Abstract Entropy convergence is the experimental observation that the hydration entropies of families of non-polar solutes cross one another and converge at a distinct temperature above the boiling point of water. Entropy convergence has subsequently received significant theoretical and molecular simulation interest to interpret its molecular origin. Classic scaled particle theory has enjoyed success in describing entropy convergence for cavity-like, hard sphere solutes in water despite the fact it only considers water's equation-of-state and effective hard sphere diameter while neglecting liquid state inter-molecular correlations. This stands in difference to traditional interpretations of the hydrophobic effect that invoke water's three-dimensional structure when describing aqueous solutions of non-polar moieties. Here we investigate the origins of entropy convergence in classic scaled particle theory. We demonstrate convergence results from the theory's unphysical prediction that the surface tension of the solvent against a hard, flat interface exhibits a maximum as a function of temperature, indicative of a surface entropy that changes sign from negative to positive values with increasing temperature. In addition, we find that classic scaled particle theory can predict convergence like behavior in an organic liquid for which the phenomenon is unexpected.

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对溶剂化熵收敛的尺度粒子理论预测的评估

摘要 熵收敛是非极性溶质族的水合熵相互交叉并在高于水沸点的明显温度下收敛的实验观察。熵收敛随后受到了重要的理论和分子模拟兴趣，以解释其分子起源。经典比例粒子理论在描述水中空腔状硬球溶质的熵收敛方面取得了成功，尽管它只考虑了水的状态方程和有效硬球直径，而忽略了液态分子间相关性。这与在描述非极性部分的水溶液时调用水的三维结构的疏水效应的传统解释不同。在这里，我们研究了经典尺度粒子理论中熵收敛的起源。我们证明了理论的非物理预测的收敛结果，即溶剂对坚硬平坦界面的表面张力表现出作为温度函数的最大值，表明表面熵随着温度的升高而从负值变为正值。此外，我们发现经典的尺度粒子理论可以预测有机液体中的收敛行为，而这种现象是出乎意料的。指示表面熵随着温度的升高从负值变为正值。此外，我们发现经典的尺度粒子理论可以预测有机液体中的收敛行为，而这种现象是出乎意料的。指示表面熵随着温度的升高从负值变为正值。此外，我们发现经典的尺度粒子理论可以预测有机液体中的收敛行为，而这种现象是出乎意料的。