Role of surfactant-induced Marangoni stresses in retracting liquid sheets

TL;DR

This study investigates how insoluble surfactants influence the retraction and stability of thin water sheets, revealing that Marangoni stresses can delay breakup and significantly affect the sheet's dynamics.

Contribution

It introduces a coupled interface-tracking model to analyze surfactant effects on liquid sheet retraction, highlighting the role of Marangoni stresses at high elasticity numbers.

Findings

Surfactants can prevent or delay rim breakup.

Marangoni stresses significantly influence sheet retraction.

Elasticity number affects interface rigidification.

Abstract

In this work, we study the effect of insoluble surfactants on the three-dimensional rim-driven retraction dynamics of thin water sheets in air. We employ an interface-tracking/level-set method to ensure the full coupling between the surfactant-induced Marangoni-stresses, interfacial diffusion, and inertia. Our findings are contrasted with the (Newtonian) dynamics of a liquid sheet edge finding that the surfactant concentration can prevent, or delay, the breakup of the rim. Our simulations use the fastest growing Rayleigh-Plateau instability to drive droplet detachment from the fluid sheet (rim). The results of this work unravel the significant role of Marangoni stresses in the retracting sheet dynamics at large elasticity numbers. We study the sensitivity of the dynamics to the elasticity number and the rigidification of the interface.