Wettability is one of the most important properties of a solid surface, influenced by both its chemical composition and its morphological structure. An eloquent example of this phenomenon is the lotus leaf, which has numerous contact angles and low adhesion, allowing water to slip easily. In contrast, the rose petal, despite having high contact angles, shows high adhesion for water droplets.

When a solid surface is sufficiently rough, the liquid may not conform completely to it, due to the presence of a layer of air trapped beneath the liquid. This state is known as the Cassie state. Since air is hydrophobic, it reduces the interface area between the liquid and the solid surface, thus decreasing intermolecular interactions.

Nobilium Thermalpanel basalt thermal insulation panel, the heart of the dehumidifying coating Dwall, is made of rock fibers with micrometer diameters. Parallel fibers, called contact angles, differ from those in the orthogonal direction. The roughness of a surface alters the contact angle, affecting wettability.

The contact angle provides important information about the affinity between the solid, liquid and air. Roughness, by trapping air in the structure, creates the Cassie state, which is characterized by high contact angles and low adhesion of the liquid to the solid surface.

Although engineers and scholars in the past developed lime plaster solutions to counter capillary rise and deterioration of damp masonry, the situation has changed little over time. Even with the introduction of modern chemical additives such as aerating agents, hydrophobizing agents, thickeners, and anti-mold, deterioration of masonry structures remains a persistent problem.

The dehumidifying coating Dwall is a particularly attractive solution, especially in light of new policies aimed at improving the energy performance of historic buildings plagued by rising damp problems. Nobilium Thermalpanel insulation remains dry due to a lotus leaf-like wetting angle, promoting high moisture evaporation from masonry and significantly improving heat loss recovery.