IR SPECTROMETRY STUDY OF THE GELS IN THE SIO2-P2O5 SYSTEM

The hydrolysis-condensation in binary P-alkoxide - Si-alkoxide systems was studied. As Phosphorous precursors the following type of reagents were used: H3PO4, (CH3O)(3)PO, (CH3O)(2)POH, (C2H5O)(3)P, (C6H5O)(3)P . The molecular species formed during the sol-gel transition in the bi nary considered system have been determined by gas chromatography coup led with mass spectrometry (GC-MS) and the structures of the obtained gels have been studied by IR spectrometry. The spectra of as-prepared gels have been numerically analyzed in order to emphasize the modifica tion that occurs in the peaks positions and shape. The results obtaine d by IR spectrometry were confirmed by X-ray diffraction (XRD). The ge lling tendency and the structure of the obtained gels are strongly inf luenced by the P-precursor used in the sol-gel method of preparation.