Spreading of fluids in narrow channels
Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)Abstract
During the last few years, the emerging field of nanofluidics has
attracted increasing experimental and theoretical interest.
One of the present theoretical challenges is the good understanding
of the influence of the microscopic, atomistic details of the
fluid and of the confining solid on the dynamics of transport through
nanoscale pipes/channels.
In this paper we present a stochastic, microscopic model for the
spreading of fluids in a narrow, slit-like channel connected
at its ends with macroscopic reservoirs of particles maintained at
different chemical potentials in the case in which a significant
wall-fluid interaction is present. Using numerical simulations
combined with a mean-field analysis of the master-equation corresponding
to the microscopic dynamics, we show that the time evolution and the
steady state of the system are well-described by a non-linear diffusion
equation with a density dependent diffusion coefficient.
A number of extensions, including the case of spatially varying wall-fluid
interactions and that of external driving forces acting on the fluid
particles, are also discussed.