Collapse of a hemicatenoid bounded by a solid wall: instability and dynamics driven by surface Plateau border friction

TL;DR

This paper investigates the collapse dynamics of hemicatenoids bounded by a solid wall, emphasizing the role of surface Plateau border friction and providing numerical and experimental insights into the process.

Contribution

It introduces a model incorporating classical friction laws for surface Plateau borders, explaining hemicatenoid collapse in confined geometries, supported by numerical and experimental results.

Findings

Collapse driven by SPB friction matches experimental observations.

Frictional forces significantly influence hemicatenoid dynamics.

Model explains bubble fragmentation in confined spaces.

Abstract

The collapse of a catenoidal soap film when the rings supporting it are moved beyond a critical separation is a classic problem in interface motion in which there is a balance between surface tension and the inertia of the surrounding air, with film viscosity playing only a minor role. Recently [Goldstein, et al., Phys. Rev. E 104, 035105 (2021)], we introduced a variant of this problem in which the catenoid is bisected by a glass plate located in a plane of symmetry perpendicular to the rings, producing two identical hemicatenoids, each with a surface Plateau border (SPB) on the glass plate. Beyond the critical ring separation, the hemicatenoids collapse in a manner qualitatively similar to the bulk problem, but their motion is governed by the frictional forces arising from viscous dissipation in the SPBs. Here we present numerical studies of a model that includes classical friction laws for SPB motion on wet surfaces and show consistency with our experimental measurements of the temporal evolution of this process. This study can help explain the fragmentation of bubbles inside very confined geometries such as porous materials or microfluidic devices.