Surface tension of binary mixtures composed of N, N-dimethylcyclohexylamine and alcohols at different temperatures

Abstract

Surface tension (γ) for five binary mixtures containing N, N-dimethylcyclohexylamine (DMCA) and alcohol, ethanol, n-propanol, iso-propanol, n-butanol or iso-butanol were measured over the whole range of composition at 0.1 MPa and different temperatures ranging from (288.15 to 308.15) K. From the experimental data, the surface tension deviations (δγ) for the binary mixtures were calculated. The δγ values are positive for all the studied systems and increase with the decreasing of alky chain length of alcohol. For the mixture containing the branched alkyl alcohol, the increase is significant compared with the equivalent molecules with straight chains. According to temperature dependence of surface tension, the thermodynamic parameters, surface enthalpy (Hγ) and surface entropy (Sγ) were also estimated and further discussed.