A Simple Non-Embedded Single Capillary Device for On-Demand Complex Emulsion Formation

Area of Science:

• Fluid dynamics
• Materials science
• Chemical engineering

Background:

• Producing complex emulsions with multiple cores or specific structures is challenging.
• Existing methods often lack precise control over droplet formation and morphology.

Purpose of the Study:

• To design, fabricate, and test a rudimentary droplet generator for controlled emulsion production.
• To investigate the physics of double droplet formation and break-up.
• To predict droplet morphology based on interfacial tension ratios and flow parameters.

Main Methods:

• Fabrication of a capillary-based droplet generator.
• Experimental observation of pendant double droplet formation.
• Analysis of force equilibrium during droplet break-up.
• Calculation of shell thickness based on flow rates and formation time.

Main Results:

• Successfully generated double droplets through a controlled pinching-off process.
• Demonstrated the ability to tailor emulsion morphology by manipulating interfacial tension.
• Developed a method to calculate shell thickness in core-shell structures.

Conclusions:

• The developed droplet generator offers a simple and promising platform for producing double and higher-order emulsions.
• This technology enables controlled manufacturing of complex emulsions for diverse applications.
• Potential applications include microparticle fabrication and studying emulsion dynamics.