vízelhárító

A vízelhárító, often translated as water repellent or water-repelling agent, is a substance or treatment applied to a material to prevent or reduce the absorption of water. The primary function of a vízelhárító is to create a barrier on the surface of the material, causing liquids to bead up and roll off rather than soak in. This property is achieved through various chemical and physical mechanisms, often involving compounds that have low surface energy.

These treatments are commonly used in textiles, such as clothing, footwear, and outdoor gear, to enhance their resistance to rain and moisture, thereby keeping the wearer dry and comfortable. In construction, vízelhárító treatments can be applied to porous materials like concrete, stone, and brick to protect them from water damage, frost heave, and the growth of mold and mildew. They can also be found in coatings for glass and other surfaces to improve visibility in wet conditions by preventing water from forming a continuous film.

The effectiveness and durability of a vízelhárító can vary depending on the type of agent used and the material it is applied to. Some treatments are temporary and may require reapplication after washing or exposure to the elements, while others are designed to be long-lasting. The mechanism often involves altering the material's surface tension, making it less receptive to water molecules.