Conversion of a solid surface from super-hydrophobic to super-hydrophilic by photocatalytic remote oxidation and photocatalytic lithography

A super-hydrophobic surface, of which contact angle was 1518, was obtained by modifying a SiO2 microparticle film-coated glass plate with octadecyltriethoxysilane (ODS). The super-hydrophobic surface was converted to super-hydrophilic by remote oxidation using a TiO2 photocatalyst for 40 min, due to oxidative decomposition of the ODS monolayer. The increase in the wettability of the super-hydrophobic surface with water was faster than that of a normal hydrophobic surface. Patterning of the super-hydrophobic surface was also possible by means of photocatalytic lithography based on the remote oxidation using a photomask. It was possible to entrap water in the oxidized regions