Abstract
Detailed investigation of the Raman spectra of titanium tetraisopropoxide and the mixtures with diethanolamine have revealed the unique function of diethanolamine as an additive for controlling the sol-gel reaction. Diethanolamine makes a stable compounds with the alkoxide and prevents the alkoxide from a rapid hydrolysis/condensation reaction. The spectral peaks around 610cm-1 and 560cm-1 of the alkoxide and the related compounds correspond to the bridging Ti-O-Ti vibration of oligomeric species and Ti-O vibration of monomeric alkoxide, respectively. The intensity changes of the peaks shows the chemical and structural changes of the alkoxide in the course of gel formation. The alcoholysis reactions of the alkoxide with diethanolamine and ethanol were quantitatively studied by determining the amount of isopropanol liberated by the reaction.
