Kinetics of wool dyeing with acid dyes

Studies of the thermodynamics and kinetics of dyeing over the past 60-70 ye ars have not resulted in complete acceptance for one mechanism for the dyei ng process. Contrary to the two existing explanations of wool-dye isotherm data (the Gilbert-RideaI and Donnan theories), the uptake of the acid dye u sed in this study conforms to the law of mass action. In addition, although it has generally been accepted that the kinetics of wool dyeing is diffusi on controlled, the uptake rate of the acid dye used in this study can be mo deled by a second-order rate expression based on the formation of a protein -dye complex as the rate determining step. The mechanism developed from thi s study involves the dye and other anions present in the dye solution inter acting independently with the wool, rather than the dye displacing smaller anions in a strict ion exchange manner.