Nanosheet-Stabilized Emulsions: Near-Minimum Loading and Surface Energy Design of Conductive Networks

Area of Science:

• Materials Science and Engineering
• Colloid and Surface Chemistry
• Nanotechnology

Background:

• Functional emulsions are crucial for various applications but often require high stabilizer concentrations.
• Two-dimensional (2D) materials offer unique properties for stabilizing interfaces.
• Controlling droplet deposition and film formation is challenging due to phenomena like the coffee ring effect.

Purpose of the Study:

• To develop a versatile framework for creating and understanding functional emulsions stabilized by few-layer 2D nanosheets.
• To achieve ultralow stabilizer loading in emulsions for efficient material utilization.
• To enable controlled assembly of materials from emulsions for devices and films.

Main Methods:

• Utilized liquid-exfoliated graphene and molybdenum disulfide (MoS2) nanosheets as stabilizers.
• Investigated emulsion stability and droplet orientation based on interfacial surface energies.
• Developed a model to determine nanosheet surface energies and guide emulsion design via surface tension and pH.

Main Results:

• Demonstrated stabilization of emulsions at ultralow 2D nanosheet volume fractions.
• Achieved controlled droplet deposition, eliminating the coffee ring effect for single-droplet devices and large-area films.
• Prepared conductive silicone emulsion composites with record-low loading and enhanced electromechanical sensitivity.

Conclusions:

• The developed framework provides a robust method for designing and applying 2D nanosheet-stabilized emulsions.
• This approach facilitates the determination of nanosheet surface energies and enables tailored emulsion structures.
• Nanosheet-stabilized emulsions show significant potential for low-loading functional composites and advanced material assembly.