Nano Archive

Capillary rise in nanopores: Molecular dynamics evidence for the Lucas-Washburn equation

Dimitrov, D. I. and Milchev, A and Binder, K (2007) Capillary rise in nanopores: Molecular dynamics evidence for the Lucas-Washburn equation. PHYSICAL REVIEW LETTERS, 99 (5).

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Official URL: http://link.aps.org/doi/10.1103/PhysRevLett.99.054...

Abstract

When a capillary is inserted into a liquid, the liquid will rapidly flow into it. This phenomenon, well studied and understood on the macroscale, is investigated by molecular dynamics simulations for coarse-grained models of nanotubes. Both a simple Lennard-Jones fluid and a model for a polymer melt are considered. In both cases after a transient period (of a few nanoseconds) the meniscus rises according to a (time)(1/2) law. For the polymer melt, however, we find that the capillary flow exhibits a slip length delta, comparable in size with the nanotube radius R. We show that a consistent description of the imbibition process in nanotubes is only possible upon modification of the Lucas-Washburn law which takes explicitly into account the slip length delta. We also demonstrate that the velocity field of the rising fluid close to the interface is not a simple diffusive spreading.

Item Type:Article
Subjects:Physical Science > Nanophysics
Physical Science > Nano objects
Material Science > Nanostructured materials
ID Code:3207
Deposited By:Anuj Seth
Deposited On:14 Jan 2009 16:46
Last Modified:12 Feb 2009 17:46

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