Adsorption of Direct Dyes on Cotton: Kinetics of Dyeing from Finite Baths Based on New Information

Abstract

Adsorption time curves were determined for cotton fabric dyed with direct dyes under different conditions. A new simple method is described for kinetic analysis of adsorption time curves. Adsorption equilibria, specific rate constants, diffusion coef ficients, diffusion resistance, steady-state equilibrium constants, adsorbent capacities, finite bath exhaustions, activation energies, and reaction enthalpies were determined from the time curves. Specific rate constants and the diffusion coefficients correlated with the chemical structures of direct dyes (number of aromatic rings and ionizable sulfo groups).