We report the experimental work of microparticle self-assembly in ionic liquid-based Pickering emulsions, with emphasis on bridged morphologies, stability, and particle transport. Both the morphology and stability of these emulsions differ greatly from previous work on conventional oil/water Pickering emulsions. The morphology of the previous work showed single, partially or fully covered droplets, while the water/ionic liquid, oil/ionic liquid, and ionic liquid/ionic liquid systems show a high degree bridging of the droplet phase, with the particles avoiding the droplet-continuous phase boundary. The existence of this morphology depends directly on the surface chemistry of the particles. Due to the high free energy of desorption of a particle from a Pickering emulsion interface, conventional oil/water emulsions can experience overall emulsion stability on the order of days or months. However, the emulsions containing bridged structures experience stability on the order of hours due to the large, buoyant bridged structures formed, promoting phase separation.

Understanding droplet bridging in ionic liquid-based Pickering emulsions

245th National Meeting (2013)

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