TY - JOUR
T1 - Al coordination and water speciation in hydrous aluminosilicate glasses
T2 - Direct evidence from high-resolution heteronuclear 1H-27Al correlation NMR
AU - Xue, Xianyu
AU - Kanzaki, Masami
N1 - Funding Information:
We thank an anonymous reviewer and R.E. Botto, for helpful comments/suggestions. This study was supported by Grant-in-Aid for Scientific Research to X.X. (No. 17340164) and the COE-21 Program, both funded by the Ministry of Education, Culture, Sports, Science and Technology of Japan.
PY - 2007/2
Y1 - 2007/2
N2 - In order to shed light on the dissolution mechanisms of water in depolymerized aluminosilicate melts/glasses, a comprehensive one- (1D) and two-dimensional (2D) NMR study has been carried out on hydrous Ca- and Mg-aluminosilicate glasses of a haplobasaltic composition. The applied techniques include 1D 1H MAS NMR and 27Al→1H cross-polarization (CP) MAS NMR, and 2D 1H NOESY and double-quantum (DQ) MAS NMR, 27Al triple-quantum (3Q) MAS NMR and 27Al→1H heteronuclear correlation (HETCOR) and 3QMAS/HETCOR NMR. Ab initio calculations were also performed to place additional constraints on the 1H NMR characteristics of AlOH and Si(OH)Al groups. This study has revealed, for the first time, the presence of free OH (i.e. (Ca, Mg)OH), SiOH and AlOH species, in addition to molecular H2O, in hydrous glasses of a depolymerized aluminosilicate composition. The AlOH groups are mostly associated with four-coordinate Al, but some are associated with five- and six-coordinate Al.
AB - In order to shed light on the dissolution mechanisms of water in depolymerized aluminosilicate melts/glasses, a comprehensive one- (1D) and two-dimensional (2D) NMR study has been carried out on hydrous Ca- and Mg-aluminosilicate glasses of a haplobasaltic composition. The applied techniques include 1D 1H MAS NMR and 27Al→1H cross-polarization (CP) MAS NMR, and 2D 1H NOESY and double-quantum (DQ) MAS NMR, 27Al triple-quantum (3Q) MAS NMR and 27Al→1H heteronuclear correlation (HETCOR) and 3QMAS/HETCOR NMR. Ab initio calculations were also performed to place additional constraints on the 1H NMR characteristics of AlOH and Si(OH)Al groups. This study has revealed, for the first time, the presence of free OH (i.e. (Ca, Mg)OH), SiOH and AlOH species, in addition to molecular H2O, in hydrous glasses of a depolymerized aluminosilicate composition. The AlOH groups are mostly associated with four-coordinate Al, but some are associated with five- and six-coordinate Al.
KW - 3QMAS/HETCOR
KW - Al
KW - Al coordination
KW - Aluminosilicate glass
KW - CPMAS
KW - H
KW - Structure
KW - Water speciation
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U2 - 10.1016/j.ssnmr.2006.11.001
DO - 10.1016/j.ssnmr.2006.11.001
M3 - Article
C2 - 17196798
AN - SCOPUS:33847661001
SN - 0926-2040
VL - 31
SP - 10
EP - 27
JO - Solid State Nuclear Magnetic Resonance
JF - Solid State Nuclear Magnetic Resonance
IS - 1
ER -