Vacancy-induced modulation of interfacial properties and flow dynamics of water in two-dimensional hexagonal boron nitride confinement
Journal
Journal of the Taiwan Institute of Chemical Engineers
Journal Volume
188
Start Page
106914
ISSN
1876-1070
Date Issued
2026-11
Author(s)
Abstract
Background Atomic-scale defects in two-dimensional materials can substantially affect fluid behavior at the nanoscale. Methods In this study, molecular dynamics simulations are employed to investigate the effects of monovacancy defects on the surface wettability and flow dynamics of water in hexagonal boron nitride nanoconfinements. Wettability is characterized using sessile nanodroplet and liquid plug configurations, while non-equilibrium simulations are used to extract velocity profiles, local viscosity, and slip length under steady-state flow conditions. Significant findings Hydrophilicity is enhanced by monovacancy defects via reduced internal energy. For flow in nanoscale slits, the presence of vacancy defects induces a transition from uniform to laminar flow velocity profiles, accompanied by a pronounced reduction in slip velocity. The local viscosity distribution exhibits layering consistent with density oscillations. Both the effective viscosity and slip length—extracted via Hagen-Poiseuille fitting—increase rapidly as the defect concentration approaches zero. The introduction of vacancy defects produces shoulder-like features in the density profile near the walls, disrupting the spatial ordering of confined water. This effect leads to a decrease in viscosity, which eventually plateaus at sufficiently high defect concentrations.
Subjects
Hexagonal boron nitride
Local viscosity
Monovacancy defect
Slip length
Surface wettability
Publisher
Elsevier BV
Type
journal article