Nanofilms of total wetting liquids and the wetting-dewetting transition of liquid nanoplugs in graphene nanoslits
Journal
Surfaces and Interfaces
Journal Volume
70
Start Page
106853
ISSN
2468-0230
Date Issued
2025-08-01
Author(s)
Abstract
Dimethylformamide (DMF) liquid on a graphene surface exhibits total wetting behavior, with its nanofilm remaining stable at any thickness. The characteristics of the DMF nanofilm are investigated across three types of interfaces: solid/liquid/vapor, solid/liquid/solid, and vapor/liquid/vapor, where graphene surface represents the solid. This study focuses on two key objectives: (1) characterizing the stability and structural features of DMF nanofilms, and (2) investigating the wetting–dewetting transitions of DMF liquid plugs confined within graphene nanoslits. NAMD simulations reveal that as the thickness of nanofilms on graphene decreases, internal energy decreases while negative disjoining pressure increases. Additionally, the density peaks near the graphene surface but is depleted near the vapor phase. Consequently, the presence of graphene surfaces enhances the stability of the film. Furthermore, the wetting behavior of liquid nanoplugs in nanoslits, known to be stable for partial wetting but unstable for total wetting, is examined. Unexpectedly, as the channel width decreases below a critical threshold, the DMF liquid plug transitions from total wetting to partial wetting behavior, with a finite precursor film forming during the transition. Analyses of internal and free energy reveal that this wetting-dewetting transition occurs spontaneously and is thermodynamically reversible.
Subjects
Graphene
Liquid plug
Molecular dynamics
Nanofilm
Total wetting liquid
Wetting-dewetting transition
Publisher
Elsevier BV
Type
journal article