29Si NMR and SAXS investigation of the hybrid organic-inorganic glasses obtained by consolidation of the melting gels.

摘要: This study is focused on structural characterization of hybrid glasses obtained by consolidation melting gels. The gels were prepared in molar ratios methyltriethoxysilane (MTES) and dimethyldiethoxysilane (DMDES) 75%MTES-25%DMDES 65%MTES-35%DMDES. Following consolidation, the characterized using Raman, 29Si 13C Nuclear Magnetic Resonance (NMR) spectroscopies, synchrotron Small Angle X-Ray Scattering (SAXS) scanning electron microscopy (SEM). Raman spectroscopy revealed presence Si–C bonds 8-membered ring structures Si–O–Si network. Qualitative NMR identified main molecular species, while quantitative data showed that ratio trimers (T) to dimers (D) varied between 4.6 3.8. Two-dimensional used identify two distinct types T3 environments. SAXS are homogeneous across nm micrometer length scales. scattering cross section was one thousand times lower than what expected when phase separation occurs. SEM images show a uniform surface without defects, agreement with results, which further supports nonporous.