Abstract
Three-phase polymer electrolyte nanocomposite composed of polyvinyl-alcohol (PVA), manganese(II) chloride (MnCl2), and multiwall carbon nanotubes (MWCNTs) were prepared using the cast techniques. Impedance spectroscopy was used to investigate the AC electrical conductivity (sigma(ac)) of two- and three-phase samples with different weight ratios of multiwall carbon nanotubes (MWCNTs) over a wide frequency range and at various fixed temperatures (30 degrees C to 120 degrees C). The frequency-dependent nature of sigma(ac) was seen to follow Jonscher's power law. The redistribution of accumulated charges was used to explain the change in the pre-exponent (n) and the constant (A) after the percolation threshold. As the temperature approached the glass transition temperature, the mobility of ions and polymeric chains also played an important role in this change. The Correlated Barrier Hopping (CBH) model was considered as the most predicted model for the samples at temperatures below 100 degrees C. However, the Quantum Mechanical Tunneling (QMT) model was predicted to be the most prevalent conduction model for temperatures greater than 100 degrees C. The values of the activation energy calculated from both Z" and M" are mostly close. Equivalent circuits were used to analyze the impedance spectra of the two- and three-phase samples. An attempt was made to explain the impedance behavior of the samples through the elements participating in the equivalent circuits.