Acoustic studies on anionic surfactant with sugars in aqueous media at different temperatures

Abstract

The density (d) and speed of sound (v) for an anionic surfactant sodium dodecyl sulphate (SDS) in the concentration range (1-14) mmol∙dm^-3 in aqueous solutions of sugars (fructose and maltose) at 293.15, 298.15, 303.15, 308.15 and 313.15 K, have been measured. The experimental data have been used to estimate various derived acoustical parameters such as intermolecular free length (L_f), relative association (RA), specific acoustic impedance (z), molar sound number (U), molar volume (V_m), Wada’s constant (W) and Rao’s constant (R_m), and some excess properties like excess molar volume (V_m^E), excess isentropic compressibility (k^E_s) and excess free length (L^E_f).L_f values decrease but at the same time RA values increase with the concentration of sodium dodecyl sulphate. Comparatively, L_f values are found to be higher in aqueous fructose than maltose solutions. The variation of all these parameters have been interpreted in terms of various intermolecular interactions such as strong, weak, charge transfer, complex formation and hydrogen bonding interactions occurring in the ternary system. A good to excellent correlation between a given parameter and concentration of SDS/sugars is observed for all the studied systems.