Dyeing theory

Dyeing theory

Dyeing theory is concerned with how a given dye is taken up by a particular textile fibre. Two approaches are used to study the mechanism of dyeing insofar as the dyeing system is studied: at equilibrium (thermodynamics of dyeing) and before equilibrium is attained (kinetics of dyeing). The purpose of studying the thermodynamics of dye adsorption is to elucidate the mechanism by which dye adsorption occurs and, in addition, to provide a quantitative measure of the tendency of the dye to pass from the solution phase (i.e. the dyebath) to the fibre phase. The experimental determination of the diffusion coefficient of dyes within fibres is undertaken using especially stringent conditions demanded by the theoretical models employed. The two diffusional processes are described by Fick's laws of diffusion, the first law relating to both steady-state and non-steady state diffusion while the second law concerns only non-steady-state diffusion.