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dc.contributor.authorCheng, Sen_US
dc.contributor.authorRobbins, MOen_US
dc.coverage.spatialUnited Statesen_US
dc.date.accessioned2017-02-25T19:34:22Z
dc.date.available2017-02-25T19:34:22Z
dc.date.issued2014-06en_US
dc.identifier.urihttp://hdl.handle.net/10919/75162
dc.description.abstractMolecular dynamics simulations are used to study the capillary adhesion from a nonvolatile liquid meniscus between a spherical tip and a flat substrate. The atomic structure of the tip, the tip radius, the contact angles of the liquid on the two surfaces, and the volume of the liquid bridge are varied. The capillary force between the tip and substrate is calculated as a function of their separation h. The force agrees with continuum predictions based on macroscopic theory for h down to ∼5 to 10 nm. At smaller h, the force tends to be less attractive than predicted and has strong oscillations. This oscillatory component of the capillary force is completely missed in the macroscopic theory, which only includes contributions from the surface tension around the circumference of the meniscus and the pressure difference over the cross section of the meniscus. The oscillation is found to be due to molecular layering of the liquid confined in the narrow gap between the tip and substrate. This effect is most pronounced for large tip radii and/or smooth surfaces. The other two components considered by the macroscopic theory are also identified. The surface tension term, as well as the meniscus shape, is accurately described by the macroscopic theory for h down to ∼1 nm, but the capillary pressure term is always more positive than the corresponding continuum result. This shift in the capillary pressure reduces the average adhesion by a factor as large as 2 from its continuum value and is found to be due to an anisotropy in the pressure tensor. The component in the plane of the substrate is consistent with the capillary pressure predicted by the macroscopic theory (i.e., the Young-Laplace equation), but the normal pressure that determines the capillary force is always more positive than the continuum counterpart.en_US
dc.format.extent062402 - ? page(s)en_US
dc.languageengen_US
dc.relation.urihttp://www.ncbi.nlm.nih.gov/pubmed/25019789en_US
dc.subjectAdhesivenessen_US
dc.subjectCapillary Actionen_US
dc.subjectComputer Simulationen_US
dc.subjectHydrodynamicsen_US
dc.subjectModels, Chemicalen_US
dc.subjectMolecular Dynamics Simulationen_US
dc.subjectNanoparticlesen_US
dc.subjectRheologyen_US
dc.subjectShear Strengthen_US
dc.subjectStress, Mechanicalen_US
dc.titleCapillary adhesion at the nanometer scale.en_US
dc.typeArticle - Refereed
dc.description.versionPublished (Publication status)en_US
dc.title.serialPhys Rev E Stat Nonlin Soft Matter Physen_US
dc.identifier.doihttps://doi.org/10.1103/PhysRevE.89.062402
dc.type.otherResearch Support, U.S. Gov't, Non-P.H.S.en_US
dc.identifier.volume89en_US
dc.identifier.issue6en_US
dc.identifier.eissn1550-2376en_US
pubs.organisational-group/Virginia Tech
pubs.organisational-group/Virginia Tech/All T&R Faculty
pubs.organisational-group/Virginia Tech/Science
pubs.organisational-group/Virginia Tech/Science/COS T&R Faculty
pubs.organisational-group/Virginia Tech/Science/Physics


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