Structure vs. composition: A solid-state 1H and 29Si NMR study of quenched glasses along the Na2O-SiO2-H2O join

Cody, George D.; Mysen, Bjørn O.; Lee, Sung Keun

doi:10.1016/j.gca.2004.11.012

Cited by 75 publications

(72 citation statements)

References 43 publications

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“…A similar broad peak is observed in the spectrum of NS4 glass with 5.5 wt% H 2 O dissolved, but without C-bearing components in solution. Similar spectral features are common in 1 H MAS NMR spectra of hydrous glasses (e.g., Kohn et al, 1989;Cody et al, 2005). To the best of our knowledge, 1 H MAS NMR spectra of silicate glasses from melts equili- Fig.…”

Section: Hydrogen-1 Mas Nmr Spectrasupporting

confidence: 62%

“…The peaks near 1.3, 1.5, 2.4, 4.3, and 5.4 ppm in the 1 H MAS NMR spectrum of quenched NS4 + CH 4 melt are assigned to protons in (C..H)-containing complexes (Pretsch et al, 2000), whereas the broad peak centered near 15 ppm and the broad intensity beneath the sharper peaks in the 7-0 ppm range are assigned to proton resonances in OH groups (e.g., Kohn et al, 1989;Cody et al, 2005). These features are further demonstrated with the 1 H MAS NMR spectrum of hydrous ($5.5 wt% H 2 O) NS4 melt composition where only broad peaks near 7 and 15 ppm can be seen (Fig.…”

Section: Nmr Spectroscopymentioning

confidence: 99%

“…For example, local environmental variations have been reported to cause several ppm shifts in the 1 H resonance of H 2 in chlatrates as compared with the shift of isolated H 2 molecules (Florusse et al, 2004;Strobel et al, 2006). Even greater frequency changes can be caused by hydrogen bonding (e.g., Cody et al, 2005) NMR spectrum are not, therefore, certain and require substantiation with examination by other spectroscopic methods. Raman spectroscopy is used here for this purpose.…”

Section: Nmr Spectroscopymentioning

confidence: 99%

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Solution behavior of reduced COH volatiles in silicate melts at high pressure and temperature

Mysen

Fogel

Morrill

et al. 2009

Geochimica et Cosmochimica Acta

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The solubility and solution mechanisms of reduced CAOAH volatiles in Na 2 OASiO 2 melts in equilibrium with a (H 2 + CH 4 ) fluid at the hydrogen fugacity defined by the iron-wü stite + H 2 O buffer [f H2 (IW)] have been determined as a function of pressure (1-2.5 GPa) and silicate melt polymerization (NBO/Si: nonbridging oxygen per silicon) at 1400°C. The solubility, calculated as CH 4 , increases from $0.2 wt% to $0.5 wt% in the melt NBO/Si-range $0.4 to $1.0. The solubility is not significantly pressure-dependent, probably because f H2 (IW) in the 1-2.5 GPa range does not vary greatly with pressure. Carbon isotope fractionation between methane-saturated melts and (H 2 + CH 4 ) fluid varied by $14& in the NBO/Si-range of these melts. The (C..H) and (O..H) speciation in the quenched melts was determined with Raman and 1 H MAS NMR spectroscopy. The dominant (C..H)-bearing complexes are molecular methane, CH 4 , and a complex or functional group that includes entities with C"CAH bonding. Minor abundance of complexes that include SiAOACH 3 bonding is tentatively identified in some melts. There is no spectroscopic evidence for SiAC or SiACH 3 . Raman spectra indicate silicate melt depolymerization (increasing NBO/Si). The [CH 4 /C"CAH] melt abundance ratio is positively correlated with NBO/Si, which is interpreted to suggest that the (C"CAH)-containing structural entity is bonded to the silicate melt network structure via its nonbridging oxygen. The $14& carbon isotope fractionation change between fluid and melt is because of the speciation changes of carbon in the melt.

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Section: Hydrogen-1 Mas Nmr Spectrasupporting

confidence: 62%

Section: Nmr Spectroscopymentioning

confidence: 99%

Section: Nmr Spectroscopymentioning

confidence: 99%

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Solution behavior of reduced COH volatiles in silicate melts at high pressure and temperature

Mysen

Fogel

Morrill

et al. 2009

Geochimica et Cosmochimica Acta

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“…The 1 H NMR shift in silicate glasses has been extensively studied (e.g. Eckert et al, 1988;Kummerlen et al, 1992;Riemer et al, 2000;Schmidt et al, 2000;Cody et al, 2005;Xue and Kanzaki, 2008). The 1 H ppm shift centered at 5.0 ppm can be attributed to hydrogen atoms with different configurations: SiOH, water molecules in the vicinity of SiO 4 tetrahedra.…”

Section: Free Carbonate Clusters As Precursors To Liquid Immiscibilitmentioning

confidence: 99%

Carbon dioxide in silica-undersaturated melt. Part I: The effect of mixed alkalis (K and Na) on CO2 solubility and speciation

Morizet

Paris

Gaillard

et al. 2014

Geochimica et Cosmochimica Acta

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“…(1) is documented by numerous nuclear magnetic resonance (NMR) and infrared (IR) spectroscopic studies (e.g., Scholtze 1960;Moulson and Roberts 1961;Bartholomew et al 1980;Stolper 1982;Kohn et al 1989a, b;Zotov and Keppler 1998), which also indicated that OH groups seem bonded predominantly to Si (see also Farnan et al 1987;Cody et al 2005;Mysen and Cody 2005). Therefore, in this simple model, H 2 O mol reacts predominantly with bridging oxygens (BO), breaking T-O-T bonds (with T = Si, Al), so that Eq.…”

Section: Introductionmentioning

confidence: 95%

Water and magmas: insights about the water solution mechanisms in alkali silicate melts from infrared, Raman, and 29Si solid-state NMR spectroscopies

Losq

Mysen

Cody

2015

Prog. in Earth and Planet. Sci.

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Degassing of water during the ascent of hydrous magma in a volcanic edifice produces dramatic changes in the magma density and viscosity. This can profoundly affect the dynamics of volcanic eruptions. The water exsolution history, in turn, is driven by the water solubility and solution mechanisms in the silicate melt. Previous studies pointed to dissolved water in silicate glasses and melts existing as molecules (H 2 O mol species) and hydroxyl groups, OH. These latter OH groups commonly are considered bonded to Si 4+ but may form other bonds, such as with alkali or alkaline-earth cations, for instance. Those forms of bonding influence the structure of hydrous melts in different ways and, therefore, their properties. As a result, exsolution of water from magmas may have different eruptive consequences depending on the initial bonding mechanisms of the dissolved water. However, despite their importance, the solution mechanisms of water in silicate melts are not clear. In particular, how chemical composition of melts affects water solubility and solution mechanism is not well understood. In the present experimental study, components of such information are reported via determination of how water interacts with the cationic network of alkali (Li, Na, and K) silicate quenched melts. Results from 29 Si single-pulse magic-angle spinning nuclear magnetic resonance ( 29 Si SP MAS NMR), infrared, and Raman spectroscopies show that decreasing the ionic radius of alkali metal cation in silicate melts results in decreasing fraction of water dissolved as OH groups. The nature of OH bonding also changes as the alkali ionic radius changes. Therefore, as the speciation and bonding of water controls the degree of polymerization of melts, water will have different effects on the transport properties of silicate melts depending on their chemical composition. This conclusion, in turn, may affect volcanic phenomena related to the viscous relaxation of hydrous magmas, such as for instance the fragmentation process that occurs during explosive eruptions.

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Structure vs. composition: A solid-state 1H and 29Si NMR study of quenched glasses along the Na2O-SiO2-H2O join

Cited by 75 publications

References 43 publications

Solution behavior of reduced COH volatiles in silicate melts at high pressure and temperature

Solution behavior of reduced COH volatiles in silicate melts at high pressure and temperature

Carbon dioxide in silica-undersaturated melt. Part I: The effect of mixed alkalis (K and Na) on CO2 solubility and speciation

Water and magmas: insights about the water solution mechanisms in alkali silicate melts from infrared, Raman, and 29Si solid-state NMR spectroscopies

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