Thermo-Acoustic Behavior of Brij-30 in Alcoholic Aqueous Medium: Modulation by Inorganic Salts

The study explores the thermo-acoustic behaviour of the non-ionic surfactant Brij-30 in alcoholic aqueous medium in the presence of selected inorganic salts. Ultrasonic velocity and density measurements were carried out at varying concentrations and temperatures to evaluate key thermo-acoustical parameters such as adiabatic compressibility, intermolecular free length, acoustic impedance, and molar sound velocity. The influence of inorganic salts on micellization, solvent–solute interactions, and structural modifications within the mixed solvent system was systematically investigated. Results indicate that the presence of salts significantly alters the aggregation behavior of Brij-30, thereby modifying acoustic and thermodynamic properties. The observed variations provide insights into ion–surfactant–solvent interactions, highlighting the role of electrolytes in tuning micellar dynamics and structural organization in alcohol–water mixtures. Such findings are of importance in understanding surfactant systems relevant to colloidal chemistry, drug delivery, and formulation science.