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Title: Beyond-Cassie Mode of Wetting and Local Contact Angles of Droplets on Checkboard-Patterned Surfaces

Abstract

Droplet wetting and distortion on flat surfaces with heterogeneous wettability are studied using the 3D Shan–Chen pseudopotential multiphase lattice Boltzmann model (LBM). The contact angles are compared with the Cassie mode, which predicts an apparent contact angle for flat surfaces with different wetting properties, where the droplet size is large compared to the size of the heterogeneity. The surface studied consists in a regular checkboard pattern with two different Young’s contact angles (hydrophilic and hydrophobic) and equal surface fraction. The droplet size and patch size of the checkboard are varied beyond the limit where Cassie’s equation is valid. A critical ratio of patch size to droplet radius is found below which the apparent contact angle follows the Cassie mode. Above the critical value, the droplet shape changes from a spherical cap to a more distorted form, and no single contact angle can be determined. The local contact angles are found to vary along the contact line between minimum and maximum values. The droplet is found to wet preferentially the hydrophilic region, and the wetted area fraction of the hydrophilic region increases quasi-linearly with the ratio between patch and droplet sizes. We propose a new equation beyond the critical ratio, definingmore » an equivalent contact angle, where the wetted area fractions are used as weighting coefficients for the maximum and minimum local contact angles. This equivalent contact angle is found to equal Cassie’s contact angle.« less

Authors:
 [1];  [2];  [3];  [4]
+ Show Author Affiliations
  1. Swiss Federal Inst. of Technology in Zürich (ETH Zürich) (Switzerland). Chair of Building Physics; Swiss Federal Lab. for Materials Science and Technology (Empa), Dübendorf (Switzerland). Lab. of Multiscale Studies in Building Physics
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Xi’an Jiaotong Univ. (China). Key Lab. of Thermo-Fluid Science and Engineering of MOE. School of Energy and Power Engineering
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  4. Swiss Federal Lab. for Materials Science and Technology (Empa), Dübendorf (Switzerland). Lab. of Multiscale Studies in Building Physics
Publication Date:
Research Org.:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Swiss Federal Inst. of Technology in Zürich (ETH Zürich) (Switzerland); Swiss Federal Lab. for Materials Science and Technology (Empa), Dübendorf (Switzerland)
Sponsoring Org.:
USDOE; LANL Laboratory Directed Research and Development (LDRD) Program; Swiss National Science Foundation (SNSF)
OSTI Identifier:
1514943
Report Number(s):
LA-UR-17-24801
Journal ID: ISSN 0743-7463
Grant/Contract Number:  
89233218CNA000001; 200021-143651
Resource Type:
Accepted Manuscript
Journal Name:
Langmuir
Additional Journal Information:
Journal Volume: 33; Journal Issue: 24; Journal ID: ISSN 0743-7463
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Carmeliet, Jan, Chen, Li, Kang, Qinjun, and Derome, Dominique. Beyond-Cassie Mode of Wetting and Local Contact Angles of Droplets on Checkboard-Patterned Surfaces. United States: N. p., 2017. Web. doi:10.1021/acs.langmuir.7b01471.
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Carmeliet, Jan, Chen, Li, Kang, Qinjun, & Derome, Dominique. Beyond-Cassie Mode of Wetting and Local Contact Angles of Droplets on Checkboard-Patterned Surfaces. United States. https://doi.org/10.1021/acs.langmuir.7b01471
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Carmeliet, Jan, Chen, Li, Kang, Qinjun, and Derome, Dominique. Wed . "Beyond-Cassie Mode of Wetting and Local Contact Angles of Droplets on Checkboard-Patterned Surfaces". United States. https://doi.org/10.1021/acs.langmuir.7b01471. https://www.osti.gov/servlets/purl/1514943.
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@article{osti_1514943,
title = {Beyond-Cassie Mode of Wetting and Local Contact Angles of Droplets on Checkboard-Patterned Surfaces},
author = {Carmeliet, Jan and Chen, Li and Kang, Qinjun and Derome, Dominique},
abstractNote = {Droplet wetting and distortion on flat surfaces with heterogeneous wettability are studied using the 3D Shan–Chen pseudopotential multiphase lattice Boltzmann model (LBM). The contact angles are compared with the Cassie mode, which predicts an apparent contact angle for flat surfaces with different wetting properties, where the droplet size is large compared to the size of the heterogeneity. The surface studied consists in a regular checkboard pattern with two different Young’s contact angles (hydrophilic and hydrophobic) and equal surface fraction. The droplet size and patch size of the checkboard are varied beyond the limit where Cassie’s equation is valid. A critical ratio of patch size to droplet radius is found below which the apparent contact angle follows the Cassie mode. Above the critical value, the droplet shape changes from a spherical cap to a more distorted form, and no single contact angle can be determined. The local contact angles are found to vary along the contact line between minimum and maximum values. The droplet is found to wet preferentially the hydrophilic region, and the wetted area fraction of the hydrophilic region increases quasi-linearly with the ratio between patch and droplet sizes. We propose a new equation beyond the critical ratio, defining an equivalent contact angle, where the wetted area fractions are used as weighting coefficients for the maximum and minimum local contact angles. This equivalent contact angle is found to equal Cassie’s contact angle.},
doi = {10.1021/acs.langmuir.7b01471},
journal = {Langmuir},
number = 24,
volume = 33,
place = {United States},
year = {Wed May 31 00:00:00 EDT 2017},
month = {Wed May 31 00:00:00 EDT 2017}
}
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Journal Article:
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Publisher's Version of Record
https://doi.org/10.1021/acs.langmuir.7b01471
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Cited by: 32 works
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Figures / Tables:

Figure 1 Figure 1: Schematic of the computational domain showing a droplet on a checkboard-patterned heterogeneous surface with patch size $a$. The patches are alternating hydrophilic (magenta) and hydrophobic (green).
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Works referenced in this record:

Wetting and spreading
journal, May 2009

III. An essay on the cohesion of fluids
journal, January 1805

  • Young, Thomas
  • Philosophical Transactions of the Royal Society of London, Vol. 95, p. 65-87
  • DOI: 10.1098/rstl.1805.0005

The rigorous derivation of Young, Cassie–Baxter and Wenzel equations and the analysis of the contact angle hysteresis phenomenon
journal, January 2008

How Wenzel and Cassie Were Wrong
journal, March 2007

Reply to “Comment on How Wenzel and Cassie Were Wrong by Gao and McCarthy”
journal, November 2007

  • Gao, Lichao; McCarthy, Thomas J.
  • Langmuir, Vol. 23, Issue 26, p. 13243-13243
  • DOI: 10.1021/la703004v

When Wenzel and Cassie Are Right: Reconciling Local and Global Considerations
journal, January 2009

Cassie and Wenzel:  Were They Really So Wrong?
journal, June 2007

The modified Cassie’s equation and contact angle hysteresis
journal, August 2012

Wetting of textured surfaces
journal, July 2002

  • Bico, José; Thiele, Uwe; Quéré, David
  • Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 206, Issue 1-3, p. 41-46
  • DOI: 10.1016/S0927-7757(02)00061-4

Contact Angles and Hysteresis on Surfaces with Chemically Heterogeneous Islands
journal, April 2003

Advancing contact lines on chemically patterned surfaces
journal, January 2004

Efficient modelling of droplet dynamics on complex surfaces
journal, February 2016

  • Karapetsas, George; Chamakos, Nikolaos T.; Papathanasiou, Athanasios G.
  • Journal of Physics: Condensed Matter, Vol. 28, Issue 8
  • DOI: 10.1088/0953-8984/28/8/085101

Beyond Cassie equation: Local structure of heterogeneous surfaces determines the contact angles of microdroplets
journal, July 2014

  • Zhang, Bo; Wang, Jianjun; Liu, Zhiping
  • Scientific Reports, Vol. 4, Issue 1
  • DOI: 10.1038/srep05822

Drop dynamics on chemically patterned surfaces
journal, March 2006

Modeling Contact Angle Hysteresis on Chemically Patterned and Superhydrophobic Surfaces
journal, May 2007

  • Kusumaatmaja, H.; Yeomans, J. M.
  • Langmuir, Vol. 23, Issue 11
  • DOI: 10.1021/la063218t

Lattice Boltzmann Method for Fluid Flows
journal, January 1998

Simulation of nonideal gases and liquid-gas phase transitions by the lattice Boltzmann equation
journal, April 1994

Equations of state in a lattice Boltzmann model
journal, April 2006

  • Yuan, Peng; Schaefer, Laura
  • Physics of Fluids, Vol. 18, Issue 4
  • DOI: 10.1063/1.2187070

A critical review of the pseudopotential multiphase lattice Boltzmann model: Methods and applications
journal, September 2014

On equations of state in a lattice Boltzmann method
journal, September 2009

  • Kupershtokh, A. L.; Medvedev, D. A.; Karpov, D. I.
  • Computers & Mathematics with Applications, Vol. 58, Issue 5
  • DOI: 10.1016/j.camwa.2009.02.024

Low-bond axisymmetric drop shape analysis for surface tension and contact angle measurements of sessile drops
journal, July 2010

  • Stalder, Aurélien F.; Melchior, Tobias; Müller, Michael
  • Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 364, Issue 1-3
  • DOI: 10.1016/j.colsurfa.2010.04.040
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    Droplets on chemically patterned surface: A local free-energy minima analysis
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    Internal-Flow-Mediated, Tunable One-dimensional Cassie-to-Wenzel Wetting Transition on Superhydrophobic Microcavity Surfaces during Evaporation
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    • Pendyala, Prashant; Kim, Hong Nam; Grewal, Harpreet S.
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