Optical, structure and thermal investigation of the effect of gamma radiation in CPVC/Ag and CPVC/Pd nanocomposites membrane

The updated Nanostructure materials and nano-technological tools are predicted to enable the synthesis polymer-inorganic composites to manufacture higher qualified membranes possess attractive physical and chemical properties with high performed sensitivity and selectivity. In this study carboxylated poly (vinyl chloride) (CPVC), CPVC/silver and CPVC/palladium nanocomposites membranes were prepared. Samples from the CPVC/Ag and CPVC/Pd nanocomposites films were irradiated with gamma doses in the range 25-150kGy. The structural modifications in the gamma-irradiated nanocomposite samples have been studied as a function of dose using different characterization techniques such as X-ray diffraction XRD, UV spectroscopy, color difference studies, Thermogravimetric analysis TGA and scanning electron microscope SEM. The results indicate that the gamma irradiation in the dose range 50-150kGy led to a more compact structure of both CPVC/Ag and CPVC/Pd nanocomposite films, which resulted in an improvement in its thermal stability with an increase in the activation energy of thermal decomposition and amorphous phase. It is worth mentioned that the nano-palladium is more effective than nano-silver composite membranes in stabilizing the CPVC. In addition, the results of color difference measurements indicated that both the CPVC/Ag and CPVC/Pd nanocomposite films acquire color under gamma irradiation up to 150kGy, but the response of CPVC/Ag to color changes is higher. For this reason, the CPVC/Ag nanocomposite film was chosen to be a subject for the further study to investigate the effect of gamma irradiation on its optical and microscopic properties. it is found that the gamma irradiation reduces the optical energy gap that could be attributed to the increase in structural disorder of the irradiated CPVC/Ag nanocomposite due to crosslinking.