Stabilized density gradient theory algorithm for modeling interfacial properties of pure and mixed systems

详细信息    查看全文

• 作者：Xiaoqun Mu^a ; Florian Frank^b ; Faruk O. Alpak^c ; Walter G. Chapman^a ; ^{wgchap@rice.edu}
• 关键词：Density gradient theory ; Stabilized algorithm ; Interfacial properties ; Surface tension ; PC-SAFT EoS
• 刊名：Fluid Phase Equilibria
• 出版年：2017
• 出版时间：15 March 2017
• 年：2017
• 卷：435
• 期：Complete
• 页码：118-130
• 全文大小：1874 K
• 卷排序：435

文摘

Density gradient theory (DGT) allows fast and accurate determination of surface tension and density profile through a phase interface. Several algorithms have been developed to apply this theory in practical calculations. While the conventional algorithm requires a reference substance of the system, a modified “stabilized density gradient theory” (SDGT) algorithm is introduced in our work to solve DGT equations for multiphase pure and mixed systems. This algorithm makes it possible to calculate interfacial properties accurately at any domain size larger than the interface thickness without choosing a reference substance or assuming the functional form of the density profile. As part of DGT inputs, the perturbed chain statistical associating fluid theory (PC-SAFT) equation of state (EoS) was employed with the SDGT algorithm. PC-SAFT has excellent performance in predicting liquid phase properties as well as phase behaviors. The SDGT algorithm with the PC-SAFT EoS was tested and compared with experimental data for several systems. Numerical stability analyses were also included in each calculation to verify the reliability of this approach for future applications.