Surface tension measurement and modeling for ternary aqueous solutions of N, N-diethylethanolamine + 2-amino-2-methyl-1-propanol/piperazine + water at T = (293.15 to 318.15) K

The surface tensions of ternary aqueous mixtures composed of N, N-diethylethanolamine (DEEA) (1), 2-amino-2-methyl-1-propanol (AMP) or piperazine (PZ) (2) and H₂O (3) was measured at temperatures ranging from (293.15 to 318.15) K and 101 kPa. The systems with mass fractions of w₁ = (0.20, 0.25, 0.30 and 0.35) DEEA, and w₂ = (0.02 to 0.10) AMP/PZ were investigated. According to the experimental data, the surface tension deviation (Δγ) was obtained and the values were negative under the studied condition. Δγ values were fitted using a polynomial based on the Scatchard model with the average absolute deviation (AAD) ＜ 0.099 mN∙m⁻¹ and the average relative deviations (ARD) ＜ 0.31 %. Moreover, the surface tension values were fitted using Fu-Li-Wang (FLW) and the extended Wilson models. The results revealed that both models can well correlate the surface tension as a function of temperature and composition. FLW model exhibited better fitting results with smaller AAD of less than 0.24 mN∙m⁻¹ and ARD less than 0.68 %, respectively. Additionally, surface enthalpy (H^γ) and surface entropy (S^γ) were estimated based on the temperature dependence of surface tension.