Low-frequency dielectric spectroscopy of polyampholyte gels

The dielectric spectra of crosslinked polymers based on sodium polymethacrylate, poly(diallyldimethylammonium chloride), and their copolymers with alternating and statistical sequences of monomer units were obtained in the frequency range from 10 Hz to 10 kHz and temperature range from 20 to 80°C. Abnormally high values of the dielectric constant Ε' (about 104) were observed for poly(diallyldimethylammonium chloride). This is associated with formation of strongly polarized hydrated ion-containing clusters. An analysis of the temperature dependences of Ε' for all samples showed that the dielectric response of the copolymer with statistical distribution of monomer units is largely determined by the response of diallyldimethylammonium chloride monomer blocks. The calculated parameters of the power law of the dielectric response indicate that, for poly(diallyldimethylammonium chloride) and the copolymer with the statistical distribution of monomers, the interaction of charge carriers occurs, whereas for other samples, the conduction is governed by ion drift.