A Local-Composition Model for the Prediction of Mixture Dielectric Constants

作者：Liu Jiangping; Wilding W Vincent; Rowley Richard L^*

来源：Journal of Chemical and Engineering Data, 2011, 56(5): 2430-2437.

DOI：10.1021/je200007x

A local composition model is developed for mixture dielectric constants based on the nonrandom two-liquid (NRTL) model commonly used for correlating activity coefficients in vapor-liquid equilibrium (VLE) data regression. In this model the NRTL local compositions, which represent an effective local molecular structure, are the counterpart of the Kirkwood factor g, which in dielectric constant theory characterizes local molecular orientations and their effect on the static dielectric constant. The resultant model requires values for the pure-component dielectric constant and binary NRTL model parameters available from VLE data compilations or predicted from the universal functional activity coefficient model (UNIFAC). It is predictive in that no mixture dielectric constant data are used and there are no adjustable parameters. Predictions made on 16 binary and six ternary systems at various compositions and temperatures compare favorably with extant correlations that require experimental values to fit an adjustable parameter in the mixing rule and are significantly improved over values predicted by Oster's equation that also has no adjustable parameters.

• 出版日期2011-5