Abstract
This work presents an alternative approach for visualizing and monitoring in real-time emulsification process using an optical microscope and a stroboscopic light controlled by a homemade circuit implemented in an Arduino microcontroller. The microfluidic device was built from glass tapered capillaries coaxially aligned in a co-flow configuration. The implemented optical visualization allows a clear in-situ identification of three oil-in-water emulsification regimes. The drop frequency production is determined in each case by matching the stroboscopic light frequency as integer submultiples of the frequency of the train of drops. The droplet production quality of each emulsification regime is associated with the polydispersity index of the collected emulsions. The frequency of each regime and their flow rates are related to a mathematical model that predicts the behavior of the frequencies upon the capillary number showing the applicability of the stroboscopic system to obtain qualitative information. The in situ monitoring of dripping regime varying the flow conditions enable the production and collection of emulsions with controlled drop size, which also are validated with a mathematical model.
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The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
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Acknowledgements
This work was partially funded by Consejo de la Investigación Científica, Universidad Michoacana de San Nicolás de Hidalgo (UMSNH), Research Project 2023. Luis M. Montes-de-Oca acknowledges support from the Mexican Council on Humanities, Science and Technology (CONAHCYT) for a postdoctoral fellowship.
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Montes-de-Oca, L.M., Espinosa, G. & Martínez-Torres, P. Identification of emulsification regimes in co-flow microfluidics using stroboscopic LED illumination. Microfluid Nanofluid 27, 61 (2023). https://doi.org/10.1007/s10404-023-02671-2
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DOI: https://doi.org/10.1007/s10404-023-02671-2