Characterization of wetting in the lateral and normal directions

In the direction parallel (lateral) to a surface, wetting is usually described by the lateral retention force, whereas in the normal direction it is usually described by the work of adhesion (Young-Dupre equation). In this talk, we will present an energy description of wetting in the lateral direction by introducing the advancing, receding, and sliding works of adhesion. We will also compare three different theoretical proposals to describe the normal force of adhesion and their relationship with the Young-Dupre equation. Finally, we will confront the predictions of those theoretical proposals with the results of a recent experiment on the work of adhesion.