1-s2.0-S0021979717306513-main (1).pdf (2.07 MB)
Prediction and control of drop formation modes in microfluidic generation of double emulsions by single-step emulsification
journal contribution
posted on 2017-06-08, 10:25 authored by Seyed Ali Nabavi, Goran VladisavljevicGoran Vladisavljevic, Monalie Bandulasena, Omid Arjmandi-Tash, Vasilije ManovicHypothesis - 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 ScienceVolume
505Pages
315–324Citation
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 AuthorsVersion
- 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
2017-05-30Publication date
2017-06-01Copyright date
2017Notes
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
1095-7103Publisher version
Language
- en