Optical properties of gelatin/TGS composites

Abstract

Films of pure Gelatin and five Gelatin samples doped with the ferroelectric material triglycine sulphate (TGS) at various concentrations of 2, 4, 6, 8 and 10 wt. %TGS by weight have been prepared using the solvent-casting technique.Ultraviolet-visible (UV-vis) absorption spectra were measured in the range 190-900nm. The UV-Visible spectra show some shift in the absorption edge indicating change in optical band gap energy. The optical transitions were found mainly to be indirect allowed transitions and the optical band gaps (Eopt) were determined. Measuring the absorbance, transmittance and reflectance of Gelatin, TGS and their composites permitted the calculation of the refractive index (n). The refractive index dispersion curve of composite films obeys the single-effective oscillator model (Wemple-DiDomenico model).