Three types of condensation in open wedges

TL;DR

This paper explores how finite-length open wedges exhibit three distinct condensation types and complex phase behaviors, including reentrant phenomena and higher-order transitions, differing from the well-known continuous condensation in infinite wedges.

Contribution

It introduces a detailed analysis of condensation in finite open wedges, revealing three types of condensation and complex phase transitions not present in infinite geometries.

Findings

Identification of three distinct condensation types

Reentrant phenomena observed in phase behavior

Asymptotic analysis confirmed by numerical solutions

Abstract

Condensation in linear wedges formed by semi-infinite walls is a well-established critical phenomenon characterized by the continuous growth of an adsorbed liquid layer as bulk two-phase coexistence is approached. In this study, we investigate condensation in finite-length wedges open at both ends, demonstrating that the process becomes first-order. The open boundaries and finite geometry induce a remarkably rich phase behavior of the confined fluid, exhibiting three distinct types of condensation, reentrant phenomena, and continuous higher-order transitions between condensation states. Through a detailed macroscopic analysis, we derive the conditions for each type of condensation, classify the global phase diagrams, and explore asymptotic behavior in specific limiting cases. The asymptotic predictions are confirmed by a detailed comparison with the numerical solutions of the governing equations.