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Apparent molar volumes, Φv, and isentropic compressibilities, κ s , of the aqueous solutions of anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), have been derived from experimental densities, ρ, and speed of sound, u, data measured below 0.40 mol·kg−1 at T = (298.15, 303.15, 308.15, and 313.15) K using an Anton Paar densimeter (DSA-5000). Conductance measurements were also made for aqueous solutions of SDBS to obtain critical micelle concentration at the above temperatures. Apparent molar volumes and isentropic compressibilities of 1-pentanol and 1-hexanol dissolved in aqueous micellar solutions of SDBS were determined as a function of molalities of surfactant (0.05 and 0.1) mol·kg−1 and alcohols at T = (298.15 and 308.15) K. The standard partial molar volumes, Φo v, and transfer volume, Φo v (tr), have been calculated for rationalizing various interactions in the studied solutions. Viscosity measurements were made for the above-mentioned alcohols in aqueous solutions of SDBS to obtain relative viscosity and viscosity B-coefficient. The second transition of aqueous sodium dodecylbenzene sulfonate in the postmicellar region has been obtained. Proton NMR chemical shift measurements in micelle solutions containing 1-pentanol have also been made, the results of which support the conclusions drawn from thermodynamic measurements.

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Densities, ρ, speeds of sound, u, viscosities, η, and specific conductivities, κ, of mixtures of 1-pentanol or 1-hexanol with the anionic surfactant sodium dodecyl sulfate (SDS) have been measured at molalities between (0.05 and 0.10) mol·kg−1 and temperatures of (298.15 and 308.15) K. The apparent molar volumes, Φv, partial molar volumes, Φo v, transfer volume, Φo v(tr), isentropic compressibility, κs, relative viscosity, ηrel, viscosity A- and B-coefficients, free energies per mole of solvent, Δμ1 0#, and per mole of solute, Δμ2 0#, and limiting molar conductivity, Λ0 m, were calculated to permit speculation of the interactions prevailing in the studied aqueous surfactant−alcohol systems. The results were interpreted from the point of view of alcohol−surfactant−water interactions in these systems. Further, 1H NMR chemical shift measurements in micelle solutions containing 1-pentanol have also been carried out. The results obtained are compared with the conclusions drawn from the thermodynamic measurements.