Molecular mechanism of electrostatic field-enhanced water vapour absorption at the gas-solution Interface
File(s)
Accepted version
Author(s)
Fan, Fangsu
Yin, Yonggao
Xu, Guoying
Chen, Wanhe
Markides, Christos N
Type
Journal Article
Abstract
Gas-solution mass transfer is critical in industrial manufacturing, chemical processing, and indoor humidity control. Liquid desiccant dehumidification (LDD) systems offer energy-efficient, environmentally friendly humidity control by utilising low-grade heat and avoiding conventional refrigerants, but their performance is limited by low interfacial vapour absorption. Interfacial transport—absorption, reflection, and release—is governed by structural properties, providing a molecular-level perspective for performance enhancement. This study proposes active control of water vapour transport at the LiBr solution vapour-liquid interface using an external electrostatic field (E-field) applied along the mass transfer direction to induce interfacial polarisation. Molecular dynamics (MD) simulations show that the E-field increases net absorption, with positive fields more effective than negative ones. Both polarities enhance absorption by reorienting water dipoles, disrupting hydrogen-bond (H-bond) networks, and promoting diffusion. Reflection and release are highly polarity-dependent: positive fields enrich Li+ at the interface, strengthening hydration, trapping water, and suppressing release; negative fields deplete Li+ and accumulate Br−, weakening hydration, and facilitating release. These findings provide a molecular framework for enhancing interfacial mass transfer through external field modification to improve dehumidification and may also guide optimisation of other gas-liquid processes involving polar molecules.
Date Issued
2025-12-01
Date Acceptance
2025-09-01
Citation
International Communications in Heat and Mass Transfer, 2025, 169 (Part B)
ISSN
0735-1933
Publisher
Elsevier
Journal / Book Title
International Communications in Heat and Mass Transfer
Volume
169
Issue
Part B
Copyright Statement
Copyright © 2025 Elsevier Ltd. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Subjects
ALGORITHM
Diffusion coefficient
DYNAMICS
EVAPORATION
LENNARD-JONES
LIQUID DESICCANT
LITHIUM BROMIDE
Mechanics
Molecular dynamics simulation
Physical Sciences
Polarisation effect
Science & Technology
Technology
Thermodynamics
Vapour-liquid interface
Water absorption
Publication Status
Published
Article Number
109610
Date Publish Online
2025-09-02