Non-covalent reconfigurable microgel colloidosomes with a well-defined bilayer shell.

Area of Science:

• Materials Science
• Colloid and Surface Chemistry
• Polymer Science

Background:

• Microgels are effective Pickering emulsion stabilizers, typically forming oil-in-water emulsions due to their hydrophilicity.
• Existing methods lack control over microgel interfacial layer structure, limiting advanced material applications.
• Stabilization of inverse water-in-oil emulsions using microgels is challenging.

Purpose of the Study:

• To develop a method for creating stable inverse water-in-oil Pickering emulsions using microgels.
• To control the structural layers of microgels at interfaces for advanced applications.
• To engineer microgel-based colloidosomes with tunable shells for encapsulation and controlled release.

Main Methods:

• Introducing octanol into poly(N-isopropylacrylamide-co-methacrylic acid) (PNIPAM-co-MAA) microgels to create octanol-swollen microgels.
• Utilizing octanol-swollen microgels to stabilize inverse water-in-oil Pickering emulsions.
• Employing these emulsions as templates to form microgel colloidosomes ('microgelsomes') with tunable shell structures (monolayer to bilayer).

Main Results:

• Octanol-swollen microgels rapidly diffuse to the oil-water interface, forming elastic interfacial layers.
• Stable inverse water-in-oil Pickering emulsions were successfully generated.
• Tunable microgel-bilayer shells were formed on microgelsomes, enabling encapsulation and anchoring of various substances (nanoparticles, proteins, enzymes).
• Programmed release of encapsulated substances was achieved using ethanol as a trigger.

Conclusions:

• Octanol-swollen microgels enable the formation of stable inverse Pickering emulsions and tunable microgelsomes.
• The reconfigurable microgelsomes with bilayer shells respond to stimuli, offering tailored properties.
• This approach expands the application scope of microgels and Pickering emulsions in advanced materials and delivery systems.