Tuning Interactions between Charged Structured Colloids and Hydrophobic Salts for the Production of Pickering Emulsifiers

Pickering emulsifiers have been demonstrated as advantageous alternatives to traditional small molecule surfactants, owing to their high interfacial adsorption energy and mechanical functionality. However, translating these advantages on an industrial scale requires continuous fabrication processes. Flash nanoprecipitation (FNP) has been demonstrated as a scalable process for the production of nanocolloids with a rich library of morphologies including homogeneous, core-shell, and Janus structures, the last of which presents an opportunity for generating amphiphilic Pickering emulsifiers. In this work, the FNP of homopolymers with ionomer analogs is presented as a route for the tunable expression of charge groups on distinct hemispheres of Janus particles. Utilizing this enhanced surface charge, the interaction between colloids and hydrophobic salts is studied, showing non-monotonic trends in size stability. Lastly, the surface activity of various colloid-salt combinations is demonstrated via the formation of highly stable Pickering emulsions.