Titania Nanofilms from Titanium Complex-Containing Polymer Langmuir-Blodgett Films

This paper proposes a method of fabricating low-dimensional TiO₂ nanofilms at room temperature under ambient pressure conditions. The titanium-containing polymer complex Ti-p(DDA/acac) was synthesized by reacting an amphiphilic copolymer (p(DDA/acac)) with a titanium complex. Its ultrathin films were prepared using the Langmuir-Blodgett (LB) technique. The monolayer was found to be free from hydrolysis and cross-linking side reactions, even at the air-water interface. The transferred LB films (nanosheets) were oxidized by ultraviolet irradiation at room temperature. The photo-oxidized material has an amorphous and porous structure with subnanometer-scale controllability (0.18 nm per layer). Photocatalytic performance was demonstrated by converting multilayered LB films of Ti-(DDA/acac) and the silicon-containing polymer p(DDA/SQ) into ultrathin hetero-multilayers of TiO₂ and SiO₂ under UV-O₃ treatment. The scalability affords a uniform photopattern formation of photo-oxidized TiO₂ films over several hundreds of micrometers.