LAUSR

Abstract Dyeing is one of the most important processes in the textile industries which require optimum binding of dye with the fabrics. In the binding phenomenon of dye with the fabrics, surfactants play a significant role. The presence of different auxiliaries modifies the dye-surfactant interaction which can influence the binding of dye with the fabrics. Herein, we studied the interaction of crystal violet (CV) dye with a cationic surfactant, dodecyltrimethylammonium bromide (DTAB) conductometrically in absence and presence of electrolytes (NaBr, Na2SO4, and Na3PO4). The critical micelle concentration (cmc) of DTAB was found to dwindle with the boost of concentration of CV. The cmc of CV + DTAB mixtures were monotonically increased with the increase of temperature. The presence of electrolytes facilitates the micellization of CV + DTAB mixture. The values of counterion binding were found to be augmented with the augmentation of temperature in aqueous and NaBr media while the opposite trend was observed in Na2SO4 and Na3PO4 media. The Gibbs free energy of micellization ( Δ G m 0 ) were found to be negative in all cases. The enthalpy ( Δ H m 0 ) and entropy ( Δ S m 0 ) of micellization were negative and positive in aqueous, NaBr, and Na2SO4 media while both values were positive in Na3PO4 medium. The enthalpy–entropy compensation parameters suggest that the most stable micelle of CV + DTAB is formed in Na2SO4 medium.