Solvent effects on the dielectric dispersion of poly(vinyl pyrrolidone)-poly(ethylene glycol) blends

Abstract

The complex relative dielectric function \( \varepsilon *{\left( \omega \right)} = \varepsilon \prime - j\varepsilon \prime \prime \), loss tangent \( \tan \delta = {\varepsilon \prime \prime } \mathord{\left/ {\vphantom {{\varepsilon \prime \prime } {\varepsilon \prime }}} \right. \kern-\nulldelimiterspace} {\varepsilon \prime } \), complex electric modulus \( M*{\left( \omega \right)} = M\prime + jM\prime \prime \) and alternating current electrical conductivity dispersion behaviour of liquid poly(vinyl pyrrolidone)-poly(ethylene glycol) (PVP–PEG) blends in water, ethyl alcohol and 1,4–dioxane solvent over the entire volume mixture concentration range has been investigated in the frequency range of 20 Hz to 1 MHz at 25 °C. The PVP–PEG blends show the dielectric dispersion corresponding to the micro-Brownian motion of the PVP chain in the upper frequency region, whereas in the lower frequency region, dielectric dispersion is due to ionic conduction and electrode polarization phenomena. Results show that the conductivity values of these blends in water and dioxane can be monitored with the change in the solvent concentration, whereas it has a small variation with ethyl alcohol concentration. The comparative dielectric dispersion shape study confirms that the chain dynamics of polymers blend is influenced by heterogeneous interactions and solvent polar strength.