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Prediction and control of drop formation modes in microfluidic generation of double emulsions by single-step emulsification

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journal contribution
posted on 2017-06-08, 10:25 authored by Seyed Ali Nabavi, Goran VladisavljevicGoran Vladisavljevic, Monalie Bandulasena, Omid Arjmandi-Tash, Vasilije Manovic
Hypothesis - Predicting formation mode of double emulsion drops in microfluidic emulsification is crucial for controlling the drop size and morphology. Experiments and modelling - A three-phase Volume of Fluid-Continuum Surface Force (VOF–CSF) model was developed, validated with analytical solutions, and used to investigate drop formation in different regimes. Experimental investigations were done using a glue-free demountable glass capillary device with a true axisymmetric geometry, capable of readjusting the distance between the two inner capillaries during operation. Findings - A non-dimensional parameter (ζ) for prediction of double emulsion formation mode as a function of the capillary numbers of all fluids and device geometry was developed and its critical values were determined using simulation and experimental data. At logζ > 5.7, drops were formed in dripping mode; the widening jetting occurred at 5 < logζ < 5.7; while the narrowing jetting was observed at logζ < 5. The ζ criterion was correlated with the ratio of the breakup length to drop diameter. The transition from widening to narrowing jetting was achieved by increasing the outer fluid flow rate at the high capillary number of the inner fluid. The drop size was reduced by reducing the distance between the two inner capillaries and the minimum drop size was achieved when the distance between the capillaries was zero.

Funding

The authors gratefully acknowledge the financial support for this work received from the EPSRC grant EP/HO29923/1.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Chemical Engineering

Published in

Journal of Colloid and Interface Science

Volume

505

Pages

315–324

Citation

NABAVI, S.A. ... et al, 2017. Prediction and control of drop formation modes in microfluidic generation of double emulsions by single-step emulsification. Journal of Colloid and Interface Science, 505, pp. 315–324.

Publisher

Elsevier © The Authors

Version

  • VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/

Acceptance date

2017-05-30

Publication date

2017-06-01

Copyright date

2017

Notes

This is an Open Access Article. It is published by Elsevier under the Creative Commons Attribution 4.0 International Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/

ISSN

1095-7103

Language

  • en