Water permeability of quarry stone superficially modified by plasma polymerization of hexamethyldisiloxane at atmospheric pressure

The surface of quarry stone was modified with a thin film of plasma-polymerized hexamethyldisiloxane (PPHMDSO) deposited at atmospheric pressure. The surface of the treated stone turned hydrophobic as shown by water contact angle measurements. FTIR characterization showed CH3 and Si-CH3 bands characteristic of HDMSO functional groups. Finally, the water absorption of untreated and PPHMDSO-modified stones was studied. In both cases, the water absorption profile was consistent with Fickian diffusion but the treated stone absorbed 8 times less water than the untreated stone.