Issue 21, 2021

Propelling microdroplets generated and sustained by liquid–liquid phase separation in confined spaces

Abstract

Flow transport in confined spaces is ubiquitous in technological processes, ranging from separation and purification of pharmaceutical ingredients by microporous membranes and drug delivery in biomedical treatment to chemical and biomass conversion in catalyst-packed reactors and carbon dioxide sequestration. In this work, we suggest a distinct pathway for enhanced liquid transport in a confined space via propelling microdroplets. These microdroplets can form spontaneously from localized liquid–liquid phase separation as a ternary mixture is diluted by a diffusing poor solvent. High speed images reveal how the microdroplets grow, break up and propel rapidly along the solid surface, with a maximal velocity up to ∼160 μm s−1, in response to a sharp concentration gradient resulting from phase separation. The microdroplet propulsion induces a replenishing flow between the walls of the confined space towards the location of phase separation, which in turn drives the mixture out of equilibrium and leads to a repeating cascade of events. Our findings on the complex and rich phenomena of propelling droplets suggest an effective approach to enhanced flow motion of multicomponent liquid mixtures within confined spaces for time effective separation and smart transport processes.

Graphical abstract: Propelling microdroplets generated and sustained by liquid–liquid phase separation in confined spaces

Supplementary files

Article information

Article type
Paper
Submitted
12 feb 2021
Accepted
16 apr 2021
First published
22 apr 2021

Soft Matter, 2021,17, 5362-5374

Propelling microdroplets generated and sustained by liquid–liquid phase separation in confined spaces

X. Zhang, J. B. You, G. F. Arends, J. Qian, Y. Chen, D. Lohse and J. M. Shaw, Soft Matter, 2021, 17, 5362 DOI: 10.1039/D1SM00231G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements