EFFECTS OF SHAPE AND SIZE OF DISPERSOID ON ELECTRORHEOLOGY

Abstract

The effects of shape and size of dispersoids on electrorheology were investigated. In order to study the effect of shape on electrorheology, three kinds of hydroxy-zinc complexes were used for dispersoids. Hydroxy-zinc complexes were Zn 5 (OH) 8 Cl 2 · H 2 O (1), Zn 5 (OH) 8( NO 3)2 · 2H 2 O (2), and Zn 5 (OH) 8( CH 3 COO )2 · 2H 2 O (3). Shapes of (1) and (2) are plate. The shape of (3) is rod. The ER fluid containing (3) showed the lowest permittivity and the lowest ER effect. The ER phenomena containing dispersoids with different shapes were independent of their shapes and were explained by their dielectric properties. Zinc oxides prepared by the heat treatment of (1), (2), and (3) were used for studying the effect of size on electrorheology. The particle size influenced their dielectric property and influenced their electrorheology. The dielectric properties were responsible for the ER effect.