HYDROLYSIS CONDENSATION REACTIONS AT THE SOL-GEL/AIR INTERFACE - PURETITANIA ALKOXIDE EXPOSED TO AIR-WATER MOLECULES/

Sol-gel alkoxides an very often sensitive to the surrounding air humid ity, especially when the chemical evolution of the sol is operating at time scales comparable to the water-molecule diffusion from the surro unding air inside the medium and their interaction with the alkoxide m olecules. The present study reports the in situ observation and interp retation of hydrolysis/condensation reactions occurring within the sur face layers of pure titanium(IV) butoxide exposed to air, which illust rates the interest of the methodology for studies of near-surface chem istry in sol gel evolutions and thin films.