8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P6.40Fri 911:10-14:00Microfluidic flow-chemistry for the generation of highlystructured liquid and solid polymer foamsAouatef Testouri, 1 Meik Ranft, 2 Antje Van der Net, 2 Dominiqe Langevin, 1 WiebkeDrenckhan, 1 and Clement Honorez 11 Laboratoire de physique des solides, université paris sud batiment 510, 91405, Orsay,France2 BASF, Ludwigshafen, GermanyThe well-controlled flow-conditions present in microfluidic devices provide excellent means ofperforming in-line chemical reactions, in which concentrations, mixing, and reaction time-scalescan be easily adjusted by appropriately tuning channel geometries and flow rates. The samekind of devices can be used to generate and manipulate multi-phase systems, such as foams oremulsions, with extremely well-controlled structural properties. We show here how both, flowchemistry and multiphase flow, can be combined to generate highly structured “porous liquids”(foams [1]) from a range of aqueous or non-aqueous solutions, which solidify in-situ to turn intoporous solids with well-defined porosity and density. For this purpose, we use micro/millifluidicflow techniques to generate extremely monodisperse bubbles in a fluid which may containmonomers, polymers, or their mixtures, and appropriately chosen surface active agents to stabilizethe bubbles. The on-chip addition of reticulating agents leads to the formation of physically orchemically cross-linked polymer networks in the generated foam and hence to its solidification.Within this research we touch upon a large number of fundamental scientific questions: How tochoose appropriate surface active agents? How to reliably manipulate and generate bubbles incomplex fluids in microfluidic devices? How to mix reactive agents in microfluidic conditions?How to match the various time-scales related to the flow patterns, the chemical reactions andthe foam stability? We will discuss and answer some of these questions, using in particular theexample of biopolymer [2] and superabsorbing hydrogel foams [3].[1]. Drenckhan, W. and D. Langevin, COCIS, 2010. 15(5): p. 341-358.[2]. A. Testouri, C. Honorez, A. Barillee, D. Langevin, W. Drenckhan, Macromolecules, 2010.43(14): p. 6166-6173.[3] A. van der Net, A. Gryson, M. Ranft, F. Elias, C. Stubenrauch, W. Drenckhan, Coll. Surf. A,2009. 346(1-3): p. 5-1040