Direct Measurements of Hydrophobic Slippage using Double-Focus Fluorescence Cross-Correlationстатья
Статья опубликована в высокорейтинговом журнале
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:We report the results of direct measurements of velocity profiles in a microchannel with hydrophobic
and hydrophilic walls, using a new high-precision method of double-focus spatial fluorescence cross
correlation under a confocal microscope. In the vicinity of both walls the measured velocity profiles do not
go to zero by supplying a plateau of constant velocity. This apparent slip is proven to be due to a Taylor
dispersion, an augmentation by shear diffusion of nanotracers in the direction of flow. Comparing the
velocity profiles near the hydrophobic and hydrophilic walls for various conditions shows that there is a
true slip length due to hydrophobicity. This length, of the order of several tens of nanometers, is
independent of the electrolyte concentration and shear rate.