THERMODYNAMICS OF CAVITY FORMATION IN WATER - A MOLECULAR-DYNAMICS STUDY
THERMODYNAMICS OF CAVITY FORMATION IN WATER - A MOLECULAR-DYNAMICS STUDY
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水中空腔形成的热力学 - 分子动力学研究
DOI：
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发表时间：
1982
期刊：
影响因子：
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通讯作者：
J. R. Haak
中科院分区：
文献类型：
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作者：
J. Postma;H. Berendsen;J. R. Haak
与疏水溶质在水中的溶剂化作用有关的热力学量可以通过应用标度粒子理论来近似。关键的量是空穴形成的吉布斯自由能。已经进行了一系列的六个分子动力学模拟水，包括各种大小的排斥腔。使用微扰统计力学，自由能已被推导出作为腔半径的函数高达0.32 nm（0.32 nm的水氧的腔中心的方法）。自由能同意以及从缩放粒子理论的预测和实验的表面张力预测在5%以内。水分子相对于腔的径向分布已被确定为五个腔的大小;对于一个尺寸（水氧的接近半径为0.3 nm）的取向分布和在水化壳中的停留时间分布已被确定。
Thermodynamic quantities related to the solvation of hydrophobic solutes in water can be approximated by the application of scaled-particle theory. The crucial quantity is the Gibbs free energy of cavity formation. A series of six molecular-dynamics simulations of water including repulsive cavities of various sizes has been carried out. Using perturbation statistical mechanics, the free energy has been derived as a function of cavity radius up to 0.32 nm (0.32 nm approach of water oxygens to the cavity centre). The free energy agrees well with predictions from scaled-particle theory and the experimental surface tension is predicted to within 5%. The radial distribution of water molecules with respect to the cavity has been determined for five cavity sizes; for one size (radius of approach of water oxygens of 0.3 nm) the orientational distribution and the residence-time distribution in the hydration shells has been determined.