This work has been dedicated to modeling the vapor–liquid equilibria and surface tension of carboxylic acids + water mixtures at different temperatures. The Peng–Robinson equation of state with modified Huron–Vidal + Wilson mixing rule correctly models the vapor pressure and vapor mole fraction of these mixtures. The modified Huron–Vidal mixing rule was better than quadratic mixing rule to model the phase equilibria properties for the mixtures studied in this work. The parachor method and linear gradient theory were used to model the surface tension of these mixtures. Finally, a new symmetric parameter dependent on the liquid molar fraction and temperature was necessary to correctly adjust the surface tension of the carboxylic acids + water mixtures using linear gradient theory. The surface tension results obtained in this work are better than those published so far.

中文翻译：

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使用 Peng-Robinson 状态方程和梯度理论模拟羧酸 + 水混合物的汽液平衡和表面张力

这项工作致力于模拟不同温度下羧酸 + 水混合物的气液平衡和表面张力。带有修正的 Huron-Vidal + Wilson 混合规则的 Peng-Robinson 状态方程正确地模拟了这些混合物的蒸气压和蒸气摩尔分数。改进的 Huron-Vidal 混合规则比二次混合规则更好地模拟本工作中研究的混合物的相平衡特性。Parachor 方法和线性梯度理论被用来模拟这些混合物的表面张力。最后，依赖于液体摩尔分数和温度的新对称参数对于使用线性梯度理论正确调整羧酸 + 水混合物的表面张力是必要的。