Abstract
•The aggregation behavior of SDS in acid yellow dye with additives is investigated.•The cmc values are dependent on the additive’s composition and temperature.•The aggregation of AY + SDS mixture is obtained to be spontaneous for all systems.•Hydrophobic and electrostatic interactions between AY and SDS are noticed.•MD simulation displays that SDS micelle is more stable in NaCl than water/ethanol media.
Herein, we report the micellization behavior of the mixture of sodium dodecyl sulfate (SDS), and acid yellow (AY) dye in water, water + ethanol, and water + NaCl media. The degree of interaction between SDS and AY has been assessed quantitatively from the estimated values of critical micelle concentration (cmc). Three cmc values were observed for the AY + SDS systems at each temperature and solvents utilized, which exhibit a reversed U-shaped variation with respect to the change of temperature in aqueous/NaCl solution while increased monotonically in ethanolic medium almost in all cases. The extent of micellization was found to be disfavored in presence of AY dye. The micellization was also found to be disfavored up to 15% ethanol and favored in the addition of electrolyte species. The values of counterion binding were found to be temperature dependent. The Gibbs free energy (ΔGmo), which was found negative, reveal a spontaneous micellization of AY + SDS system. The other thermodynamic parameters, like enthalpy (ΔHmo) and entropy (ΔSmo) of micellization along with different transfer energies, were also assessed to have an insight on the mode of interaction of surfactant and dye assemblies. The molecular level interaction between SDS and AY has been unveiled by Molecular Dynamics (MD) simulation and exhibits good agreement with experimental results.