSoft Condensed Matter
dc.subjectClassical Physics
dc.titleDynamic polarizability of rotating particles in electrorheological fluids
dc.typetext

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