Dispersive parameters of oxidized PVA-PVP blend films

Abstract

Oxidized (ox) polyvinyl alcohol (PVA)-polyvinyl pyrrolidone (PVP) blend films were prepared by solutioncasting technique, with doping levels of the oxidizer, potassium permanganate (KMnO4) , varying from 0.01 up to 4.70weight percent (wt.%). Optical (UV-Vis) spectral measurements in the wavelength range varying from 190 nm to 1000nm were used to extract the band gap information and to calculate various optical parameters of the ox-PVA-PVPblend films. The electronic transitions on absorption of photons of suitable energy are of indirect allowed type. Thecorresponding optical band gap (Eg) has been determined. Optical dispersion parameters for ox-PVA-PVP films weredetermined using the Wemple and Didomenico method. Complex dielectric constants, relaxation time ( ) , dissipationfactor (tan ) , ratio of charge carrier concentration to effective mass (N/m) , plasma frequency (!p) , average oscillatorwavelength (o) , oscillator strength (So) , optical conductivity () , and optical momenta of spectra (M􀀀1 and M􀀀3)were determined.