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Probing the nanohydrodynamics at liquid-solid interfaces using thermal motion

L. Joly·C. Ybert·L. Bocquet
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Abstract

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.

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L. Joly, C. Ybert, L. Bocquet. 2005-07-02. Probing the nanohydrodynamics at liquid-solid interfaces using thermal motion. https://doi.org/10.1103/physrevlett.96.046101

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