Study of Methyl Orange Effect on the Optical and Electrical Properties of Polystyrene (PS)
Dr. Nahida J.Hameed , Karrar M. Ali

The present work was concerned with study of the methyl orange(MO) dye concentration effect on the optical properties ,and electrical properties of polystyrene(PS). The samples were casted as films from the homopolymer(PS) stated above and the Dye/PS(MO/PS)composites at (3.44,6.7,and 12.5%) concentration. These prepared polymer systems were evaluated spectrophotometically. It was found increasing in absorption spectra with increasing of the dye concentration in Dye/PS composites above, which was attributed to the increasing in localized states. The results proved that the best absorption was of (12.5%MO/PS), and of the lowest energy gap was (3.15eV),The optical constant (α,k,n, εr, and εi)for the homopolymer (PS) , (Dye/PS) composites, and hybrid composites at different concentration were investigated at(λc ,300nm). It was seen that there was nonlinear relationship between the optical constants and the concentration ratio, which was attributed to their incompatibility. These results were confirmed with optical micrographs. The (FTIR) spectra showed shifting, appearance ,and disappearance of new band, which was attributed to change in tacticity, geometry in the structure ,and overlapping of polymer composites band involved. The results proved that there was nonlinear relationship between the carrier concentration, mobility, fast increase in the (12.5%MO/PS, and became of order(10- 6 ). The increase in the conductivity with dye concentration was attributed to increase of the localized states in the energy gap.
Keywords: MO/PS, Optical Properties, Electrical Properties.
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