Solid state 29Si, 31P and 1H MAS-NMR were used to investigate structural aspects of gel-derived glasses of molar compn. 10P2O5-90SiO2 (10P) and 30P2O5-70SiO2 (30P). 31P MAS-NMR spectra of the 10P and 30P gels dried at 100°C show resonances characteristic of orthophosphoric and pyrophosphoric acid. No evidence for crosslinking with silicate matrix was found by 29Si NMR at this temp. while 1H MAS-NMR expts. suggest that the chem. environment of OH groups is very similar in these samples. In spite of this initial similarity further heating causes markedly different structural rearrangements of the 10P and 30P gel matrix.
SOLID STATE NMR STUDY OF PHOSPHOSILICATE GELS / Clayden, N. J.; Aronne, Antonio; Esposito, S.; Pernice, Pasquale. - In: JOURNAL OF NON-CRYSTALLINE SOLIDS. - ISSN 0022-3093. - STAMPA. - 345-346:(2004), pp. 601-604.
SOLID STATE NMR STUDY OF PHOSPHOSILICATE GELS
ARONNE, ANTONIO;PERNICE, PASQUALE
2004
Abstract
Solid state 29Si, 31P and 1H MAS-NMR were used to investigate structural aspects of gel-derived glasses of molar compn. 10P2O5-90SiO2 (10P) and 30P2O5-70SiO2 (30P). 31P MAS-NMR spectra of the 10P and 30P gels dried at 100°C show resonances characteristic of orthophosphoric and pyrophosphoric acid. No evidence for crosslinking with silicate matrix was found by 29Si NMR at this temp. while 1H MAS-NMR expts. suggest that the chem. environment of OH groups is very similar in these samples. In spite of this initial similarity further heating causes markedly different structural rearrangements of the 10P and 30P gel matrix.File | Dimensione | Formato | |
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