الفهرس 
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Abstract
Polymeric materials are of interest in scientific and technological research, because they can be tailored to meet specific requirement for a verity of applications, this is mainly due to their light weight, good mechanical strength, and optical properties.from which, Poly Vinyl Alcohol (PVA) is one of the most important polymeric materials, because it has many applications in industry and is of relatively low cost in manufacture It is well documented that electrical and optical properties of polymers can be improved to a desired limit through suitable doping. In this concern, and since Ag+ is a fast conducting ion in a number of crystalline and amorphous materials, its incorporation within a polymeric system may be expected to enhance its electrical and optical properties In the present study the PVA/Ag nanocomposite with different contents of inorganic phase of (2, 3, 4, 5, 6, 7, and 8) wt% were prepared by reduction of Ag+ ions in PVA solution using gamma irradiation with different dose of (15, 25, 50, 75, 100) kGy. The Ag particle size was found to be around 14.0 nm based on the UV-Vis spectroscopy and Dynamic Light Scattering (DLS) measurements. Also, the structural studies of the synthesized PVA/Ag nanocomposites have been carried out through FTIR, and XRD studies. Further, the dependence of the optical and electrical properties of PVA on the concentration of the embedded nano-Ag was reported. As well, the effects of γ- irradiation have been studied applying UV-Vis spectroscopy and electrical characteristics measurements, respectively. The changes in the optical band gap value and room temperature dc conduction behaviour of undoped and Ag doped PVA films have been studied. The value of optical band gap has been found to be reduced from (4.6 eV) for un-doped PVA up to (3.0 eV) on doping (4 wt%) nano-Ag in PVA. This decrease in optical band gap and observed increase in conduction can be correlated to the formation of the charge transfer complexes within the polymer network on dispersing nano-Ag in it. In addition, γ- irradiation of PVA/Ag samples leads to the formation of Ag nanoparticles, and chain scission and cross-linking in the polymer and consequently improved optical and electrical properties.