关键词: 密度泛函理论, 表面张力, 密度剖面, 非极性混合流体

Abstract: The density functional theory was applied to study the surface properties of binary non-polar fluid mixtures. In this work, the molecule was considered as the sphere chain, and the interaction between segments in different molecules was expressed as the hard-core Yukawa potential. A reasonable long range correction was adopted to avoid the error by truncation in the potential. The perturbation theory was used to establish the equation of state for the phase equilibrium calculation. The parameters ε/k, d and m_s for pure fluids were regressed from the experimental data of the vapor-liquid phase equilibria, and such parameters could lead to good prediction for surface tension. The vapour-liquid phase equilibria and the surface properties of 6 binary fluid mixtures (including surface tension and density profile) at different temperaturs were regressed or predicted with the mixing parameter k_ij. The results indicated that the calculated values for surface tension agreed well with the experimental data.The calculated local density profiles showed that enrichment of the component on the surface of binary fluid mixtures might happen.

Key words: 密度泛函理论, 表面张力, 密度剖面, 非极性混合流体