New insights into oxygen environments generated during phosphate glass alteration: a combined 17O MAS and MQMAS NMR and first principles calculations study.
In the present study, we used a combination of (17)O NMR methods at a high magnetic field with first-principles calculations in order to characterize the oxygen sites in a series of hydroxylated sodium phosphate compounds, namely the hydrogen pyrophosphate Na(2)H(2)P(2)O(7) and the hydrogen orthophosphates NaH(2)PO(4), NaH(2)PO(4) x H(2)O and NaH(2)PO(4) x 2 H(2)O. The chemical shifts and quadrupolar parameters of these compounds were interpreted in terms of local and semi-local environment, i.e., the chemical composition of the immediate surroundings and the nature of the bonds, e.g. hydrogen bonding. The magnitude of the quadrupolar interaction and its asymmetry were revealed to be a precise indicator of the local structure in sodium hydrogen phosphates. Our (17)O NMR experimental and computing approach allowed for identification and quantification of the different crystalline phases involved in the weathering mechanism of a sodium phosphate glass, even in small amount.
Forler
Nina
N
UCCS-Unité de Catalyse et Chimie du Solide, UMR CNRS 8181, Ecole Nationale Supérieure de Chimie de Lille, Université des Sciences et Technologies de Lille, BP 108, 59652 Villeneuve d'Ascq Cedex, France.
Vasconcelos
Filipe
F
Cristol
Sylvain
S
Paul
Jean-François
JF
Montagne
Lionel
L
Charpentier
Thibault
T
Mauri
Francesco
F
Delevoye
Laurent
L
D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D010100:Oxygen / Q000737:chemistry*; D010103:Oxygen Isotopes / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry*
D010103:Oxygen Isotopes; D010710:Phosphates; D010100:Oxygen; C018279:sodium phosphate