Frequency and temperature-dependent impedance spectroscopy of PVA/PEG polymer blend film

In this work, polymer blend films based on polyvinyl alcohol (PVA)/poly(ethylene glycol) (PEG) were prepared by solution casting technique. X-ray diffraction (XRD) analysis was performed to investigate the structural details of the polymer blend. XRD pattern confirms the polycrystalline nature of the films. Sandwich structures of the type Ag-PVA/PEG-Ag were formed to study the dielectric and conduction properties in the frequency range 300 Hz-3 MHz and at different temperatures varying from 298 K to 420 K. Experimental results show that both dielectric constant (epsilon') and dielectric loss (epsilon '') values were strong functions of frequency and temperature. The AC conductivity (sigma(AC)) was found to obey the power law A omega(s) and correlated barrier hopping as the conduction mechanism. The imaginary part of electric modulus shows peak shifting corresponding to relaxation mechanisms. Electric modulus study was also found to support the dielectric permittivity data.