Measurement and modeling of surface tension of binary mixtures containing N,N-dimethylcyclohexylamine and alcohols

Abstract

In this work, the surface tension of the six binary systems containing N, N-dimethylcyclohexylamine (DMCHA) and alcohol (1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol or 1-decanol) was measured over the whole DMCHA concentration at the temperatures of (293.15 to 323.15) K and 101 kPa. Based on the experimental data, surface tension deviation (Δσ) was calculated. The values are positive for all the binary mixtures and decreased with chain length of alcohols. The results were correlated using different models. The surface tensions were fitted by Fu-Li-Wang (FLW) model with stand deviations (S) less than 0.122. The surface tension deviations were well fitted by Myers-Scott (MS) and Redlich-Kister (RK) equations with S ≤ 0.052. Additionally, according to the relationship of surface tension and temperature, the thermodynamic properties, surface enthalpy (Hγ) and surface entropy (Sγ), were also estimated. All the above results were further analyzed and discussed in terms of temperature, composition and chain length of alcohol.