A microfluidic method to systematically study droplet stability in highly concentrated emulsions

Preparation of high internal phase emulsions comes with many challenges. Droplet stability is hardly explored in these systems because they are not transparent, and highly dynamic. There is a clear need for advanced methods that allow elucidation of the mechanism of droplet coalescence in high internal phase emulsions. For this reason, we developed microfluidic chip that allow ultimate control over droplet size and high volume fraction. The chip concentrates emulsions in a concentration section, and subsequently allows coalescence investigation at volume fractions larger than 0.74. To illustrate the effect of surface active components, a systematic study was successfully carried out with & beta;-lactoglobulin and sodium dodecyl sulfate, thus highlighting the versatility of the approach.

Automated summary

Preparation of high internal phase emulsions presents challenges in studying droplet stability and coalescence mechanisms. A microfluidic chip was developed to precisely control droplet size and high volume fraction, allowing investigation of droplet coalescence at volume fractions larger than 0.74. The versatility of the approach was demonstrated through a systematic study using β-lactoglobulin and sodium dodecyl sulfate as surface active components.