Self-Assembly of TiO₂ Nanofiber-Based Microcapsules by Spontaneously Evolved Multiple Emulsions

Area of Science:

• Materials Science
• Nanotechnology
• Colloid Chemistry

Background:

• Colloidosomes are microcapsules formed from colloidal particles.
• Titanium dioxide (TiO2) nanomaterials offer unique properties for various applications.
• Fabricating complex TiO2 structures with controlled morphology remains a challenge.

Purpose of the Study:

• To develop a simple and versatile method for fabricating hierarchical nest/crust-like TiO2 colloidosomes.
• To investigate the mechanisms of colloidosome formation from specific emulsions.
• To explore the influence of experimental parameters on the morphology of TiO2 colloidosomes.

Main Methods:

• Utilizing spontaneously evolved n-butanol/water/n-butanol (B/W/B) emulsions.
• Employing dewetting of nanofiber-coated B/W/B droplets.
• Investigating amphiphilic polymer-stabilized B/W/B droplets.
• Analyzing the effect of droplet size, nanofiber concentration, and solvent ratios.

Main Results:

• Demonstrated two distinct mechanisms for TiO2 colloidosome formation: porous capsules and crust-like shells.
• Achieved hierarchical structures composed of interlocked TiO2 nanofibers.
• Identified key parameters influencing colloidosome morphology and formation pathways.

Conclusions:

• A facile and adaptable approach for TiO2 colloidosome fabrication was established.
• The resulting TiO2 colloidosomes exhibit potential as host systems for diverse applications.
• Potential applications include electrochemical catalysis, photothermal therapy, and advanced filtration materials.