THE BEHAVIOR OF PENTANE, HEXANE, AND HEPTANE ON WATER
THE BEHAVIOR OF PENTANE, HEXANE, AND HEPTANE ON WATER
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DOI：
10.1016/0021-9797(80)90575-5
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发表时间：
1980-01-01
影响因子：
9.9
通讯作者：
JAMESON, GJ
中科院分区：
文献类型：
--
作者：
DELCERRO, C;JAMESON, GJ
已经发现，当时的烷烃正戊烷、正己烷和正庚烷放在水中时不会扩散。只要汽相中含有适当的碳氢化合物，正庚烷和正己烷就会形成圆形浮动透镜。正戊烷的行为更为复杂。似乎形成了液体戊烷岛，以相对较厚的均匀层平衡漂浮。根据实验结果，对用宏观Lifshitz理论预测烷烃/水体系范德华相互作用能的模型进行了验证。最符合观测数据的模型是包含所有可用光谱数据的模型，因此，包含整个光谱范围的贡献似乎是必不可少的。使用这个模型，哈梅克常数→在极限中被计算为厚度l⩽0；对于当时的烷烃5和lt；n AWA 16来说，这些常数都是正数，这表明应该形成所有厚度的透镜。而薄膜的化学势随L的增大而变化，并通过极小值。这些曲线被解释为表明透镜应该与分子比例的层形成平衡；中间厚度是不可能的。
It has been found that then-alkanes pentane, hexane, and heptane do not spread when placed on water. Provided the vapor phase is saturated with the appropriate hydrocarbon, heptane and hexane form circular floating lenses. The behavior of pentane is more complex. It appears that liquid pentane islands are formed, floating in equilibrium with relatively thick uniform layers. Models for predicting the van der Waals interaction energy forn-alkane/water systems by macroscopic Lifshitz theory are examined in the light of the experimental results. The model which appears best to fit the observations is that which includes all the available spectroscopic data, and it therefore appears essential to include contributions over the whole spectral range. Using this model, Hamaker constantsAWOAare calculated in the limit as the thicknessl→ 0; these are positive for all then-alkanes 5 < n ⩽ 16, suggesting that lenses should form for all thicknesses. However, the chemical potential of the film changes sign with increasingl, and passes through a minimum. The curves are interpreted to indicate that lenses should form in equilibrium with layers of molecular proportions; intermediate thicknesses are precluded.