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本研究采用了吉布斯系综蒙特卡洛方法(GEMC)对苯-噻吩-NMP三元体系在101.33 k Pa、4个温度点下的汽液平衡性质进行模拟计算。采用Tra PPE-EH力场模拟苯分子和噻吩分子,用OPLS-AA力场模拟NMP分子。得到的模拟结果与实验值吻合良好,证明了Tra PPE-EH力场以及OPLS-AA力场可以共同用于三元体系汽液平衡的预测,具有兼容性。对平衡液相的径向分布函数(RDF)的分析表明,由于NMP的加入,苯和噻吩的相互作用减弱,同时平衡液相中NMP与噻吩的相互作用强于NMP与苯的相互作用,整体表现为苯和噻吩的相对挥发度的增大。模拟结果也证明了几何平均以及算数平均混合规则在预测性质相近的原子的相互作用时精度接近,可以混用。
In this study, Gibbs Method Monte Carlo (GEMC) was used to simulate the vapor-liquid equilibrium of benzene-thiophene-NMP ternary system at 101.33 k Pa and 4 temperature points. Tra PPE-EH force field was used to simulate benzene and thiophene molecules, and NMP molecules were modeled by OPLS-AA force field. The simulation results obtained are in good agreement with the experimental ones. It is proved that the Tra PPE-EH force field and the OPLS-AA force field can be used together to predict the vapor-liquid equilibrium of the ternary system and has the compatibility. The analysis of the radial distribution function (RDF) of the equilibrium liquid phase shows that the interaction between benzene and thiophene is weakened due to the addition of NMP, while the interaction between NMP and thiophene in the equilibrium liquid phase is stronger than that between NMP and benzene. The performance of benzene and thiophene relative volatility increases. The simulation results also demonstrate that the geometric averaging and the arithmetic mean-mixing rule are close to each other in predicting the interactions of atoms of similar nature and can be mixed.