|WikiProject Physics / Fluid Dynamics||(Rated Start-class, Mid-importance)|
Hmmm... rather technical. Needs pictures, i guess... I might make one, e.g. if then it's wettable...(that's right, right?)
Spreading is not the same as wetting. Wetting equilibria is the term that can refer to 4 different things, Spreading wetting, Adhesional Wetting, Immersional Wetting, and Adsorption and Wetting. (M.J. Rosen "Surfactants and Interfacial Phenomena," Wiley-Interscience 3rd ed (2004) chapter 6
The phrase saying that spreading coefficient more than 0 the wetting occurs is quite misleading because it may refer to other type of wetting so using the "spontaneous spreading" term in this case is more appropriate.
The current article has been obviously written by someone who knows the subject very well but it seems to me that it does not cover all relevant aspects of the term "dewetting". As the previous user pointed out, spreading is not the same as wetting. Still, I feel that both phenomena should be explained together in one article and not separately.
I would start the article somehow like that:
In fluid mechanics, the term spreading or the term dewetting refers to a certain property of a system with usually has three distinct phases, e.g. liquid/gas/solid or liquid/liquid/solid. E.g., it is said that a liquid spreads on another phase if the common interfaces increases in time. If the common interface is decreasing in time one speaks of dewetting.
The most important driving forces for dewetting or spreading are surface tension and gravity.
For a liquid/solid/gas system, the tendency to wet or spread is usually characterized by the spreading coefficient or the contact angle.
Does somebody like that approach or even has a more general view on dewetting and spreading?
In my opinion, the article on dewetting should be improved (perhaps one could include a sketch), the references should be chosen more carefully. Finally, as long as it is a very short article it should be moved to surface tension. In addition one should include some (more?) examples of systems (liquid/solid/gas or liquid/liquid/gas), which spread/wet or dewet.