Un outil microfluidique pour étudier la cinétique de nucléation de cristaux

A microfluidic tool to investigate the kinetics of crystal nucleation

LOF, unité mixte Rhodia – CNRS – Bordeaux 1, 178 avenue du Docteur Schweitzer, F–33608 Pessac Cedex - France

Auteur de correspondance : philippe.laval-exterieur@eu.rhodia.com

Abstract

We have developed an original microfluidic system to study fast kinetics of temperature-dependent processes in an emulsion. Using flow focusing geometries [Anna et al., 2003, Appl. Phys. Lett. 82 : 364], aqueous droplets are continuously formed in an oil flow. These droplets, acting as microreactors (100 nL), contain the solution to be investigated, and are formed at high temperature. They flow in a microchannel to a cooled area through a controlled temperature gradient (typically from 60 to 10°C in a few seconds). Along the microchannel, the distance being equivalent to the time thanks to the use of droplets, the kinetics of the process can be followed (from 10 to 300 s). In particular, the microdevice has been used to study the kinetics of crystal nucleation of a solute dispersed in water after a temperature quench.