adhesion

Examples of adhesion in the following topics:

• Surface Tension

  • The contact angle is measured in the liquid and depends on the relative strength of cohesive forces in the liquid and adhesive forces between the liquid and interface materials.
  • If liquid molecules are strongly attracted to the molecules of the solid surface (adhesive forces > cohesive forces), the drop will tend to spread out and the contact angle will be close to zero degrees .
  • If the cohesive forces are greater than the adhesive forces, the resulting contact angles will be large and will form a more circular drop .
  • When a water droplet forms on a leaf, the cohesive forces between the water molecules are greater than the adhesive forces between the water and leaf surface.

• Surface Tension and Capillary Action

  • Attractive forces between molecules of different types are called adhesive forces.
  • In this section we examine effects of cohesive and adhesive forces in liquids.
  • If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and the container act to lift the liquid.

• Friction: Kinetic

  • Such adhesive forces also depend on the substances the surfaces are made of, explaining, for example, why rubber-soled shoes slip less than those with leather soles.

• Molecular Transport Phenomena

  • For example, temperature and cohesive and adhesive forces all affect values of D.