Kontaktikulma

Kontaktikulma is a Finnish term that translates to "contact angle" in English. It refers to the angle formed at the point where a liquid interface meets a solid surface. This angle is a measure of the wettability of a solid surface by a liquid. It is determined by the interplay of the interfacial tensions between the liquid and the solid, the liquid and the vapor, and the solid and the vapor.

The contact angle is a crucial parameter in many scientific and engineering applications. In surface science, it is used to characterize the surface properties of materials, such as their hydrophobicity or hydrophilicity. For example, a low contact angle (close to 0 degrees) indicates that the liquid spreads easily on the surface, suggesting good wettability. Conversely, a high contact angle (close to 180 degrees) indicates that the liquid beads up on the surface, meaning poor wettability.

Applications of contact angle measurements are diverse. In the textile industry, it helps in understanding how fabrics absorb moisture or repel liquids. In the field of coatings, it is used to assess the adhesion of paints, inks, and adhesives to various substrates. In the medical device industry, contact angle is important for designing implants and drug delivery systems that interact with biological fluids. It also plays a role in microfluidics, where the behavior of small volumes of liquid on surfaces is critical. The measurement of contact angle is typically performed using specialized equipment such as a goniometer.