Kontaktvinkelsmåling

Kontaktvinkelsmåling is a technique used to characterize the wettability of a solid surface by a liquid. It involves measuring the angle formed at the three-phase contact line where a liquid droplet meets a solid surface. This angle, known as the contact angle, provides quantitative information about the interfacial tensions between the solid, liquid, and vapor phases. A low contact angle, typically less than 90 degrees, indicates that the liquid wets the solid surface well (hydrophilic if the liquid is water), while a high contact angle, greater than 90 degrees, signifies poor wetting (hydrophobic if the liquid is water).

The measurement is typically performed using a goniometer, which is an instrument equipped with a camera and optics to capture an image of the droplet on the surface. Specialized software then analyzes the image to determine the contact angle. Factors that can influence contact angle measurements include the surface roughness of the solid, the purity of the liquid and solid, and the ambient temperature and humidity. It is important to perform measurements under controlled conditions to ensure reproducibility and accuracy.

Kontaktvinkelsmåling has a wide range of applications across various scientific and industrial fields. In materials science, it is used to assess surface treatments, coatings, and the adhesion properties of materials. In biology and medicine, it helps understand cell adhesion, protein adsorption, and the biocompatibility of medical implants. The technique is also employed in the development of textiles, paints, and in the study of microfluidics and nanotechnology. By understanding how liquids interact with surfaces, researchers and engineers can optimize processes and design new materials with desired properties.