Effect of AgNO3 filling and UV-irradiation on the structure and morphology of PVA films

Polyvinyl alcohol films, with various AgNO3 filler mass fractions ( less than or equal to 5%), were prepared. The structural and morphological variations, due to filling and UV-irradiation. were investigated using the following techniques: differential scanning calorimetry (DSC), UV/VIS optical absorption spectroscopy, X-ray diffraction and scanning electron microscopy (SEM). Two different crystalline phases (one is due to the PVA matrix and the other is attributed to the PVA-Ag+ chelates) were detected besides the PVA amorphous phase, for the non-irradiated and the UV-irradiated (for 4 and 6 h) films. The PVA-Ag+ chelates disappeared at 2h UV-irradiation. It is implied that the structural morphology changes vastly due to the changes in filling level and/or UV-irradiation time. The observed morphological patterns were discussed. (C) 1999 Elsevier Science Ltd. All rights reserved.