The nature of hydroxyl groups in aluminosilicate glasses: Quantifying Si-OH and Al-OH abundances along the SiO2-NaAlSiO4 join by 1H, 27Al-1H and 29Si-1H NMR spectroscopy

Wim J. Malfait, Xianyu Xue

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

The combined results of 27Al-1H and 1H-29Si-1H cross polarization NMR experiments for hydrous glasses (containing 0.5-2 wt% water) along the SiO2-NaAlSiO4 join confirm that the dissolution mechanism of water in aluminosilicate glasses is fundamentally the same as for Al-free systems, i.e. the dissolved water ruptures oxygen bridges and creates Si-OH and Al-OH groups, in addition to forming molecular water (H2Omol). The fraction of Al-OH increases non-linearly as the Al content increases with up to half of the OH groups as Al-OH for compositions close to NaAlSiO4. The relative abundances of the different species are controlled by the degree of Al-avoidance and the relative tendency of hydrolysis of the different types of oxygen bridges, Si-O-Si, Si-O-Al and Al-O-Al. A set of homogeneous reactions is derived to model the measured Al-OH/Si-OH speciation, and the obtained equilibrium constants are in agreement with literature data on the degree of Al-avoidance. With these equilibrium constants, the abundance of the different oxygen species, i.e. Si-O-Si, Si-O-Al, Al-O-Al, Si-OH, Al-OH and H2Omol, can be predicted for the entire range of water and Al contents.

Original languageEnglish
Pages (from-to)719-737
Number of pages19
JournalGeochimica et Cosmochimica Acta
Volume74
Issue number2
DOIs
Publication statusPublished - Jan 15 2010

Fingerprint

aluminosilicate
Hydroxyl Radical
Nuclear magnetic resonance spectroscopy
nuclear magnetic resonance
glass
spectroscopy
Glass
Water
Equilibrium constants
Oxygen
oxygen
water
rupture
hydrolysis
relative abundance
Hydrolysis
Dissolution
polarization
dissolution
Nuclear magnetic resonance

ASJC Scopus subject areas

  • Geochemistry and Petrology

Cite this

@article{792d830095344a6abb2e7a399cb2c51c,
title = "The nature of hydroxyl groups in aluminosilicate glasses: Quantifying Si-OH and Al-OH abundances along the SiO2-NaAlSiO4 join by 1H, 27Al-1H and 29Si-1H NMR spectroscopy",
abstract = "The combined results of 27Al-1H and 1H-29Si-1H cross polarization NMR experiments for hydrous glasses (containing 0.5-2 wt{\%} water) along the SiO2-NaAlSiO4 join confirm that the dissolution mechanism of water in aluminosilicate glasses is fundamentally the same as for Al-free systems, i.e. the dissolved water ruptures oxygen bridges and creates Si-OH and Al-OH groups, in addition to forming molecular water (H2Omol). The fraction of Al-OH increases non-linearly as the Al content increases with up to half of the OH groups as Al-OH for compositions close to NaAlSiO4. The relative abundances of the different species are controlled by the degree of Al-avoidance and the relative tendency of hydrolysis of the different types of oxygen bridges, Si-O-Si, Si-O-Al and Al-O-Al. A set of homogeneous reactions is derived to model the measured Al-OH/Si-OH speciation, and the obtained equilibrium constants are in agreement with literature data on the degree of Al-avoidance. With these equilibrium constants, the abundance of the different oxygen species, i.e. Si-O-Si, Si-O-Al, Al-O-Al, Si-OH, Al-OH and H2Omol, can be predicted for the entire range of water and Al contents.",
author = "Malfait, {Wim J.} and Xianyu Xue",
year = "2010",
month = "1",
day = "15",
doi = "10.1016/j.gca.2009.10.036",
language = "English",
volume = "74",
pages = "719--737",
journal = "Geochmica et Cosmochimica Acta",
issn = "0016-7037",
publisher = "Elsevier Limited",
number = "2",

}

TY - JOUR

T1 - The nature of hydroxyl groups in aluminosilicate glasses

T2 - Quantifying Si-OH and Al-OH abundances along the SiO2-NaAlSiO4 join by 1H, 27Al-1H and 29Si-1H NMR spectroscopy

AU - Malfait, Wim J.

AU - Xue, Xianyu

PY - 2010/1/15

Y1 - 2010/1/15

N2 - The combined results of 27Al-1H and 1H-29Si-1H cross polarization NMR experiments for hydrous glasses (containing 0.5-2 wt% water) along the SiO2-NaAlSiO4 join confirm that the dissolution mechanism of water in aluminosilicate glasses is fundamentally the same as for Al-free systems, i.e. the dissolved water ruptures oxygen bridges and creates Si-OH and Al-OH groups, in addition to forming molecular water (H2Omol). The fraction of Al-OH increases non-linearly as the Al content increases with up to half of the OH groups as Al-OH for compositions close to NaAlSiO4. The relative abundances of the different species are controlled by the degree of Al-avoidance and the relative tendency of hydrolysis of the different types of oxygen bridges, Si-O-Si, Si-O-Al and Al-O-Al. A set of homogeneous reactions is derived to model the measured Al-OH/Si-OH speciation, and the obtained equilibrium constants are in agreement with literature data on the degree of Al-avoidance. With these equilibrium constants, the abundance of the different oxygen species, i.e. Si-O-Si, Si-O-Al, Al-O-Al, Si-OH, Al-OH and H2Omol, can be predicted for the entire range of water and Al contents.

AB - The combined results of 27Al-1H and 1H-29Si-1H cross polarization NMR experiments for hydrous glasses (containing 0.5-2 wt% water) along the SiO2-NaAlSiO4 join confirm that the dissolution mechanism of water in aluminosilicate glasses is fundamentally the same as for Al-free systems, i.e. the dissolved water ruptures oxygen bridges and creates Si-OH and Al-OH groups, in addition to forming molecular water (H2Omol). The fraction of Al-OH increases non-linearly as the Al content increases with up to half of the OH groups as Al-OH for compositions close to NaAlSiO4. The relative abundances of the different species are controlled by the degree of Al-avoidance and the relative tendency of hydrolysis of the different types of oxygen bridges, Si-O-Si, Si-O-Al and Al-O-Al. A set of homogeneous reactions is derived to model the measured Al-OH/Si-OH speciation, and the obtained equilibrium constants are in agreement with literature data on the degree of Al-avoidance. With these equilibrium constants, the abundance of the different oxygen species, i.e. Si-O-Si, Si-O-Al, Al-O-Al, Si-OH, Al-OH and H2Omol, can be predicted for the entire range of water and Al contents.

UR - http://www.scopus.com/inward/record.url?scp=70649090284&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70649090284&partnerID=8YFLogxK

U2 - 10.1016/j.gca.2009.10.036

DO - 10.1016/j.gca.2009.10.036

M3 - Article

AN - SCOPUS:70649090284

VL - 74

SP - 719

EP - 737

JO - Geochmica et Cosmochimica Acta

JF - Geochmica et Cosmochimica Acta

SN - 0016-7037

IS - 2

ER -