Effect of the U.V. Irradiation on the Aqueous Solution of Dye (i.e. Cresol Purple)

Enas A Almadani; Hamad M Adress

Abstract

This study aimed to estimate the effect of the U.V. irradiation on the aqueous solution of cresol purple. Then study the effect of the activation energy of each electron transfere on the absorbance and λmax values. The absorbance and λmax values of the selective λmax solutions were chanced in most solutions, where the U.V radiation gave different values at different irradiation periods, most of solution gave low values of absorbance comparing with the original standard solutions of the indicator and the λmax were changed, most of solution showed a relative changes in λmax values and gave high absorbance values comparing with the original standard solutions of dye. The study attributed those changes in absorbance are due to the effecting to U.V irradiations on the type of electronic transition of π → π* and πn → π* which they were attributed to the original structure of the indicator used. The spectra of absorption of the unirradiated and irradiated solutions were measured in the wavelength from 250 to 650 nm according to λmax of the original solution. The λmax values were measured by studying the λmax change at different time periods (5, 10, 15, 20 min) of U.V irradiance. To calculate the transition energy values were used the equation (ET = h C NA/λ).

Abstract

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