MATERIALI CON BAGNABILITÀ CONTROLLATA. UN’ISPIRAZIONE DALLA NATURA

Abstract

The wettability of solid surfaces is the result of the balance between adhesive and cohesive forces. When adhesive forces at the solid/liquid interface prevail over the cohesive forces in the liquid, the drops will spread over the solid leading to a good wetting as in the case of water over an hydrophilic surface. When instead the adhesive forces are weak, the liquid will not wet the surface remaining in droplets, as water on a polymer. Natural materials exhibit tailored wetting behavior: for instance, certain leaves and insects present superhydrophobic properties. By mimicking what nature creates in an exemplary way, the wetting properties of systems can be tailored experimentally to obtain materials with great applicative impact. The possible applications of such phenomena are very numerous and span from biomaterials to antistain materials, from antifog surfaces to systems for the protection of cultural heritage.