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Traditional industrial techniques to create emulsifications, like stirring, struggle to create real monodiperse emulsion and consume relatively large amount of energy. They also heat up the product in the process, possible damaging it.
In several project Researchers of the University of Wageningen have used Micronit's chips to model and demonstrate the feasibility to use microfluidic droplet generators on an industrial scale.
The monodisperse droplets generated this way can be used to improve foods, drugs, and personal care products.
More information on this research can be found on:
http://www.fpe.wur.nl/UK/Research/Membranes/large-scale+production/
Characterization of emulsification at flat microchannel Y junctions
Steegmans, M.L.J.; Schroën, C.G.P.H.; Boom, R.M.
Food and Bioprocess Engineering Group, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
Langmuir 25 (2009)6, p. 3396 - 3401, ISSN 0743-7463
Abstract
Y junctions with a large width-to-depth ratio were used for the emulsification of hexadecane in various ethanol/water mixtures with different static interfacial tension and viscosity. The resulting droplets were monodisperse. To describe droplet size a force-balance model was derived and was found to apply well. The model shows that the droplet size scales with the channel depth, and with the square root of the inverse capillary number (Ca^(-1/2)) based on the continuous phase, the disperse-phase flow rate was found to be unimportant.
Microchannel Emulsification : From Computational Fluid Dynamics to Predictive Analytical Model
VAN DIJKE Koen C. ; SCHROEN Karin C. P. G. H. ; BOOM Remko M.;
Food and Bioprocess Engineering Group, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
Langmuir 24 (2008), n18, p. 10107-10115, ISSN 0743-7463, CODEN LANGD5
Abstract
Emulsion droplet formation was investigated in terrace-based microchannel systems that generate droplets through spontaneous Laplace pressure driven snap-off. The droplet formation mechanism was investigated through high-speed imaging and computational fluid dynamics (CFD) simulation, and we found good agreement in the overall shape of the phases during droplet formation. An analytical model was derived from the insights that were gained from the CFD simulations, which describes the droplet diameter as a function of applied pressure. The analytical model covers the influence of both process parameters and geometry of the terrace well and can be used for fast optimization and evaluation studies.
Visualization of droplet break-up in pre-mix membrane emulsification using microfluidic devices
VAN DER ZWAN Eduard; SCHROËN Karin; VAN DIJKE Koen; BOOM Remko;
Wageningen University, Agrotechnology and Food Sciences, Food and Bioprocess Engineering Group, P.O. Box 8129, 6700EV Wageningen, The Netherlands
Colloids and surfaces. A, 277 (2006), n1-3, pp. 223-229, ISSN 0927-7757
Abstract
To investigate the break-up of emulsion droplets in pre-mix or dead-end membrane emulsification, a microscopic study was conducted in microfluidic devices. Channels with shapes such as constrictions, junctions, and combinations thereof representing ideal membrane structures where etched in silicon. Through these structures pre-mix emulsion droplets where pushed, which was recorded with high-speed video microscopy. Accumulation of droplets of the dispersed phase before and inside the pore network was found to occur under all conditions. Thus, the effective volume fraction of dispersed phase inside the pores is always high. In a brick-shaped pore structure, an optimum thickness of the layer was found. In these structures, channelling occurs below a critical pressure difference over the structure. In the channelling regime, isolated channels are active, effectively excluding action of branchings and junctions. We found three main categories of break-up mechanisms (snap-off due to localized shear, break-up due to interfacial tension effects, and break-up due to steric hindrance) and were able to quantify some. Break-up due to branchings and junctions do not seem to be essential for break-up to occur. It is, however, clear that the other phenomena (accumulation, channelling) can have major impact on the total behaviour of the system and should not be neglected.