Abstract

Using the lattice gas model, we consider a unified description of three types of two-phase interfaces (vapor–liquid, solid–vapor, and solid–liquid) in the vapor–liquid meniscus system inside a size-limited pore in the form of a rectangular parallelepiped. Pore walls are considered to be undeformable. They form the external field for a stratifying fluid. The state of coexisting “vapor in a pore” and “fluid in a pore” phases satisfy the equality of chemical potentials, which excludes the appearance of metastable states. We present a calculation procedure for molecular distributions and shapes of menisci in the isolated pore considered, which enables the equally accurate calculation of molecular distributions in heterogeneous distributed models of transition regions of three interfaces. The calculation procedure of the surface tension (ST) on three types of two-phase interfaces of the liquid–vapor–solid wall system is elaborated. The procedure of introducing a contact angle in the liquid–vapor–solid pore wall system is described using adsorbate molecular distributions in the considered pore. It is obtained that, as the system decreases, the critical temperature lowers, while the pressure, chemical potential, and ST values of a fluid with a solid increase. Liquid–vapor ST decreases with decreasing area of pore bases (i.e., with pore narrowing), and when the pore height increases, liquid–vapor ST increases. The dependences of the liquid–vapor transition region width and the contact angle of the vapor–liquid meniscus are derived as functions on the pore width and the pore wall potential.

中文翻译：

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汽-液-固系统中有限系统体积对表面张力的影响

摘要

使用晶格气体模型，我们考虑统一描述气液弯月面系统中气液弯月面系统中三种类型的两相界面（气-液、固-气和固-液），其形式为一个长方体。孔壁被认为是不可变形的。它们形成分层流体的外部场。“气孔”和“气孔”相共存的状态满足化学势相等，排除了亚稳态的出现。我们提出了所考虑的孤立孔中弯月面的分子分布和形状的计算程序，它能够在三个界面的过渡区域的异质分布模型中同样准确地计算分子分布。详细阐述了液-气-固壁系统三种两相界面表面张力（ST）的计算过程。使用所考虑的孔中的吸附物分子分布描述了在液-气-固孔壁系统中引入接触角的过程。得到，随着体系的减小，临界温度降低，而固体流体的压力、化学势和ST值增加。液-汽ST随着孔底面积的减小（即随着孔变窄）而降低，当孔高度增加时，液-汽ST增加。液-汽过渡区宽度和汽-液弯液面接触角的相关性被推导出为孔宽度和孔壁电位的函数。