Abstract

Three types of two-phase interfaces (vapor–liquid, solid–vapor, and solid–liquid) are considered in the “vapor and liquid meniscus” system inside a slitlike pore with rough walls. A unified description of these interface surfaces is given based on the lattice gas model that enables an equally accurate calculation of molecular distributions in heterogeneous distributed models of transition regions of interfaces. Undeformable pore walls generate an external field affecting the molecular distribution and forming adsorption films due to the adsorbate–adsorbent interaction potential. Surface tensions (STs) are calculated from the excess of the free energy of the interface (according to Gibbs) for each three types of two-phase interfaces. The ST for the solid–liquid interface corresponds to the surface passing through the contacting phases, i.e., via bonds between the adsorbate and the adsorbent. The state of coexisting “vapor in a pore” and “liquid in a pore” phases must satisfy the equality of chemical potentials, excluding the appearance of metastable states. Distinctions introduced by the wall roughness are mainly observed for narrow pores and they decrease as the pore width increases. The wall roughness changes the critical parameters of fluid stratification into liquid and vapor phases. The calculated ST values are compared with similar values for smooth walls of a slitlike pore. It is found that solid–liquid and solid–vapor STs are close to each other (their difference is smaller on a rough surface than on the smooth one) and are larger (in their absolute value) than the liquid–vapor ST in the center of the pore by approximately an order of magnitude. Local vapor–liquid ST values nonmonotonically change when removed from the wall.

中文翻译：

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粗糙壁缝状孔内分层蒸气和流体的三种类型的两相表面张力

摘要

在“蒸汽和液体弯液面”系统中，在具有粗糙壁的狭缝状孔隙内考虑了三种类型的两相界面（气-液，固-气和固-液）。这些界面的统一描述是基于晶格气体模型给出的，该模型能够同样精确地计算界面过渡区域的异质分布模型中的分子分布。由于被吸附物与吸附剂的相互作用，不可变形的孔壁会产生影响分子分布并形成吸附膜的外部场。表面张力（STs）是根据每三种类型的两相界面的界面自由能（根据Gibbs）计算得出的。固液界面的ST对应于通过接触相的表面，即 通过被吸附物和吸附剂之间的键。“孔隙中的蒸气”和“孔隙中的液体”相共存的状态必须满足化学势的相等性，但不包括亚稳态。由壁粗糙度引起的区别主要在狭窄的孔隙中观察到，并且随着孔隙宽度的增加而减小。壁面粗糙度将流体分层的关键参数更改为液相和气相。对于狭缝状孔的光滑壁，将计算出的ST值与相似值进行比较。发现固液ST和固汽ST彼此靠近（在粗糙表面上的差小于在光滑表面上的差），并且在中心处（在绝对值上）大于液汽ST。孔隙的大约一个数量级。