Internal rotations in dielectric suspensions

A. Cebers¹ - E. Lemaire² - L. Lobry²

¹ Institute of Physics, University of Latvia,
² Salaspils-1, LV-2169, Latvia
³ Laboratoire de Physique de la Mati?re Condens?e (CNRS U.M.R. 6622), Parc Valrose, 06108 Nice Cedex 2, France

Abstract
A review of some models of dielectric suspensions accounting for the internal rotations due to the finite Maxwell relaxation time is given. We present the consequences of the particles rotation on the rheological and electrical behavior of a suspension submitted to a DC field. We show that this spontaneous rotation leads to a negative apparent viscosity and to an augmentation of the effective conductivity of the suspension above a critical electric field. For ellipsoidal particles we show that the possible rotation of the particles around their long axis may stabilize the transversal orientation of the fibers in the field. Figs 14, Refs 12.