Long term water trapping in Pickering emulsions undergoing compositional ripening

Area of Science:

• Food science
• Colloid and interface science
• Materials science

Background:

• Low-calorie food development often uses water-in-oil emulsions.
• Compositional ripening, driven by solubility differences, can destabilize these emulsions.
• Water-in-oil Pickering emulsions stabilized by particles are a key area of study.

Purpose of the Study:

• To investigate compositional ripening in water-in-oil Pickering emulsions.
• To understand the role of particle stabilization in preventing mass transfer between droplets.
• To compare ripening behavior in different oil phases (dodecane and tributyrin).

Main Methods:

• Preparation of water-in-dodecane and water-in-tributyrin emulsions stabilized by PMMA particles.
• Combination of emulsions with and without sugar in the water phase.
• Confocal microscopy and particle tracking to monitor droplet evolution over time.

Main Results:

• In dodecane, pure water droplets lost water, crumpled, and sometimes exploded; sugar droplets expanded and coalesced.
• In tributyrin, pure water droplets formed stable crumpled structures, retaining water.
• Decreasing sugar concentration reduced the rate of water droplet size change in both oils.

Conclusions:

• Interfacial particle coatings were insufficient to suppress compositional ripening in these systems.
• Droplet 'explosions' demonstrate the driving force can overcome particle stabilization.
• Crumpled states in tributyrin suggest potential for mitigating ripening effects.