Impact of droplets on liquid films in the presence of surfactant
File(s)
Accepted version
Author(s)
Che, Zhizhao
Matar, Omar K
Type
Journal Article
Abstract
The impact of droplets on liquid films is ubiquitous in natural and industrial processes, and surfactants can significantly alter the impact process by changing the local surface tension. Here we study the impact of droplets on liquid films in the presence of surfactant using high-speed photography, and reveal the flow pattern by dye-tracing. The effects of the droplet size and speed, and the initial film thickness on the impact process are elucidated. The results show that the flow is significantly affected by adding surfactant to the droplet, the liquid film, or to both phases. In particular, the film dye patterns form concentric circles and flower-shaped structures at low and high droplet Weber numbers, respectively. We also show how surfactant-induced Marangoni stresses modify these flow patterns, and alter the characteristics of the phenomena associated with the impact process, such as the propagation of capillary waves, the evolution of the crown, and the formation of secondary droplets. During the impact of surfactant droplets on thin water films, the Marangoni stresses can be sufficiently strong so as to drive film dewetting.
Date Issued
2017-08-03
Date Acceptance
2017-07-21
Citation
Langmuir, 2017, 33 (43), pp.12140-12148
ISSN
0743-7463
Publisher
American Chemical Society
Start Page
12140
End Page
12148
Journal / Book Title
Langmuir
Volume
33
Issue
43
Copyright Statement
© 2017 American Chemical Society
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000414383300035&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Physical Sciences
Technology
Chemistry, Multidisciplinary
Chemistry, Physical
Materials Science, Multidisciplinary
Chemistry
Materials Science
SOLID-SURFACE
DYNAMICS
DROPS
COALESCENCE
INTERFACES
EVOLUTION
Publication Status
Published