Wetting Properties of Molecularly Rough Surfaces

0448504 - ÚCHP 2016 RIV US eng J - Journal Article
Svoboda, Martin - Malijevský, Alexandr - Lísal, Martin
Wetting Properties of Molecularly Rough Surfaces.
Journal of Chemical Physics. Roč. 143, č. 10 (2015), s. 104701. ISSN 0021-9606. E-ISSN 1089-7690
R&D Projects: GA ČR GA13-09914S; GA MŠMT LH12020
Institutional support: RVO:67985858
Keywords : contant-angle * solid-surface * dynamics
Subject RIV: BJ - Thermodynamics
Impact factor: 2.894, year: 2015

We employ molecular dynamics simulations to study the wettability of nanoscale rough surfaces in systems governed by Lennard-Jones (LJ) interactions. We consider both smooth and molecularly rough planar surfaces. Solid substrates are modeled as a static collection of LJ particles arranged in a face-centered cubic lattice with the (100) surface exposed to the LJ fluid. Molecularly rough solid surfaces are prepared by removing several strips of LJ atoms from the external layers of the substrate, i.e., forming parallel nanogrooves on the surface. We vary the solid-fluid interactions to investigate strongly and weakly wettable surfaces. We determine the wetting properties by measuring the equilibrium droplet profiles that are in turn used to evaluate the contact angles. Macroscopic arguments, such as those leading to Wenzel's law, suggest that surface roughness always amplifies the wetting properties of a lyophilic surface. However, our results indicate the opposite effect from roughness for microscopically corrugated surfaces, i.e., surface roughness deteriorates the substrate wettability.
Permanent Link: http://hdl.handle.net/11104/0250734