Microfluidic interfacial rheology of capsules

Started: 2013

Co-authors: Nadège Pantoustier, Patrick Perrin, Thomas Salez, Mathilde Reyssat, Cécile Monteux.

Location: SIMM, ESPCI-Paris, France – Gulliver,  ESPCI-Paris, France.

Using PDMS-based microfluidics, multilayers of polymers were assembled on oil droplets to make capsules. These capsules were injected in a glass microfluidic chip in which they crossed a large chamber. The extensional shear stress at the entrance of the chamber deforms the capsules which then relax due to interfacial tension. The analysis of the deformation and relaxation of the capsules, compared to a semi-analytical prediction coupling a visco-elastic model and finite element simulations to know the viscous stress enables the extraction of capillary, elastic and viscous relaxation times for various compositions of the interface.