Transient structures in rupturing thin films: Marangoni-induced symmetry-breaking pattern formation in viscous...

Area of Science:

• Fluid dynamics
• Materials science
• Soft matter physics

Background:

• Soap bubbles exhibit complex transient patterns before rupture, linked to Marangoni flow instabilities.
• Surfactant solutions create curved, thin films with dynamic behaviors.
• Understanding these patterns is crucial for controlling thin film stability.

Purpose of the Study:

• To develop a theoretical model for pattern formation in curved, surfactant-laden thin films.
• To describe the dynamics of quasielastic wrinkling and coarsening.
• To validate the model against experimental observations of soap bubbles.

Main Methods:

• Derivation of a generalized Cahn-Hilliard-Swift-Hohenberg model using asymptotic theory.
• Quantitative comparison of theoretical predictions with experimental data from soap bubbles.
• Analysis of nucleation and early coarsening phases of pattern development.

Main Results:

• The model accurately describes quasielastic wrinkling pattern formation in curved thin films.
• Quantitative agreement was found between theoretical predictions and experimental results for nucleation and early coarsening.
• The study elucidates the physical mechanisms behind pattern dynamics.

Conclusions:

• The developed model provides fundamental physical insights into thin film behavior with surfactants.
• Findings can inform strategies for stabilizing or destabilizing thin films.
• Implications extend to industrial processes involving foams, emulsions, sprays, and coatings.