Microcapillary flow method to investigate emulsion droplet deformability

Emulsions are complex systems widely used in many relevant industrial applications, such as in the food, biomedical and petrochemical fields. They are metastable systems composed of oil, water and surfactants, and show complex structures at rest spanning different spatial scales and depending on composition and temperature. Although the phase behavior of emulsions at rest has been thoroughly investigated, the behavior of emulsions under flow still remains an open question. In particular, emulsion droplet deformation in microconfined conditions is a topic of relevant importance because of its applications in a wide range of processes, such as flow in porous media and transdermal drug delivery. In this work, a microfluidic device to investigate the effect of different oils as emulsion continuous phase on droplet deformability is presented by measuring in situ the interfacial tension of water in oil emulsions flowing in a microcapillary.