Abstract
Polyvinyl alcohol (PVA) films doped with potassium iodide (KI) have been prepared by casting from their aqueous solutions. The structure of the doped samples was investigated using Fourier transform infrared spectroscopy. The addition of KI to PVA structure leads to form crosslinking as well as the increase of the amorphous ratio within the investigated sample. The optical measurements were recorded at room temperature in the range of 200-2500 nm. It was found that the optical energy gap of the investigated sample increases with increasing KI ratio. The effect of the addition increment of KI on the optical parameters of PVA has been investigated. Dielectric spectra of PVA doped with KI were studied in the temperature and the frequency ranges of 303-373 K and 100 Hz-5 MHz, respectively. The behavior of dielectric constant (epsilon(1)) and dielectric loss index (epsilon(2)) of PVA sample doped with KI exhibits good linearity with temperature. The obtained results suggest strongly the applicability of these materials in the temperature sensor applications.