A Langevin model for fluctuating contact angle behaviour parametrised using molecular dynamics
File(s)
Accepted version
Author(s)
Smith, ER
Müller, EA
Craster, RV
Matar, OK
Type
Journal Article
Abstract
Molecular dynamics simulations are employed to develop a theoretical model to predict the fluid-solid contact angle as a function of wall-sliding speed incorporating thermal fluctuations. A liquid bridge between counter-sliding walls is studied, with liquid-vapour interface-tracking, to explore the impact of wall-sliding speed on contact angle. The behaviour of the macroscopic contact angle varies linearly over a range of capillary numbers beyond which the liquid bridge pinches off, a behaviour supported by experimental results. Nonetheless, the liquid bridge provides an ideal test case to study molecular scale thermal fluctuations, which are shown to be well described by Gaussian distributions. A Langevin model for contact angle is parametrised to incorporate the mean, fluctuation and auto-correlations over a range of sliding speeds and temperatures. The resulting equations can be used as a proxy for the fully-detailed molecular dynamics simulation allowing them to be integrated within a continuum-scale solver.
Date Issued
2016-12-28
Date Acceptance
2016-11-08
Citation
Soft Matter, 2016, 12 (48), pp.9604-9615
ISSN
1744-6848
Publisher
Royal Society of Chemistry
Start Page
9604
End Page
9615
Journal / Book Title
Soft Matter
Volume
12
Issue
48
Copyright Statement
© 2016 Royal Society of Chemistry
Identifier
http://www.ncbi.nlm.nih.gov/pubmed/27853798
Subjects
Chemical Physics
03 Chemical Sciences
09 Engineering
02 Physical Sciences
Publication Status
Published
Coverage Spatial
England
Date Publish Online
2016-11-09