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Mechanisms and control of single-step microfluidic generation of multi-core double emulsion droplets
journal contribution
posted on 2017-04-20, 15:49 authored by Seyed Ali Nabavi, Goran VladisavljevicGoran Vladisavljevic, Vasilije ManovicSingle-step generation of monodisperse multi-core double emulsion drops in three-phase glass capillary microfluidic device was investigated using a micro-particle image velocimetry (micro-PIV) system. Phase diagrams were developed to predict the number of encapsulated inner drops as a function of the capillary numbers of inner, middle and outer fluid. The maximum stable number of inner drops cores in uniform double emulsion drops was six. Starting from core/shell drops, the formation of double emulsion drops with multiple cores was achieved by decreasing the capillary number of the outer fluid and increasing the capillary number of the middle fluid. A stable continuous jet of the middle fluid loaded with inner drops was formed at high capillary numbers of the middle fluid. Empirical correlations predicting the size and generation frequency of inner drops as a function of the capillary numbers and the device geometry were developed. Dual-core double emulsion drops were used as templates for the fabrication of polymeric capsules using “on-the-fly” photopolymerisation. The capsule morphology was controlled by manipulating the stability of the inner drops through adjusting the concentration of the lipophilic surfactant in the middle fluid. At low concentration of the lipophilic surfactant, inner drops coalesced during curing and single compartment capsules with thin shells were produced from dual-core drops. The core/shell capsules produced from multi-core drops were monodispersed and larger than those produced from core/shell drops in the same device.
Funding
The authors gratefully acknowledge the financial support for this work from the UK Engineering and Physical Sciences Research Council (EPSRC) grant EP/HO29923/1.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Chemical Engineering
Published in
Chemical Engineering JournalVolume
322Pages
140 - 148Citation
NABAVI, S.A., VLADISAVLJEVIC, G.T. and MANOVIC, V., 2017. Mechanisms and control of single-step microfluidic generation of multi-core double emulsion droplets. Chemical Engineering Journal, 322, pp. 140-148.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: https://creativecommons.org/licenses/by/4.0/Acceptance date
2017-04-02Publication date
2017-04-04Copyright date
2017Notes
This article was published as Open Access by Elsevier under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence.ISSN
1385-8947Publisher version
Language
- en