Mechano-responsive microcapsules with uniform thin shells

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Capsules extend shelf-life by preventing oxidation and reactions.
• Controlled release of active ingredients requires well-defined capsule shells.
• Fabricating mechanically stable microcapsules with sub-micrometer shells is challenging.

Purpose of the Study:

• To develop a method for fabricating capsules with uniform, ultra-thin shells.
• To improve control over the release kinetics of encapsulated substances.
• To create mechanically robust capsules with minimal shell volume.

Main Methods:

• Utilized water-oil-water double emulsions as templates for shell formation.
• Fabricated capsules with uniform semi-permeable shells as thin as 400 nm.
• Investigated mechanical stability and retention properties of the thin-shelled capsules.

Main Results:

• Achieved uniform capsule shells with a thickness of 400 nm, occupying <2% of capsule volume.
• Demonstrated mechanical robustness, withstanding pressures up to 1.3 MPa without deformation and up to 2.75 MPa without rupture.
• Confirmed retention of low molecular weight encapsulants after drying and re-dispersion, despite water permeability.

Conclusions:

• The novel method enables the controlled fabrication of ultra-thin, mechanically stable microcapsules.
• These capsules offer enhanced control over release kinetics and minimize shell-related defects.
• The thin-shelled capsules present new opportunities for functionalizing materials and creating advanced building blocks.