Acid dye diffusion in solvent-assisted dyeing

Rates of diffusion of Orange II into wool previously extracted with methanol and diethyl ether have been measured at 35°C and pH 7. 0 in the presence of a variety of organic solvents. In all cases studied, the presence of solvent decreases the rate of diffusion, which is found to be proportional to the total moles of solvent plus water in the fibre. The solvent can increase the uptake of this dye by wool if the wool is incompletely extracted.