Definition - What does Wettability mean?
The wettability of a solid surface or fabric is defined as the ability of the surface to hold contact with a liquid. In other words, it’s the surface’s ability to be wetted by the liquid. Wettability is determined by the equilibrium of the surface energy between the solid, liquid and air (or other gas). Wettability is an important property when specifying coatings.
Corrosionpedia explains Wettability
When a liquid drop falls on a solid surface, the liquid spreads across the surface until it forms a shape where the forces between the liquid, solid and air are in equilibrium. If a surface has a high wettability (e.g., glass) the liquid will spread completely. In contrast, if a surface has low wettability, the droplet will retain its shape (such as the case with some plastics).
Surfaces with high wettability are termed hydrophilic, and surfaces with low wettability are termed hydrophobic. This property has become the center of many materials science studies for the development of new and advanced materials, particularly in the fields of nanotechnology and nanoscience.