Thermo-oxidative investigation on SiO2 and SiO2–ZrO2 composites prepared by sol–gel route.

SiO₂, ZrO₂ and SiO₂–ZrO₂ composites at different percentages of zirconia were synthesized by the sol–gel method and spectroscopically characterized by Fourier transform infrared (FTIR) spectroscopy. Different series of composites were prepared and analyzed, as it is and with a post-preparation conditioning at 600 and 1000 °C, respectively. The calcination were carried out to verify the changing in composite structure and whether these treatments will affect the subsequently characterization. In fact, silica, zirconia and their composites were than subjected to oxidative degradation up to 800 °C by the means of thermogravimetric analysis (TGA). Residues, obtained at 800 °C by the thermogravimetric (TG) scans, were analyzed by FTIR to evaluate the differences with the spectra of the composites obtained before TGA. TG curves were discussed to describe the thermal behavior of the prepared composites and to highlight the influence of zirconia amount on the composites degradation behavior. [ABSTRACT FROM AUTHOR]