Comparative Analysis of Acid Red ۲۷ and Acid Yellow ۲۳ Solubilization in Micellar Media Enhanced with Ammonium Salt

This study examines how two anionic dyes, AR-۲۷ and AY-۲۳, behave when solubilized in micellar environments containing cetyltrimethylam-monium ammonium bromide (CTABr) enhanced with ammonium chloride (NH۴Cl). UV-Visible spectroscopy technique have been utilized quantitatively to explores the solubilization process, estimating factors like binding constant, 𝐾𝑏, partition coefficients (𝐾𝑥),  Gibbs energy of binding (Δ𝐺𝑏), and Gibbs energy of partition, (Δ𝐺𝑝). In addition, electrical conductivity at different temperatures have been employed to determine the critical micelle concentration (CMC) of the surfactant and to calculate thermodynamic parameters such as enthalpy (Δ𝐻𝑚), entropy (Δ𝑆𝑚), and Gibbs energy of micellization (Δ𝐺𝑚) in the presence of the dyes and NH۴Cl. Notably, the study reveals that AR-۲۷ exhibits greater favorability and spontaneity in solubilization and binding compared to AY-۲۳ when NH۴Cl is introduced. Experimental findings suggest that the solubilization process is characterized by exothermicity, spontaneity, and enthalpy-driven mechanisms. This study emphasizes the significance of comprehending the interactions that exist between dyes and surfactants, stresses the necessity of optimizing the NH۴Cl concentration and, in the end, and provides insightful information for effectively incorporating dyes into micellar solutions.

Keywords:

AR-۲۷ , AY-۲۳ , Micellization , Entropy-driven , Spontaneous , Solubilization