Three Types of Two-Phase Surface Tensions of Stratified Vapor and Fluid inside a Slitlike Pore with Rough Walls

Autor: E. S. Zaitseva, Yu. K. Tovbin
Rok vydání: 2021
Předmět:
Zdroj: Protection of Metals and Physical Chemistry of Surfaces. 57:260-270
ISSN: 2070-206X
2070-2051
DOI: 10.1134/s2070205121020106
Popis: 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.
Databáze: OpenAIRE
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