Physical Characterization of Poly (vinyl ...

Polymeric films of pure poly (vinyl pyrrolidone) (PVP) and PVP/gelatin blend (60/40) containing various amounts of MgCl2 were prepared using a casting technique. The structural and related physical properties of the prepared films were studied using different techniques. The obtained data revealed that the addition of gelatin and magnesium chloride causes structural variation in the PVP network. The X-Ray diffraction (XRD) patterns reveal that the amorphous nature of the blend increases with the concentration of magnesium chloride. Complex formation was confirmed by XRD and FT-IR analysis. The DSC results indicate that the addition of both gelatin and magnesium chloride to PVP changes the thermal behavior, such as the glass transition temperature and thermal stability. The analysis of the UV-visible optical absorption shows the decrease in the optical band gap (Eg) as dopant concentration increase. The reduced values of the optical gap improve their optical response, which can be used as optical sensors. The direct current (DC) electrical resistivity studies revealed a linear temperature dependence of the hopping distance (Ro) for all doped films. The conduction mechanism discussed based on the phonon-assisted charge carrier inter-polaron hopping model. Moreover, the addition of both gelatin and MgCl2 gives rise to improve the electrical properties of PVP film. The optical and electrical results suggested the applicability of these materials in optical and/or electrical sensors.