(179k) Engineering of Pickering Emulsion Templated Colloidosomes and Fundamentals of Emulsification with Nano-Particles

Colloidosomes are semipermeable microcapsules with external shell formed by colloidal particles, providing promising technique for encapsulations with controllable permeability, mechanical properties and bio-compatibility. Our work explores double Pickering emulsion, also known as particle stabilized emulsions, as precursors to synthesize composite colloidosomes for triggered and sustainable release control with envisioned applications in flexographic printing and biomedical aspects. To generate such colloidosomes, a prerequisite is the controlled formation and stabilization of Pickering emulsions. Unfortunately, our current fundamental understanding of Pickering emulsions is still far from satisfactory and often fails to predict reliably the stability and the type of Pickering emulsions. We therefore focus on understanding the fundamentals of Pickering emulsions by researching emulsifications with polymeric nano-particles. Our study suggests two widely neglected electrostatic effects in Pickering emulsions, one is the effect of image charge repulsion on the emulsion formation, and the second is the effect of dipole-interaction on the preferred emulsion type. The obtained new insights will benefit not only our design of colloidosomes but realms relevant to Pickering emulsions