Glossary of surface technology
Cohesion
Bonding force between the atoms or molecules of a medium by mutual attraction. A high cohesion causes a high resistance against deformation of the medium. When a liquid is applied to a substrate, high cohesion causes the liquid to lie on the substrate as an almost spherical drop (flattened by gravitational force). When, on the other hand, the adhesive force with which the molecules of substrate and surface attract each other, is greater than the cohesion force, the liquid will spread on the surface.