(71s) Microfluidic Modules for Optimized Mixing and Heat Transfer

Since more than 10 years micromixers, micro heatexchangers and microreactors have been developed and tested for different applications. Several principles for mixers (e.g. interdigital mixers, split-and-recombine, chaotic mixers, cyclone mixers, falling films, etc.) and for heat exchangers (cross flow, counter current flow, pre-heating, electrical heating, etc.) have been realized and can be purchased as standard modules. The structurization technology for different materials like stainless steel, ceramics or glass is available. Even though all this is commercially available worldwide from different companies and research institutes, there are still special chemical issues which need optimized reaction modules. This paper will show new results about reactions in two-phase systems. Micromixers have been developed, which limit the size of plugs in a two-phase system to accelerate reactions by shortening diffusion times. This is supported by geometric channel structures which induce a chaotic behaviour of the flow. A variable dwell time module allows the adjustment of residence time according to the used chemical reaction. The system ends with a separation module which allows to stop the reaction at a certain point and to seperate the products from remaining educts and by-products. It will be shown that with such a system critical reactions, e.g. in highly viscous fluids or polymerizations, can be handled and controlled.