1 research outputs found
Capillary Rise in Nanopores: Molecular Dynamics Evidence for the Lucas-Washburn Equation
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 -law. For the polymer melt,
however, we find that the capillary flow exhibits a slip length ,
comparable in size with the nanotube radius . 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 .Comment: 4 pages 4 figure