Stabilization of water-in-water emulsions by bis-hydrophilic copolymers for the fabrication of all aqueous capsules – WATCAPS

Water-in-water (W/W) emulsions are obtained by mixing in water two hydrophilic incompatible polymers. Stable W/W emulsions have a rich potential for applications such as encapsulation of hydrophilic molecules. So far, stabilization of W/W emulsions against coalescence has been tried by adding particles. This process is effective for oil/water emulsions, but often doesn't work for W/W emulsions and the conditions leading to stable W/W emulsions remain unclear. Moreover, adding particles doesn’t allow easy control of the droplet size and the interface permeability. Importantly, W/W emulsions stabilized by particles are not resistant to dilution, which is detrimental for many applications. To address these issues, we propose to use bis-hydrophilic copolymers that stabilize W/W emulsions by spontaneously forming a protective layer at the droplet interface. The aim of the project WATCAPS is to produce well-defined aqueous capsules by crosslinking the bis-hydrophilic copolymers in the layer.