Multiscale perspective on wetting on switchable substrates: mapping between microscopic and mesoscopic models

TL;DR

This paper develops a method to connect microscopic molecular dynamics data with mesoscopic thin film models to analyze non-equilibrium wetting dynamics on switchable substrates, enabling multi-scale understanding.

Contribution

It introduces a novel mapping procedure from microscopic to mesoscopic models for non-equilibrium wetting, extending previous equilibrium approaches.

Findings

Successful mapping of microscopic MD data to mesoscopic models

Analysis of droplet relaxation after substrate wettability switch

Application of the method to coalescing droplets

Abstract

To understand the non-equilibrium relaxation dynamics of a liquid droplet on a switchable substrate the interplay of different length- and time-scales needs to be understood. We present a method to map the microscopic information, resulting from a molecular dynamics simulation, to a mesoscopic scale, reflected by a thin film model. After a discussion of the mapping procedure we first analyze the relaxation of a liquid droplet upon switching the wettability of the substrate. Further, we show that a nearly identical mapping procedure can be used for the description of two coalescing droplets. With our procedure we take a first step to extend the mapping from the equilibrium case to non-equilibrium wetting dynamics, thus allowing for a quantitative multi-scale analysis.