Water (and other liquids) has an unusual property when it flows closely to some specially designed surfaces: its speed isn't equal to zero even in the layer that directly touches the wall. This means that liquid doesn't adhere to the surface, but instead slides along it. Such an effect is called hydrodynamic slip and it was first described more than 200 years ago. However, at that time it hasn't received much attention as it didn't significantly influence the cumulative liquid flow.
from Geochemistry News -- ScienceDaily http://ift.tt/2ekgML1