STUDY ON ELECTRORHEOLOGICAL PROPERTIES OF SEMICONDUCTING POLYANILINE-BASED SUSPENSIONS

Electrorheological (ER) fluids composed of a dispersing medium with a low dielectric constant and polyaniline particles, deprotonated with a mmonia or sodium hydroxide at different concentrations for 24 h were s tudied. The effects of dielectric constant, conductivity and volume fr action of the polyaniline particles, the kind of dispersing medium, ad dition of surfactant, as well as the electric field strength and tempe rature on the ER properties of the ER fluids were investigated. The re sults showed that a moisture-insensitive, highly ER-active fluid can b e obtained from chlorinated paraffin oil and polyaniline particles dep rotonated with ammonia water at certain pH values and exhibited a stat ic yield stress >10 kPa and current density <40 mu A cm(-2) at 2.8 kV mm(-1) DC electric field.