Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - MicroParticleControl (Controlled synthesis of particulate matter in microfluidics)

Teaser

Despite the many advantages of microchemical systems and their successful applications in chemical engineering research, one major drawback greatly limiting their use is their susceptibility to channel clogging for flows containing particulate matter. Hence, the aim of the...

Summary

Despite the many advantages of microchemical systems and their successful applications in chemical engineering research, one major drawback greatly limiting their use is their susceptibility to channel clogging for flows containing particulate matter. Hence, the aim of the proposed research is to overcome the challenge of clogging in microfluidic devices and to design microfluidic systems that can tolerate particulate matter and synthesize solid materials according to their specifications (e.g. size, purity, morphology). To reach this goal, we apply a combined experimental and theoretical approach, in which the experimental results will lead to model development reflecting the particle formation and interaction kinetics and their coupling to the hydrodynamics. The novel concept of the proposal is to devise engineering strategies to handle the particulate matter inside the reactor and we will design different ultrasound application strategies and introduce nucleation sites to control the location of particle formation within the microchannel. This project will provide fundamental insight into the physico-chemical phenomena that result in particle formation, growth and agglomeration processes in continuous flow microdevices, and will lead to innovative microreactor designs.

Work performed

We have developed a numbered-up ‘large scale’ acoustofluidic chip for chemical synthesis, which makes use of the acoustic focusing effect, which pushes the formed particles away from the reactor walls. This focusing effect not only prevents clogging of the microchannel, but also leads to smaller particle sizes and a narrower size distribution.

We developed a two-phase system where we introduce micro-bubbles in a mirocreator and use their presence to i) achieve crystallization of an organic molecule; ii) ensure long-time operation of the device without clogging.

We have tested and implemented different numerical codes, and we systematically evaluated them in terms of their applicability to clogging prediction in microreactors.

Final results

We have designed and continue to improve novel ultrasound integrated microreactors operating at different frequency ranges depending on the intended application. These reactors have been successfully applied to various particle forming reactions, which can now be operated without the risk of clogging. Secondly, we make use of gas-liquid and liquid-liquid systems to control the particle formation process even further. Furthermore, we have developed a code that allows the prediction of clogging in microfluidics, which will improve future designs of microreactors.