Self-cleaning fiber cement facade cladding
INTELLIGENT SURFACE ZECCA PREFABBRICATI

In cooperation with the “Politecnico di Milano” Technical University, Piz srl has developed PIZ I.S., a cladding system obtained using titanium dioxide to alter the material’s surface characteristics, generating photocatalysis
and superhydrophilicity.

Thanks to its special dirt-resistant characteristics, PIZ I.S. enables to contain cleaning and maintenance costs, exploiting the chemical reaction following light absorption by a catalyst, also known as superhydrophilicity. This
phenomenon enables the water to spread evenly on the surface without generating drops. Thus, PIZ I.S. cladded walls are permanently covered by an invisible film generated by dampness in the air, which prevents the dirt from adhering to the wall. Any dirt may easily be removed with water.

A photocatalyst is a substance which uses sunlight to improve a chemical reaction without undergoing changes. During photosynthesis, for example, chlorophyll is a photocatalyst. When a photocatalyst absorbs natural or artificial UV rays, it produces couples of electrons and holes in the valence band. These holes have a strong oxidizing power, whereas electrons have a strong reducing power. When these couples of holes and electrons react with the dampness on the surface, the oxidizing power leads to the production of hydrogen radicals, which in turn react with pollutants and bacteria in the atmosphere. These are then decomposed into non-polluting substances which are easily washed away by the rain. Intelligent surface Reduction of air pollution and anti-bacterial properties.