Cage-like microstructures via sequential Ugi reactions in aqueous emulsions.

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Colloid Science

Background:

• Colloidosomes are promising microcapsules with potential applications in drug delivery and encapsulation.
• Controlling the porosity and size of colloidosomes is crucial for tailoring their functionality.
• Ugi reactions offer a versatile platform for constructing complex molecular architectures.

Purpose of the Study:

• To develop a novel method for synthesizing cage-like microstructures with tunable surface porosity.
• To investigate the formation of colloidosomes using sequential Ugi reactions on Pickering emulsions.
• To control the pore size of the resulting colloidosomes by adjusting cross-linking density.

Main Methods:

• Sequential Ugi reactions were employed in a two-step process.
• Submicron colloidal particles of carboxymethylcellulose and chitosan were prepared in aqueous suspension.
• Ugi reactions were performed on the surface of toluene-based Pickering emulsions.
• Toluene removal and redissolution in water yielded the final colloidosomes.

Main Results:

• Cage-like microstructures (colloidosomes) with large surface holes were successfully synthesized.
• The pore size of the colloidosomes could be controlled by varying the cross-link density during the Ugi reaction.
• The method demonstrated the feasibility of using Ugi chemistry on emulsion interfaces for microstructure fabrication.

Conclusions:

• Sequential Ugi reactions provide an effective route to fabricate tunable colloidosomes.
• The developed method allows for precise control over the surface morphology and pore size of microstructures.
• These findings open avenues for creating advanced materials with tailored properties for various applications.