Abstract
An equation proposed to describe the diffusion behaviour of reactive dyes was applied to the systems of cellophane rolls and two reactive dyes of Procion M type:
(I) (Semi-infinite medium) Where C is the concentration of active dye at time t at distance x, C* the surface concentration of active dye, K the reaction constant of active dye and D the diffusion coefficient of active dye.
In order to determine the diffusion coefficient (D) and the reaction constant (K), eq. (I) was integrated to fit the experimental data by graphical asessment.
Effects of pH, dye concentration and dyeing temperature on D and K are discussed. Activation energy of the system is also calculated.
The results obtained are as follows:
(a) With increase in pH, the diffusion coefficient has a tendency to increase and the reaction constant increases.
(b) The diffusion coefficient and the reaction constant are independent of the dye concentration.
(c) As dyeing temperature rises, both the diffusion coefficient and the reaction constant increase, while the surface concentration decreases.
