Niiskumisvõime

Niiskumisvõime, often translated as wettability, refers to the ability of a liquid to maintain contact with a solid surface, resulting from intermolecular interactions when the two are brought together. It is a measure of how well a liquid spreads out on a solid. This property is crucial in various natural and industrial processes.

The extent of wettability is determined by the balance of forces between adhesion and cohesion. Adhesive forces are those of attraction between the liquid and the solid surface, while cohesive forces are those of attraction between the liquid molecules themselves. If adhesive forces are stronger than cohesive forces, the liquid will spread and wet the surface. Conversely, if cohesive forces are dominant, the liquid will tend to bead up and minimize contact.

Wettability is quantified by the contact angle, which is the angle where a liquid-solid interface meets the three-phase boundary. A low contact angle (less than 90 degrees) indicates good wettability, meaning the liquid spreads easily. A high contact angle (greater than 90 degrees) signifies poor wettability, where the liquid beads up.

Understanding niiskumisvõime is essential in fields such as painting, coating, printing, and lubrication, as it directly influences adhesion, surface tension effects, and the uniformity of liquid application. It also plays a role in biological systems, like the ability of water to permeate soil or the functioning of lung surfactant.