Wettability-tuned silica particles for emulsion-templated microcapsules.

Area of Science:

• Materials Science
• Colloid and Surface Chemistry

Background:

• Pickering emulsions are crucial for advanced materials and have broad applications.
• Stabilizing diverse fluid-fluid interfaces (oil/water, ionic liquid/oil, oil/oil) is key for material fabrication.
• Silica nanoparticles are effective Pickering emulsifiers, but controlling their wettability is essential.

Purpose of the Study:

• To develop tunable, silica-based Pickering emulsifiers with controlled wettability.
• To demonstrate the stabilization of various fluid-fluid interfaces using these engineered particles.
• To utilize these emulsions as templates for creating microcapsules via interfacial polymerization.

Main Methods:

• Silanization of 22 nm SiO2 particles with reagents of varying hydrophilicity/hydrophobicity to tune wettability.
• Formation of Pickering emulsions by dispersing modified silica particles in the continuous phase.
• Coupling of particle-stabilized emulsions with interfacial polymerization to synthesize microcapsules.

Main Results:

• Successfully created wettability-tuned silica-based Pickering emulsifiers.
• Demonstrated stabilization of oil/water, ionic liquid/oil, and oil/oil interfaces.
• Fabricated polyurea/silica hybrid microcapsules using the emulsions as templates.

Conclusions:

• A single silica particle feedstock, modified for tunable wettability, can stabilize diverse fluid interfaces.
• This approach offers a versatile toolkit for creating advanced hybrid materials and microcapsules.
• The method provides a robust templating strategy for composite material fabrication.