Tunable Self-Emulsification Via Viscoelastic Control of Marangoni-Driven Interfacial Instabilities

Area of Science:

• Soft Matter Physics
• Fluid Dynamics
• Materials Science

Background:

• Interfacial instabilities in multicomponent fluids are common but difficult to control.
• Marangoni-driven self-emulsification is a key phenomenon in liquid-liquid systems.

Purpose of the Study:

• To present a novel strategy for actively tuning interfacial instabilities using fluid viscoelasticity.
• To investigate the role of polymers in controlling Marangoni-driven self-emulsification.

Main Methods:

• Utilizing high-molecular-weight polymers to introduce viscoelasticity into a water-alcohol and oil system.
• Employing high-resolution experimental visualization to observe droplet dynamics.
• Conducting theoretical analysis to quantify the relationship between viscoelasticity and instability.

Main Results:

• Increasing fluid viscoelasticity systematically suppresses interfacial instabilities.
• Delayed onset of fragmentation and longer spreading fingers were observed with higher polymer concentrations.
• A quantitative relationship between polymer concentration and finger length before breakup was established.

Conclusions:

• Viscoelasticity offers a robust method to control Marangoni-driven self-emulsification.
• The findings provide a predictive framework for designing materials with tunable interfacial dynamics.
• This research opens avenues for surface-tension-mediated patterning and fluidic control in soft materials.