Großhydrophobe

Großhydrophobe is a German term that translates to "very hydrophobic" or "highly water-repellent" in English. It describes a surface or material that exhibits an extreme aversion to water. This property is typically quantified by the contact angle a water droplet makes with the surface. Surfaces with a contact angle greater than 90 degrees are considered hydrophobic, and those with a contact angle significantly exceeding this, often above 150 degrees, are classified as großhydrophobe.

The großhydrophobe effect is achieved through specific surface topography and chemistry. Nanoscale or microscale structures can trap air, reducing the actual contact area between the water and the solid surface, thus increasing the contact angle. Combined with a low surface energy material, such as certain polymers or treated metals, this creates a surface that repels water droplets, causing them to bead up and roll off easily. Lotus leaves are a classic biological example of a naturally großhydrophobe surface, a phenomenon known as the lotus effect.

Materials exhibiting großhydrophobe properties have numerous applications. These include self-cleaning surfaces for buildings and vehicles, anti-icing coatings for aircraft, stain-resistant textiles, and microfluidic devices where precise control of liquid movement is crucial. The development and application of großhydrophobe materials continue to be an active area of research in materials science and engineering, aiming to enhance durability, reduce environmental impact, and create novel functional surfaces.