Diffusion of some dyes in aqueous polymer solutions

Abstract

AbstractThe diffusion of both Direct Blue 76 and acid orange dyes in aqueous dilute polymer solutions was studied using the capillary method. The polymer systems studied included dilute solutions of carboxymethyl cellulose, polyethylene oxide and polyacrylamide. It was found that the diffusion coefficients of the two dyestuffs in carboxymethyl cellulose solutions are higher than that in pure water, while in polyacrylamide solutions the values of the coefficients are lower than that in pure water. In case of polyethylene oxide solutions, the diffusion coefficient of Direct Blue 76 was found to be lower than that in pure water, whereas that of acid orange was found to be higher than that in pure water.The diffusion coefficients of both dyes were found to decrease with increasing polymer concentration in the case of polyethylene oxide and polyacrylamide, whereas in the case of carboxymethyl cellulose the diffusion coefficients increased with polymer concentration.With change of temperature, the diffusion coefficients of both dyes in the three polymer solutions were found to obey the Arrhenius equation. The activation energy for diffusion of the two dyes was calculated in pure water, as well as in the different polymer solutions.