Surrogate models for studying the wettability of nanoscale natural rough surfaces using molecular dynamics

Lingru Zheng, Maja Rücker, Tom Bultreys, Apostolos Georgiadis, Miranda M. Mooijer-van den Heuvel, Fernando Bresme, J.P. Martin Trusler, Erich A. Müller (Corresponding author)

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

A molecular modeling methodology is presented to analyze the wetting behavior of natural surfaces exhibiting roughness at the nanoscale. Using atomic force microscopy, the surface topology of a Ketton carbonate is measured with a nanometer resolution, and a mapped model is constructed with the aid of coarse-grained beads. A surrogate model is presented in which surfaces are represented by two-dimensional sinusoidal functions defined by both an amplitude and a wavelength. The wetting of the reconstructed surface by a fluid, obtained through equilibrium molecular dynamics simulations, is compared to that observed by the different realizations of the surrogate model. A least-squares fitting method is implemented to identify the apparent static contact angle, and the droplet curvature, relative to the effective plane of the solid surface. The apparent contact angle and curvature of the droplet are then used as wetting metrics. The nanoscale contact angle is seen to vary significantly with the surface roughness. In the particular case studied, a variation of over 65° is observed between the contact angle on a flat surface and on a highly spiked (Cassie-Baxter) limit. This work proposes a strategy for systematically studying the influence of nanoscale topography and, eventually, chemical heterogeneity on the wettability of surfaces.

Original languageEnglish
Article number2770
Number of pages19
JournalEnergies
Volume13
Issue number11
DOIs
Publication statusPublished - Jun 2020
Externally publishedYes

Keywords

  • Coarse grain
  • Contact angle
  • Molecular dynamics
  • Natural roughness
  • Wettability

Fingerprint Dive into the research topics of 'Surrogate models for studying the wettability of nanoscale natural rough surfaces using molecular dynamics'. Together they form a unique fingerprint.

Cite this