Segmented Microflows as a Tool for Optimization of Mass Transfer in Liquid−Liquid Extraction: Application at the Extraction of Europium(III) by a Malonamide

Segmented flows in T-junction glass microchannels are investigated as a tool for the study of liquid–liquid extraction kinetics of europium­(III) by a malonamide. They allow to reach higher extraction yields compared with laminar flows, for a same extraction system. After the range of volume ratio reached in microsystems and the thickness of the organic film between the aqueous plugs and the microchannel walls are determined, the extraction yields in microsystems and at equilibrium are compared. A definition of a pseudokinetic coefficient, K, is proposed, as a lower bound limit for the chemical forward coefficient kf. The evolution of this pseudokinetic coefficient is investigated as a function of the droplet velocity, and the diffusion-limited regime is identified. A model for the evolution of K is then proposed and the maximum value for K, reached for a velocity of the droplets over 20 cm s–1, is compared with literature values