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Mechanisms and control of single-step microfluidic generation of multi-core double emulsion droplets

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journal contribution
posted on 20.04.2017, 15:49 by Seyed Ali Nabavi, Goran VladisavljevicGoran Vladisavljevic, Vasilije Manovic
Single-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 Journal

Volume

322

Pages

140 - 148

Citation

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

02/04/2017

Publication date

2017-04-04

Copyright date

2017

Notes

This article was published as Open Access by Elsevier under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence.

ISSN

1385-8947

Language

en