COLE-COLE ANALYSIS ON DIELECTRIC SPECTRA OF ELECTRORHEOLOGICAL SUSPENSIONS

Abstract

Along with rheological properties, dielectric spectra of the ER fluids were found to provide additional information on both analyzing their electrical polarization properties and interpreting their flow behavior. Dielectric properties of three different material systems such as spherical-monodisperse polymer microspheres (PAPMMA) consisting of a poly(methyl methacrylate) (PMMA) core and a polyaniline (PANI) shell, single-doped and mesoporous-doped TiO 2 system and copper phthalocyanine-doped mesoporous TiO 2 suspensions based ER fluid were analyzed via dielectric spectra of permittivity and loss factor as a function of the frequency, and Cole-Cole plots. Polarizability which is defined as a difference of dielectric constant at both zero frequency and infinite frequency was found to be a proper parameter to understand a better ER fluid. Using the Cole-Cole plot, we were not only able to fit the dielectric spectra, but also to deduce the achievable polarizability by explaining the higher ER performance of the ER fluids.