SPECTROSCOPIC STUDY OF SIO2-TIO2 SOLS PREPARED USING STABILIZING AGENTS

Two chemical routes were employed to prepare Si-Ti polymers, using ace tylacetone (acacH) and acetic acid (HOAc) as modifying agents. The hom ogeneous and transparent sols were studied at different aging times. T he characterization techniques were Si-29 NMR, FTIR, UV-Vis and TGA. W hen HOAc was used, the oligomeric species in the first stages of polym erization were assigned by Si-29 NMR. The Ti-Q-Si bond vibration was d etected by FTIR in the 950-960 cm(-1) region. W-Vis spectroscopy showe d bands of acac bonded to Ti at 300 nm and 365 nm, and OAc- bonded to Ti was found at 320 nm. The TGA study allowed the establishment of the xerogel formulas.