Water repellent ORMOSIL films for the protection of stone and other materials

Organically modified silica (ORMOSIL) gels were produced through a sol-gel method and used to coat different materials, including glass, silicon, iron, paper, melinex and several stones, so as to examine the potential applications ranging from coatings of biomedical devices to cultural monuments. Superhydrophobicity and water repellence were induced on the surfaces of all the treated materials, as high static (>165°) and low tilt (<4°) contact angles were achieved. The treated surfaces were studied using scanning electron microscopy, which revealed the formation of a micro/nano-structured topography. It was shown that the wettability of the ORMOSIL films was not affected by (i) the underlying substrate or (ii) the pH of the water drop.