Adhézie

Adhézie refers to the tendency of dissimilar particles or surfaces to cling to one another. This phenomenon is distinct from cohesion, which describes the attraction between like particles. Adhézie is a surface effect, meaning it occurs at the interface between two different materials. The strength of adhézie depends on factors such as the chemical composition of the surfaces, their physical properties like roughness and cleanliness, and the presence of any intervening substances.

Common examples of adhézie include water droplets sticking to a glass surface, paint adhering to a wall, or adhesive tape bonding to paper. The underlying mechanisms of adhézie can be attributed to various intermolecular forces, such as van der Waals forces, electrostatic interactions, and hydrogen bonding. In some cases, chemical bonding can also play a significant role, leading to very strong adhézie.

Understanding adhézie is crucial in many fields. In engineering, it is vital for the design of coatings, adhesives, and composite materials. In biology, adhézie plays a role in cell-cell interactions and the attachment of microorganisms to surfaces. In everyday life, it explains why dust sticks to furniture or why shoes grip the ground. Efforts to increase or decrease adhézie are common in industrial processes, such as using lubricants to reduce friction or applying primers to enhance paint adhesion.