Polymer microcapsules with "foamed" membranes.

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Poly(methylmethacrylate) (PMMA) capsules are versatile for various applications.
• Controlling capsule morphology and internal structure is crucial for tailored functionality.
• Solvent evaporation is a common technique for microcapsule fabrication.

Purpose of the Study:

• To describe the preparation of PMMA capsules with surface craters and internal holes.
• To investigate the influence of a fatty acid triglyceride (miglyol 812) excipient on capsule morphology.
• To analyze the distribution of components within the prepared capsules.

Main Methods:

• Solvent evaporation process for PMMA capsule preparation.
• Use of polyvinyl alcohol as a dispersant.
• Spectroscopic methods, including confocal fluorescence microscopy, for structural analysis.
• Analysis of surface tension and hydrophile-lipophile balance (HLB) for phenomenon generalization.

Main Results:

• Capsules ranged from 20 to 200 microm in diameter, exhibiting surface craters (1-2 microm) and internal holes.
• Miglyol content significantly altered the membrane structure, from 'soft-part-of-bread' to 'foamed' aspects.
• Confocal fluorescence microscopy confirmed miglyol localization in the core, not craters or holes, and water filling the holes.
• A phenomenon analysis based on oil surface tensions and HLB was proposed.

Conclusions:

• The solvent evaporation method allows for the creation of PMMA capsules with tunable surface and internal structures.
• The fatty acid triglyceride excipient plays a key role in dictating capsule morphology and internal organization.
• Confocal fluorescence microscopy is effective in characterizing component distribution within complex capsule architectures.
• The study provides insights into controlling microcapsule properties for potential applications.