What does adhesion refer to in the context of molecular interactions?

Adhesion refers specifically to the attractive forces that occur between unlike materials when they come into contact with each other. This concept is crucial in various scientific fields, including materials science and biology, as it determines how different substances interact at the molecular level.

For instance, adhesion is demonstrated when water molecules cling to glass surfaces, as the water molecules are attracted to the polar molecules in the glass, resulting in a phenomenon that can be observed in everyday life, such as water droplets forming on a window. The strength of adhesion plays a significant role in processes like capillary action, where liquid rises in a narrow space against the force of gravity due to the adhesive forces between the liquid and the surrounding material.

Understanding adhesion is important for a variety of applications, from designing better adhesives and coatings to predicting the behavior of liquids in different environments.