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 (\(\Delta G_{\text{m}}^{\text{o}}\)), standard entropy of micellization (\(\Delta S_{\text{m}}^{\text{o}}\)), standard heat of micellization (\(\Delta H_{\text{m}}^{\text{o}}\)), the heat capacity of micellization (\(\Delta _{\text{m}} C_{\text{P}}^{\text{o}} )\) and free energy of transfer (\(\Delta G_{\text{trans}}^{\text{o}}\)) were evaluated from conductivity data. The contact angles (CAs) were measured using a drop shape analyzer (DSA-25E). The correlation of \(\Delta G_{\text{m}}^{\text{o}}\)with solvent parameters and the solvophobic parameter was explored.