A continuum model for the flow of thin liquid films over intermittently chemically patterned surfaces

TL;DR

This paper develops a continuum model to describe how chemically patterned surfaces influence the flow of thin liquid films, highlighting the significant effects of wettability variations on flow behavior.

Contribution

It extends interface formation theory to intermittent chemical patterning, providing a new continuum framework for understanding flow over complex surfaces.

Findings

Wettability variations significantly affect thin film flow.

The model captures flow changes due to chemical patterning.

Potential applications in microfluidic device design.

Abstract

It is known from both experiments and molecular dynamics simulations that chemically patterning a solid surface has an effect on the flow of an adjacent liquid. This fact is in stark contrast with predictions of classical fluid mechanics where the no-slip boundary condition is insensitive to the chemistry of the solid substrate. It has been shown that the influence on the flow caused by a steep change in the wettability of the solid substrate can be described in the framework of continuum mechanics using the interface formation theory. The present work extends this study to the case of intermittent patterning. Results show that variations in wettability of the substrate can significantly affect the flow, especially of thin films, which may have applications to the design of microfluidic devices.