Microfluidic dissolution of nanoemulsions in solvents

Area of Science:

• Colloid and Interface Science
• Fluid Dynamics
• Materials Science

Background:

• The stability of oil-in-water colloidal dispersions is crucial for various applications.
• Miscible solvents can induce complex instabilities in emulsions, affecting their behavior.
• Understanding these instabilities is key to controlling emulsion properties.

Purpose of the Study:

• To experimentally investigate the behavior of nanoemulsion and microscale emulsion jets in solvents.
• To reveal microflow patterns and understand the dynamics of emulsion threads.
• To develop methods for controlling emulsion stability and degradation using microfluidics.

Main Methods:

• Utilizing coaxial microfluidic devices for controlled jet flow experiments.
• Observing and analyzing microflow patterns, including dissolving, diffusive, gravitational, and stable thread regimes.
• Developing scaling relationships based on effective diameter, persistence, and gravitational lengths to model thread dynamics.

Main Results:

• Identified and characterized distinct flow regimes for oil-in-water emulsion threads in isopropanol.
• Developed scaling relationships to model emulsion thread dynamics.
• Established a microflow method based on dynamic similitude to estimate diffusion coefficients of emulsions in solvents.

Conclusions:

• Microfluidic techniques offer a powerful approach to process soft colloidal dispersions.
• It is possible to control the degradation mechanisms of emulsions using microfluidic devices.
• The developed methods provide insights into emulsion behavior in miscible solvents.