veehülgavust

Veehülgavust, also known as water repellency or hydrophobicity, refers to the physical property of a surface or material to resist wetting by water. A surface exhibiting veehülgavust will cause water droplets to bead up and roll off rather than spreading out and soaking in. This phenomenon is primarily a result of low surface energy. Materials with high surface tension, like water, tend to minimize their contact with surfaces that have even lower surface energy.

The degree of veehülgavust can be quantified by measuring the contact angle of a water droplet on the surface. A higher contact angle indicates greater veehülgavust, with contact angles above 90 degrees generally considered hydrophobic. Superhydrophobic surfaces can achieve contact angles exceeding 150 degrees. This extreme repellency is often achieved through a combination of surface chemistry and micro/nanoscale roughness, which traps air pockets beneath the water droplet.

Veehülgavust has numerous practical applications. It is utilized in textiles to create waterproof and stain-resistant fabrics, in construction materials to prevent water damage, and in coatings for electronics and optics to protect against moisture. In nature, veehülgavust is observed in the feathers of aquatic birds and the leaves of certain plants, such as the lotus leaf, which inspires the study of biomimetic superhydrophobic materials. The development of materials with controlled veehülgavust continues to be an active area of research.