Wetting transition of water on graphite and other surfaces

TL;DR

This paper predicts the temperature at which water transitions from non-wetting to wetting on graphite using a simple model, suggesting experimental verification and discussing similar transitions on other surfaces.

Contribution

It introduces a model predicting water's wetting transition temperature on graphite, filling a gap where such a transition has not been observed before.

Findings

Predicted T_w for water on graphite is between 350 and 500 K.

Model extends to other surfaces for wetting transition analysis.

Experimental verification of the transition is recommended.

Abstract

A wetting transition occurs when the contact angle of a liquid drop on a surface changes from a nonzero value to zero. Such a transition has never been observed for water on any solid surface. This paper discusses the value of the temperature T_w at which the transition should occur for water on graphite. A simple model, previously used for nonpolar fluids, predicts the value of $T_w$ as a function of the well-depth D of the adsorption potential. While $D$ is not well known for the case of water/graphite, the model implies that T_w is likely to fall in the range 350 to 500 K. Experimental search for this transition is warranted. Water wetting transition temperatures on other surfaces are also discussed.