Dispersive parameters of oxidized PVA-PVP blend films

Authors: GOPUTTA VEENA, BLAISE LOBO

Abstract: Oxidized (ox) polyvinyl alcohol (PVA)-polyvinyl pyrrolidone (PVP) blend films were prepared by solution casting technique, with doping levels of the oxidizer, potassium permanganate (KMnO₄) , varying from 0.01 up to 4.70 weight percent (wt.%). Optical (UV-Vis) spectral measurements in the wavelength range varying from 190 nm to 1000 nm were used to extract the band gap information and to calculate various optical parameters of the ox-PVA-PVP blend films. The electronic transitions on absorption of photons of suitable energy are of indirect allowed type. The corresponding optical band gap (E_g) has been determined. Optical dispersion parameters for ox-PVA-PVP films were determined using the Wemple and Didomenico method. Complex dielectric constants, relaxation time (τ) , dissipation factor (tan δ) , ratio of charge carrier concentration to effective mass (N/m*), plasma frequency (ω_p) , average oscillator wavelength (λ_o) , oscillator strength (S_o) , optical conductivity (σ) , and optical momenta of spectra (M_-1 and M_-3) were determined.

Keywords: Oxidized polymer, PVA-PVP blend, optical analysis, potassium permanganate, UV-Vis spectra

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