Bicontinuous structured liquids with sub-micrometre domains using nanoparticle surfactants

Area of Science:

• Colloid and Surface Science
• Materials Science
• Soft Matter Physics

Background:

• Bicontinuous jammed emulsions (bijels) exhibit complex, interconnected structures of immiscible liquids.
• Current fabrication methods yield large domain sizes (≥5 µm), limiting practical applications in catalysis, energy storage, and encapsulation.
• Difficulty in fabrication and large domain sizes are key barriers to bijel utilization.

Purpose of the Study:

• To develop a novel method for fabricating bijels with sub-micrometre domain sizes.
• To overcome the limitations of traditional spinodal decomposition methods for bijel formation.
• To enable versatile and scalable production of bijels for diverse applications.

Main Methods:

• Utilized homogenization techniques instead of spinodal decomposition.
• Employed nanoparticle surfactants with complementary functionalities (e.g., ion-pairing) to bind at the oil-water interface.
• Stabilized bijel structures at low interfacial tensions (around 20 mN/m).

Main Results:

• Successfully formed bijels with sub-micrometre domain sizes.
• Achieved stabilization of the bijel structure away from the liquid demixing point.
• Demonstrated the versatility of the method by varying solvent, nanoparticle, and ligand components.

Conclusions:

• Homogenization with nanoparticle surfactants provides a viable route to sub-micrometre bijels.
• This approach overcomes previous fabrication barriers, expanding the potential applications of bijels.
• The developed strategy offers high versatility for tailoring bijel properties.