Study of optical properties of potassium permanganate ($\hbox {KMnO}_{4}$) doped poly(methylmethacrylate) (PMMA) composite films

Abstract

We have developed films of pure polymethylmethacrylate (PMMA) (0.5, 1, 2 and 5%) and potassium permanganate $(\hbox {KMnO}_{4})$-doped PMMA composite films of thickness ($\sim 100\, \upmu \hbox {m}$) using the solution-cast technique. To identify the possible change that happen to the PMMA films due to doping, the optical properties were investigated for different concentrations of $\hbox {KMnO}_{4}$ by recording the absorbance (A) and transmittance ($T\%$) spectra of these films using UV–Vis spectrophotometer in the wavelength range of 300–1100 nm. From the data obtained from the optical parameters viz. absorption coefficient ($\alpha$), extinction coefficient ($\kappa$), finesse coefficient (F), refractive index ($\eta$), real and imaginary parts of dielectric constant ($\varepsilon _{\mathrm{r}}$ and $\varepsilon _{\mathrm{i}})$ and optical conductivity ($\sigma$) were calculated for the prepared films. The indirect optical band gap for the pure and the doped-PMMA films were also estimated.