Acoustic suppression of the coffee-ring effect
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Author(s)
Type
Journal Article
Abstract
We study the influence of acoustic fields on the evaporative self-assembly of solute particles suspended inside sessile droplets of complex fluids. The self-assembly process often results in an undesirable ring-like heterogeneous residue, a phenomenon known as the coffee-ring effect. Here we show that this ring-like self-assembly can be controlled acoustically to form homogeneous disc-like or concentrated spot-like residues. The principle of our method lies in the formation of dynamic patterns of particles in acoustically excited droplets, which inhibits the evaporation-driven convective transport of particles towards the contact line. We elucidate the mechanisms of this pattern formation and also obtain conditions for the suppression of the coffee-ring effect. Our results provide a more general solution to suppress the coffee-ring effect without any physiochemical modification of the fluids, the particles or the surface, thus potentially useful in a broad range of industrial and analytical applications that require homogenous solute depositions.
Date Issued
2015-07-20
Date Acceptance
2015-07-17
Citation
Soft Matter, 2015, 11 (36), pp.7207-7213
ISSN
1744-6848
Publisher
Royal Society of Chemistry
Start Page
7207
End Page
7213
Journal / Book Title
Soft Matter
Volume
11
Issue
36
Copyright Statement
This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
License URL
Subjects
Science & Technology
Physical Sciences
Technology
Chemistry, Physical
Materials Science, Multidisciplinary
Physics, Multidisciplinary
Polymer Science
Chemistry
Materials Science
Physics
CONTACT LINE DEPOSITS
SURFACE
REVERSES
DROPLET
WAVES
FLOW
Acoustics
Solutions
Chemical Physics
03 Chemical Sciences
09 Engineering
02 Physical Sciences
Publication Status
Published