Microfluidic Dynamic Interfacial Tensiometry (mu DIT)

Quentin Brosseau (1) , Jérémy Vrignon (2) , Jean-Christophe Baret (2)

1 MPIDS - Max Planck Institute for Dynamics and Self-Organization
2 CRPP - Centre de recherches Paul Pascal

We designed, developed and characterized a microfluidic method for the measurement of surfactant adsorption kinetics via interfacial tensiometry on a microfluidic chip. The principle of the measurement is based on the deformability of droplets as a response to hydrodynamic forcing through a series of microfluidic expansions. We focus our analysis on one perfluoro surfactant molecule of practical interest for droplet-based microfluidic applications. We show that although the adsorption kinetics is much faster than the kinetics of the corresponding pendant drop experiment, our droplet-based microfluidic system has a sufficient time resolution to obtain quantitative measurement at the sub-second time-scale on nanoliter droplet volumes, leading to both a gain by a factor of environ10 in time resolution and a downscaling of the measurement volumes by a factor of environ1000 compared to standard techniques. Our approach provides new insight into the adsorption of surfactant molecules at liquid–liquid interfaces in a confined environment, relevant to emulsification, encapsulation and foaming, and the ability to measure adsorption and desorption rate constants.

Mots clés: Microfluidic microsystem

Domaines: Dynamique des Fluides [physics.flu-dyn]; Matière Condensée [cond-mat]

Quentin Brosseau, Jérémy Vrignon, Jean-Christophe Baret. Microfluidic Dynamic Interfacial Tensiometry (mu DIT). Soft Matter, 2014, 10 (17), pp. 3066-3076. ⟨10.1039/c3sm52543k⟩. ⟨hal-01122752⟩