Long-term stability of droplet production by microchannel (step) emulsification in microfluidic silicon chips with large number of terraced microchannels.pdf (2.44 MB)
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Long-term stability of droplet production by microchannel (step) emulsification in microfluidic silicon chips with large number of terraced microchannels

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journal contribution
posted on 26.09.2017, 10:29 by Goran VladisavljevicGoran Vladisavljevic, Ekanem E. Ekanem, Zilin Zhang, Nauman Khalid, Isao Kobayashi, Mitsutoshi Nakajima
A long-term production stability of oil-in-water emulsions by microchannel (step) emulsification was investigated using two cross flow silicon chips consisting of 540 or 1,850 microchannels fabricated on 10 parallel terraces. Each terrace was 9.54 mm long and consisted of 54 channels with a depth of 5 µm and a width of 18 µm (chip 1) or 185 channels with a depth of 4 µm and a width of 8 µm (chip 2). The dispersed phase was a mixture of 2 wt% polycaprolactone (PCL) and 1 wt% poly(d,l-lactic) acid (PLA) dissolved in dichloromethane and the continuous phase was 2 wt% poly(vinyl alcohol). After solvent evaporation, the droplets were transformed into highly uniform composite polymer particles with an average diameter of 8.8 or 4.9 µm. The percentages of active channels, droplet sizes and droplet generation frequencies at individual terraces were investigated in both chips to reveal any flow maldistribution. After 6 h of production in chip 1, overall 95% of the channels produced droplets and the percentage of active channels on each terrace was at least 91%. The percentage of active channels decreased by decreasing the size of the channels. The mean droplet size varied negligibly across individual terraces over 7 h. Slightly higher droplet generation frequencies and smaller percentages of active channels were observed at central terraces. The droplet generation frequencies at the channels located close to each other were similar, indicating that droplet formation dynamics was coupled. The droplet size was not affected by the dispersed phase flow rate.

Funding

The authors gratefully acknowledge the financial support from the JSPS-UK BRIDGE Fellowship (BR 130302) awarded to Dr Vladisavljevic.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Chemical Engineering

Published in

Chemical Engineering Journal

Volume

333

Pages

380-391

Citation

VLADISAVLJEVIC, G.T. ...et al., 2017. Long-term stability of droplet production by microchannel (step) emulsification in microfluidic silicon chips with large number of terraced microchannels. Chemical Engineering Journal, 333, pp. 380-391.

Publisher

© Elsevier

Version

AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Acceptance date

23/09/2017

Publication date

2017-09-26

Copyright date

2018

Notes

This paper was published in the journal Chemical Engineering Journal and the definitive published version is available at https://doi.org/10.1016/j.cej.2017.09.141.

ISSN

1385-8947

Language

en