Sol-gel synthesis of SiO2P2O5 glasses

摘要: The synthesis of P2O5SiO2 glasses from solutions has been studied through gelation kinetics, Raman and nuclear magnetic resonance (NMR) spectroscopies. Different preparation methods are compared. effect the phosphorus precursor investigated. Phosphoric acid esters not hydrolyzed they do yield condensation with silica. Reaction anhydrous H3PO4 SiOR groups leads to formation SiOP bonds which easily hydrolyzed. Only a few remain after addition water gelation. Therefore, PSi homogeneity is difficult achieve following drying heat-treatment procedures. This absence observed by solid-state magic angle spinning (MAS)-NMR X-ray diffraction studies performed on gel samples heated at 300, 500 800°C in case xerogels 500, 950 1140°C for aerogels.