Department of Chemistry, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China.
J Chem Phys. 2013 Sep 28;139(12):124103. doi: 10.1063/1.4821599.
We develop an improved renormalization group (RG) approach incorporating the critical vapor-liquid equilibrium asymmetry. In order to treat the critical asymmetry of vapor-liquid equilibrium, the integral measure is introduced in the Landau-Ginzbug partition function to achieve a crossover between the local order parameter in Ising model and the density of fluid systems. In the implementation of the improved RG approach, we relate the integral measure with the inhomogeneous density distribution of a fluid system and combine the developed method with SAFT-VR (statistical associating fluid theory of variable range) equation of state. The method is applied to various fluid systems including square-well fluid, square-well dimer fluid and real fluids such as methane (CH4), ethane (C2H6), trifluorotrichloroethane (C2F3Cl3), and sulfur hexafluoride (SF6). The descriptions of vapor-liquid equilibria provided by the developed method are in excellent agreement with simulation and experimental data. Furthermore, the improved method predicts accurate and qualitatively correct behavior of coexistence diameter near the critical point and produces the non-classical 3D Ising criticality.
我们开发了一种改进的重整化群（RG）方法，该方法纳入了临界汽液平衡不对称性。为了处理汽液平衡的临界不对称性，在朗道-金兹堡配分函数中引入了积分度量，以实现伊辛模型中的局部序参量与流体系统密度之间的交叉。在改进的 RG 方法的实施中，我们将积分度量与流体系统的不均匀密度分布联系起来，并将开发的方法与 SAFT-VR（变程统计关联流体理论）状态方程结合起来。该方法应用于各种流体系统，包括方阱流体、方阱二聚体流体以及实际流体，如甲烷（CH4）、乙烷（C2H6）、三氟三氯乙烷（C2F3Cl3）和六氟化硫（SF6）。所开发方法提供的汽液平衡描述与模拟和实验数据非常吻合。此外，改进的方法还预测了临界点附近共存直径的准确和定性正确的行为，并产生了非经典的 3D 伊辛临界性。
