7 research outputs found
Probing the nanohydrodynamics at liquid-solid interfaces using thermal motion
We report on a new method to characterize nano-hydrodynamic properties at the
liquid/solid interface relying solely on the measurement of the thermal motion
of confined colloids. Using Fluorescence Correlation Spectroscopy (FCS) to
probe the diffusion of the colloidal tracers, this optical technique
--equivalent in spirit to the microrheology technique used for bulk
properties-- is able to achieve nanometric resolution on the slip length
measurement. It confirms the no-slip boundary condition on wetting surfaces and
shows a partial slip b=18 +/- 5 nm on non-wetting ones. Moreover, in the
absence of external forcing, we do not find any evidence for large nano-bubble
promoted slippage on moderately rough non-wetting surfaces.Comment: 4 pages, 3 figure
Diffusion in pores and its dependence on boundary conditions
We study the influence of the boundary conditions at the solid liquid
interface on diffusion in a confined fluid. Using an hydrodynamic approach, we
compute numerical estimates for the diffusion of a particle confined between
two planes. Partial slip is shown to significantly influence the diffusion
coefficient near a wall. Analytical expressions are derived in the low and high
confinement limits, and are in good agreement with numerical results. These
calculations indicate that diffusion of tagged particles could be used as a
sensitive probe of the solid-liquid boundary conditions.Comment: soumis \`a J.Phys. Cond. Matt. special issue on "Diffusion in
Liquids, Polymers, Biophysics and Chemical Dynamics
Diffusion in pores and its dependence on boundary conditions
Abstract We study the influence of the boundary conditions at the solid-liquid interface on diffusion in a confined fluid. Using a hydrodynamic approach, we compute numerical estimates for the diffusion of a particle confined between two planes. Partial slip is shown to significantly influence the diffusion coefficient near a wall. Analytical expressions are derived in the low and high confinement limits, and are in good agreement with numerical results. These calculations indicate that diffusion of tagged particles could be used as a sensitive probe of the solid-liquid boundary conditions
Molecular views of electrokinetic phenomena
D.M. Huang, L. Joly, C. Cottin-Bizonne, C. Ybert, E. Trizac and L. Bocquethttp://trove.nla.gov.au/work/3872575