The Interaction of Mass Diffusion and Chemical Reaction During Finishing and Dyeing of Textiles

Abstract

Mass transport rates of reactants within textile fibers can markedly affect the kinetic and mechanistic interpretation of observed reaction rates during finishing and dyeing of textiles. Simple criteria are presented which allow estimates to be made to show whether appreciable diffusion phenomena exist during these processes. These criteria are independent of any specific chemical reaction, but depend for a given textile substrate of given dimensions mainly on the rate of the reaction and the adsorption behavior and the diffusion coefficient of the chemical reagents. The theoretical basis of these criteria is explained with the aid of a simple diffusion-immobilization model. Computed graphs enable the magnitude of diffusion effects, to be easily determined from experimental data in the form of a diffusion factor η. Knowing η, the intrinsic reaction kinetics can then be determined. The usefulness of this procedure is discussed.