Adhesion is the tendency of dissimilar particles or surfaces to cling to one another.
Dew drops adhering to a spider web
Concave meniscus is caused due to adhesion.
Diagram of various cases of cleavage, with each unique species labeled. A: γ = (1/2)W11 B: W12 = γ1 + γ2 – γ12 C: γ12 = (1/2)W121 = (1/2)W212 D: W12 + W33 – W13 – W23 = W132.
Cohesion causes water to form drops, surface tension causes them to be nearly spherical, and adhesion keeps the drops in place.
Wetting is the ability of a liquid to maintain contact with a solid surface, resulting from intermolecular interactions when the two are brought together. This happens in presence of a gaseous phase or another liquid phase not miscible with the first one. The degree of wetting (wettability) is determined by a force balance between adhesive and cohesive forces. There are two types of wetting: non-reactive wetting and reactive wetting.
Water bead on a fabric that has been made non-wetting by chemical treatment.
Figure 6: Schematic of advancing and receding contact angles
Figure 9: "Petal effect" vs. "lotus effect"
Strands of an uncharged ferrocene-substituted polymer are tethered to a hydrophobic silica surface. Oxidation of the ferrocenyl groups produces a hydrophilic surface due to electrostatic attractions between the resulting charges and the polar solvent.
