In a recent study published in Physical Review E, Dr. Jiří Janek and Prof. Alexandr Malijevský from the Research Group of Molecular and Mesoscopic Modelling, have unveiled remarkably rich condensation phenomena in confined geometries. The study, titled Three Types of Condensation in Open Wedges, explores how fluids behave in open wedge-shaped geometries — confinements that differ significantly from the simple classical models of planar or cylindrical capillary systems.
This theoretical research demonstrates that condensation in such open systems is of first-order and the authors identify three distinct condensation regimes: Single-Pinning (SP), Semi-Double-Pinning (SDP), and Double-Pinning (DP) – each characterized by unique meniscus configurations and governed by a delicate interplay between the system geometry and the wall wetting properties. Using the analytical calculations, complemented by numerical verifications, the team constructed a set of global phase diagrams and provided asymptotic analyses that capture the system phase behavior under various limiting conditions. Additionally, the study reveals reentrant phenomena and higher-order transitions, showing an unusually complex phase behavior of this system.
This work represents a significant advance in the theory of phase transitions with promising implications across fields such as porous materials, nanofluidics, and surface engineering, bridging the fundamental insights with potential technological applications. By uncovering the mechanisms controlling various types of system condensation leading to different liquid morphologies, the work provides a foundation for predicting and controlling phase behavior in complex inhomogeneous systems.
A sequence of equilibrium condensed states in an open wedge illustrating how the type of condensation varies with α. Yellow – DP, Green – SDP, Blue – SP. Note the SDP reentrance
- Janek J., Malijevský A.*: Three types of condensation in open wedges. Rev. E. 2025, 111, 045507. doi.org/10.1103/PhysRevE.111.045507