Structural, thermal and optical behavior of laser irradiation-induced PVA–PEG–Ag nanocomposites

Polyvinyl alcohol−polyethylene glycol−silver (PVA–PEG–Ag) nanocomposites were prepared by adding Ag nanoparticles with 5 wt.% to the (PVA–PEG) blend. The films of 0.05 mm thickness were prepared by the casting method. Samples from these films were irradiated with infrared (IR) laser fluences ranging from 1.7 to 15 J/cm2. The effect of IR laser radiation on the structural properties of PVA–PEG–Ag has been investigated using X-ray diffraction and Fourier transform infrared spectroscopy. The results indicate that the crosslinking dominates due to laser exposure at the fluence range 1.7–15 J/cm2, reducing the ordering character of the nanocomposite samples. Also, the variation of transition temperatures with the laser fluence has been determined using differential thermal analysis. The nanocomposite thermograms were characterized by the appearance of an endothermic peak due to melting, and were found to be dependent on the laser fluence. In addition, the color changes due to laser irradiation were computed using the transmission data. It is found that the color difference is largely dependent on the proportions of the red color component.