[Terminology] Wetting phenomena
Wetting phenomena include three classes: (1), adhesion; (2), immersion; (3), spreading.
The process which a solid, previously in contact with a gaseous phase, is brought into contact with a liquid phase.
Typical adhesion wetting phenomena, such as: when it rains, clothes were wet.
The process which a solid is immersed into a liquid.
Typical immersion wetting phenomena, such as: the clothes washing process.
The process which a liquid spontaneously forms a well-distributed thin liquid layer on a solid.
Typical spreading phenomena, such as: photographic film production process.
In fact, a system which spreading can spontaneously form, adhesion and immersion wetting can occur inevitably.