聚合物-二氧化碳混合物的密度泛函理论：受扰链 SAFT 方法。

Density-functional theory for polymer-carbon dioxide mixtures: a perturbed-chain SAFT approach.

机构信息

Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.

出版信息

J Chem Phys. 2012 Aug 7;137(5):054902. doi: 10.1063/1.4742346.

Abstract

We propose a density-functional theory (DFT) describing inhomogeneous polymer-carbon dioxide mixtures based on a perturbed-chain statistical associating fluid theory equation of state (PC-SAFT EOS). The weight density functions from fundamental measure theory are used to extend the bulk excess Helmholtz free energy to the inhomogeneous case. The additional long-range dispersion contributions are included using a mean-field approach. We apply our DFT to the interfacial properties of polystyrene-CO(2) and poly(methyl methacrylate) CO(2) systems. Calculated values for both solubility and interfacial tension are in good agreement with experimental data. In comparison with our earlier DFT based on the Peng-Robinson-SAFT EOS, the current DFT produces quantitatively superior agreement with experimental data and is free of the unphysical behavior at high pressures (>35 MPa) in the earlier theory.

摘要

我们提出了一种基于受扰链统计关联流体理论状态方程（PC-SAFT EOS）的密度泛函理论（DFT），用于描述不均匀的聚合物-二氧化碳混合物。我们使用从基本测量理论中得到的权重密度函数将本体过剩亥姆霍兹自由能扩展到非均匀情况。通过平均场方法包含额外的长程色散贡献。我们将我们的 DFT 应用于聚苯乙烯-CO(2)和聚（甲基丙烯酸甲酯）-CO(2)系统的界面性质。计算得到的溶解度和界面张力值与实验数据吻合良好。与我们之前基于 Peng-Robinson-SAFT EOS 的 DFT 相比，当前的 DFT 与实验数据的一致性更好，并且没有早期理论中在高压（>35 MPa）下的非物理行为。