Layering and position-dependent diffusive dynamics of confined fluids.
We study the diffusive dynamics of a hard-sphere fluid confined between parallel smooth hard walls. The position-dependent diffusion coefficient normal to the walls is larger in regions of high local packing density. High density regions also have the largest available volume, consistent with the fast local diffusivity. Indeed, local and global diffusivities as a function of the Widom insertion probability approximately collapse onto a master curve. Parallel and average normal diffusivities are strongly coupled at high densities and deviate from bulk fluid behavior.
Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA. jeetain@helix.nih.gov
Jeetain
J
Mittal
Thomas M
TM
Truskett
Jeffrey R
JR
Errington
Gerhard
G
Hummer
D003102:Colloids; D003198:Computer Simulation; D004058:Diffusion; D008390:Markov Chains; D008956:Models, Chemical
D003102:Colloids