colloids-02-00056-v2 (2).pdf (2.78 MB)
Sessile droplets on deformable substrates
journal contribution
posted on 2019-08-16, 10:01 authored by Gulraiz Ahmed, Nektaria Koursari, Anna TrybalaAnna Trybala, Victor StarovWetting of deformable substrates has gained significant interest over the past decade due to a multiplicity of industrial and biological applications. Technological advances in the area of interfacial science have given rise to the ability to capture interfacial behavior between a liquid droplet and an elastic substrate. Researchers have developed several theories to explain the interaction between the two phases and describe the process of wetting of deformable/soft substrates. A summary of the most recent advances on static wetting of deformable substrates is given in this review. It is demonstrated that action of surface forces (disjoining/conjoining pressure) near the apparent three-phase contact line should be considered. Any consideration of equilibrium droplets on deformable (as well as on non-deformable) substrates should be based on consideration of the excess free energy of the system. The equilibrium shapes of both droplet and deformable substrate should correspond to the minimum of the excess free energy of the system. It has never been considered in the literature that the obtained equilibrium profiles must satisfy sufficient Jacobi’s condition. If Jacobi’s condition is not satisfied, it is impossible to claim that the obtained solution really corresponds to equilibrium. In recently published studies, equilibrium of droplets on deformable substrates: (1) provided a solution that corresponds to the minimum of the excess free energy; and (2) the obtained solution satisfies the Jacobi’s condition. Based on consideration of disjoining/conjoining pressure acting in the vicinity of the apparent three-phase contact line, the hysteresis of contact angle of sessile droplets on deformable substrates is considered. It is shown that both advancing and receding contact angles decrease as the elasticity of the substrate is increased and the effect of disjoining/conjoining pressure is discussed. Fluid inside the droplet partially wets the deformable substrate. It is shown that just these forces coupled with the surface elasticity determine the deformation of the deformable substrates.
Funding
CoWet Marie Curie EU project
MAP EVAPORATION project
European Space Agency
Proctor & Gamble, Brussels
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Chemical Engineering
Published in
Colloids and InterfacesVolume
2Issue
4Publisher
MDPI AGVersion
- VoR (Version of Record)
Rights holder
© the AuthorsPublisher statement
This is an Open Access Article. It is published by MDPI under the Creative Commons Attribution 4.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/Acceptance date
2018-11-02Publication date
2018-11-06Copyright date
2018Notes
This article belongs to the Special Issue Selected Papers from the 16th Conference of the International Association of Colloid and Interface Scientists (IACIS 2018)eISSN
2504-5377Publisher version
Language
- en
Depositor
Mrs Nektaria KoursariArticle number
56Usage metrics
Categories
No categories selectedLicence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC