Experiments and model for the surface tension of DEAE-PZ and DEAE-MEA aqueous solutions

Highlights: • The surface tensions of DEAE and amine-DEAE aqueous solutions were measured. • The experiments were modelled satisfactorily by using a thermodynamic equation. • MEA and PZ have close ability to decrease the solution surface tension. • The temperature dependence of the surface tension was illustrated. • The effects of the mass fractions of amines and DEAE were demonstrated. - Abstract: The surface tension (γ) of 2-diethylaminoethanol (DEAE), DEAE-monoethanolamine (MEA), and DEAE-piperazine (PZ) aqueous solutions was measured by using the BZY-1 surface tension meter. The temperature ranged from 303.2 K to 323.2 K. The mass fraction of DEAE, MEA and PZ respectively ranged from 0.30 to 0.50, 0.05 to 0.15 and 0.025 to 0.075. An equation was proposed to model the surface tension and the calculated results agreed well with the experiments. The effects of temperature and mass fraction of amines on the surface tension were demonstrated on the basis of experiments and calculations.