One-Step Bulk Fabrication of Polymer-Based Microcapsules with Hard-Soft Bilayer Thick Shells

Area of Science:

• Materials Science
• Chemical Engineering
• Polymer Science

Background:

• Microcapsules are vital for cargo protection and delivery but often lack mechanical strength for product formulation.
• Existing methods for strong microcapsules, like microfluidics, are slow and limit production volume.

Purpose of the Study:

• To develop a high-throughput, one-step method for fabricating strong bilayer microcapsules.
• To overcome the mechanical weakness and fabrication limitations of current microencapsulation techniques.

Main Methods:

• Exploited ternary liquid mixture phase separation induced by water diffusion.
• Utilized bulk emulsification to create double emulsions, followed by UV-initiated polymerization.
• Incorporated monomers, cross-linkers, initiator, and γ-butyrolactone for shell formation.

Main Results:

• Achieved high-throughput fabrication of strong bilayer microcapsules in minutes.
• Developed microcapsules with a unique hard-soft bilayer structure.
• Demonstrated resilient, eggshell-like fracture behavior in the microcapsule shells.

Conclusions:

• The one-step bulk emulsification and phase separation method offers a scalable solution for producing mechanically robust microcapsules.
• This technique enables the rapid, large-scale production of advanced encapsulation systems with tailored mechanical properties.
• The developed strong bilayer microcapsules are suitable for applications requiring enhanced durability during processing and use.