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A Surface Tension Model for Liquid Mixtures Based on NRTL Equation

LI Chunxi; WANG Wenchuan   

  1. College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029,
  • Received:1900-01-01 Revised:1900-01-01 Online:2001-03-28 Published:2001-03-28
  • Contact: LI Chunxi

Abstract: A new equation for predicting surface tension is proposed based on the thermodynamic
definition of surface tension and the expression of the Gibbs free energy of the system.
Using the NRTL equation to represent the excess Gibbs free energy, a two-parameter surface
tension equation is derived. The feasibility of the new equation has been tested in terms
of 124 binary and 16 multicomponent systems(13-ternary and 3-quaternary) with absolute
relative deviations of 0.59% and 1.55% respectively. This model is also predictive for the
temperature dependence of surface tension of liquid mixtures. It is shown that, with good
accuracy, this equation is simple and reliable for practical use.

Key words: model, surface tension, liquid mixtures, Gibbs free energy, NRTL equation