Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Adhesive forces are the attractive interactions between unlike molecules. These forces are responsible for phenomena such as capillary action and the spreading of liquids on solid surfaces.
5 Must Know Facts For Your Next Test
Adhesive forces occur between different types of molecules, unlike cohesive forces which occur between like molecules.
They play a crucial role in capillary action, where liquid rises or falls in a narrow tube due to the attraction between the liquid and the tube material.
The strength of adhesive forces depends on the nature of the interacting substances; for example, water has strong adhesive forces with glass but weaker ones with non-polar surfaces like oil.
Adhesive forces are essential in various applications such as painting, gluing, and ink printing, where liquid needs to spread over or stick to a surface.
These forces can be quantified using contact angle measurements; a low contact angle indicates strong adhesive forces between the liquid and solid.
The ability of a liquid to flow in narrow spaces without external forces due to adhesive and cohesive interactions.
Contact Angle: $\theta$ is the angle formed by a liquid at the boundary where it meets a solid surface; used to quantify wetting properties influenced by adhesive forces.