الفهرس 
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Abstract
The study aims to introduce a new polymeric material with superior physical and chemical properties using pre synthesized nanometric silica obtained from sustainable source (rice husk). Transmission electron microscope image of synthesized silica nanoparticles shows a homogenous distribution of spherical nanoparticles with diameter ranged between 20-30 nm and their spectra was compared to that of pure reagent materials which observed to have nearly same functional groups while their x-ray diffraction pattern are similar to that found in literature. Synthesized nanparticles was examined by energy dispersive x-ray EDX which show the presence of some trace impurities beside the nanometric silica result from the constituent of plant result for preparation. PVC, PS and their 50/50 polymer blend was successfully prepared as a thin film using Tetrahydrofuran THF as a common solvent via casting technique. Other samples that contain nanometric silica in increasing content up to 30% wt/wt were also prepared and studied using different spectroscopic techniques. Xray diffraction pattern shows the amorphous nature of prepared virgin polymers and their blend and reveals also an increase in the amorphous nature result from increasing silica content which approve the distribution of silica within the polymeric matrix without any evidence for aggregation or accumulation of silica. Energy dispersive X-ray EDAX was performed for selected samples to ensure the percent of partner silica introduced during preparation process. FTIR result shows the maintenance of the function group of constituent polymer and their blend while change in their intensity combined with small shift in position were attributed to some type of interaction between constituent polymeric matrices and inorganic filler. UV/vis. optical absorption spectra was used to calculate the optical energy gap of studied materials using different transition model (direct allowed, indirect allowed, direct forbidden and indirect forbidden) that shows that the dominant transition is the indirect allowed type of transition and this result was correlated to the DC conductivity measurements. It was noticed also that electrical conductivity is a function in both silica content and temperature.