Abstract

Numerous experimental data are available on contact angles. However, the majority of them concern sessile droplets, although bubbles are more interesting from the point of view of colloid science, because a sessile bubble is distinguished by the existence of an equilibrium thin liquid film at a gas–solid interface. This paper presents the totality of modern thermodynamic equations necessary for describing the contact angle of a bubble of an arbitrary size. However, in view of their complexity, specific relationships are derived and analyzed for small although macroscopic bubbles. The dependences of a bubble contact angle on the temperature, pressure in a liquid, composition of a liquid phase, and roughness of a solid surface are considered. In the case of a pure liquid, when a gaseous phase consists of its vapor, the obtained relations are of significance for the cavitation theory. The study as a whole has a framework character, and so only the general basic results are presented. Their detailing is possible in combination with experimental data.

中文翻译：

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无泡气泡接触角的热力学

摘要

关于接触角有大量的实验数据。然而，尽管从胶体科学的角度来看气泡更有趣，但大多数气泡都与无固定液滴有关，因为无固定气泡的特征是在气固界面处存在平衡的液态薄膜。本文介绍了描述任意大小气泡接触角所必需的现代热力学方程式。但是，鉴于它们的复杂性，尽管存在宏观气泡，但仍会导出并分析特定关系，以获取较小的气泡。考虑气泡接触角对温度，液体中的压力，液相的组成以及固体表面的粗糙度的依赖性。对于纯液体，当气相由其蒸气组成时，获得的关系对空化理论具有重要意义。这项研究总体上具有框架特征，因此仅介绍了一般的基本结果。结合实验数据可以进行详细说明。