Thermodynamic properties and contact angles of CTAB and SDS in acetone–water mixtures at different temperatures

Abstract

The thermodynamic properties of sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) in neat water and acetone–water mixtures were studied by measuring the conductivity at 298.15, 308.15, 318.15 and 323.15 K. The critical micelle concentration (CMC), degree of ionization (α), standard Gibbs free energy of micellization (ΔGmo), standard entropy of micellization (ΔSmo), standard heat of micellization (ΔHmo), the heat capacity of micellization (ΔmCPo) and free energy of transfer (ΔGtranso) were evaluated from conductivity data. The contact angles (CAs) were measured using a drop shape analyzer (DSA-25E). The correlation of ΔGmowith solvent parameters and the solvophobic parameter was explored.