Abstract:

Dyeing kinetics and thermodynamic of sorghum husk colorants on wool fabric were investigated in order to explain of the dyeing mechanisms and provide theoretical basis for optimization of the dyeing conditions. The results showed that the adsorption process of sorghum husk colorants on wool fabrics could be well described by the pseudo-second-order kinetic model. The dyeing rate constant，the half-dyeing time and diffusion coefficient increased with the increasing dyeing temperature from 80 °C to 100°C. The adsorption isotherm was identified to be a Langmuir type, which belonged to monolayer adsorption. The dye adsorbed at equilibrium and adsorption capacity increased with the increasing dyeing temperature from 80 to 100°C. The values of entropy change and enthalpy change of dyeingtion process were negative.

Key words: sorhgum husk colorant, wool fabric, adsorption kinetics, adsorption thermodynamics