Spectrophotometric Investigation of the Solubilization and Thermodynamics of Eriochrome Blue Black R in Cationic, Nonionic and Zwitterionic Surfactant Systems

.This study investigates the interactions between the anionic dye Eriochrome Blue Black R and three types of surfactants (cationic CTAB, nonionic TX-100, and zwitterionic CAPB) using UV-visible spectrophotometry. The solubilization efficiency and thermodynamics of dye-surfactant interactions was evaluated by determining binding constants and partition coefficients KX for each surfactant systems, and it was found that CTAB exhibits the highest solubilization efficiency due to strong electrostatic attraction. The thermodynamic analysis confirms that these dye-surfactant interactions are spontaneous, with electrostatic and hydrophobic forces playing a key role. The nonionic TX-100 and zwitterionic CAPB demonstrated comparatively lower dye-binding capabilities. These findings provide valuable insights into dye-surfactant systems, which are relevant to applications in wastewater treatment, dye removal, and formulation chemistry.