Study of Micellization of Aqueous Sodium Dodecylbenzene Sulfonate in Alcohol Solutions

Apparent molar volumes, Φv and isentropic compressibilities, κ_s of monohydric long chain alcohols, nonan-1-ol and decan-1-ol in aqueous solution of anionic surfactant, sodium dodecylbenzene sulfonate (SDBS) have been calculated from experimental densities, ρ and speed of sound, u, measured at 298.15, 303.15, and 308.15 K. The standard partial molar volumes, Φ^ov have been calculated for rationalizing various interactions in the studied solutions. The critical micelle concentration (cmc), of SDBS in dilute aqueous solution of octan-1-ol, at various temperatures was determined from conductance measurements in the range of ∼0.009 to 0.0734 mol%. Thermodynamic parameters of micellization i.e. standard enthalpy change (ΔH⁰_m), standard entropy change (ΔS⁰_m) and standard Gibbs free energy change (ΔG⁰_m) have been evaluated from temperature dependence of cmc. Further, ¹H and ¹³C NMR chemical shift measurements in micelle solutions containing nonan-1-ol and decan-1-ol have also been made and the results are presented and discussed.