• Benzi, Roberto
• Toschi, Federico
• Staso, Gianluca Di
• Girotto, Ivan
• Schifano, Sebastiano F.
• Scagliarini, A.

Abstract

Stabilised dense emulsions display a rich phenomenology connecting microstructure and rheology. In this work, we study how an emulsion with a finite yield stress can be built via large-scale stirring. By gradually increasing the volume fraction of the dispersed minority phase, under the constant action of a stirring force, we are able to achieve a volume fraction close to 80%<br/>. Despite the fact that our system is highly concentrated and not yet turbulent we observe a droplet size distribution consistent with the −10/3<br/> scaling, often associated with inertial range droplets breakup. We report that the polydispersity of droplet sizes correlates with the dynamics of the emulsion formation process. Additionally, we quantify the visco-elastic properties of the dense emulsion finally obtained and we demonstrate the presence of a finite yield stress. The approach reported can pave the way to a quantitative understanding of the complex interplay between the dynamics of mesoscale constituents and the large-scale flow properties of yield stress fluids.

Topics

• impedance spectroscopy
• microstructure
• phase
• polydispersity