Influence of γ irradiation on the optical and colour characteristics of the polyvinyl alcohol/polyvinyl pyrrolidone blend film

Abstract

With the aid of a solution casting technique, we created a blended film made of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP). Gamma doses (5-40 kGy) were applied to samples of the synthetic PVA/PVP film. UV spectroscopy and the CIE colour alterations procedure were used to investigate the impact of the γ dose on the optical features of the synthesized film. The direct optical bandgap (Eg), affected by cross-linking, destroyed the crystalline structure and formed the amorphous regions, dropped from 2.53 to -2.08 eV with the increase in γ dose to 40 kGy. Thus, the PVA/PVP film's compact structure increases. The films displayed a transition which was directly allowed as the ϵ'' vs. hν plots revealed Eg approximately equal to the values derived from Tauc's equation. The colour variances, between the unaltered and irradiated films, were also identified. Significant colour differences could be seen in the pure PVA/PVP film.

Keywords

• Radiation
• blend
• UV − vis spectra
• colour alternations
• polymers