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dc.contributor.author Winter, Rudolf
dc.contributor.author Smith, I. H.
dc.contributor.author Jones, Aled R.
dc.contributor.author Greaves, G. N.
dc.date.accessioned 2008-12-08T10:47:36Z
dc.date.available 2008-12-08T10:47:36Z
dc.date.issued 2005
dc.identifier.citation Winter , R , Smith , I H , Jones , A R & Greaves , G N 2005 , ' Na-23, Si-29, and C-13 MAS NMR investigation of glass-forming reactions between Na2CO3 and SiO2 ' Journal of Physical Chemistry B , vol 109 , no. 49 , pp. 23154-23161 . , 10.1021/jp053953y en
dc.identifier.issn 1520-6106
dc.identifier.other PURE: 89079
dc.identifier.other dspace: 2160/1434
dc.identifier.uri http://hdl.handle.net/2160/1434
dc.identifier.uri http://pubs.acs.org/cgi-bin/abstract.cgi/jpcbfk/2005/109/i49/abs/jp053953y.html en
dc.description Winter, Rudolf; Jones, A.R.; Greaves, G.N.; Smith, I.H., (2005) 'Na-23, Si-29, and C-13 MAS NMR investigation of glass-forming reactions between Na2CO3 and SiO2', Journal of Physical Chemistry B 109(49) pp.23154-23161 RAE2008 en
dc.description.abstract The glass-forming reactions between sodium carbonate (Na2CO3) and silica (SiO2) have been investigated by 23Na, 29Si, and 13C magic-angle spinning (MAS) NMR spectroscopy. The multinuclear MAS NMR approach identifies and quantifies reaction products and intermediates, both glassy and crystalline. A series of powdered batches of initial composition Na2CO3·xSiO2 (x = 1, 2) corresponding to a sodium metasilicate (Na2SiO3) and sodium disilicate (Na2Si2O5) stoichiometry were investigated after periods of isothermal and nonisothermal heat treatments at different temperatures. Analysis of the 23Na quadrupolar coupling parameters has identified the early reaction product in all cases as crystalline Na2SiO3. In the nonisothermal experiment, this reaction is preceded by an early silica-rich melt phase formed around 850 °C. The early reactions are controlled by solid-state Na+ diffusion across the reaction zone in the grain interface layer. Crystalline Na2SiO3 precipitates in the interface layer, increasing its thickness between the Na2CO3 and the SiO2 grains and slowing down the rate of Na+ migration. This creates a secondary phase, which is temperature dependent. At low temperatures, where Na+ migration is impaired, the production of Na2SiO3 ceases and silica-richer phases are precipitated. In the case of the sodium disilicate batch, where excess SiO2 is present, a secondary reaction of Na2SiO3 with SiO2 forming a glassy phase is observed. A transient carbon-bearing phase has been identified by 13C NMR as a NaCO3- complex loosely bound to bridging oxygens in the silicate network at the SiO2 grain surface. en
dc.format.extent 8 en
dc.language.iso eng
dc.relation.ispartof Journal of Physical Chemistry B en
dc.title Na-23, Si-29, and C-13 MAS NMR investigation of glass-forming reactions between Na2CO3 and SiO2 en
dc.type Text en
dc.type.publicationtype Article (Journal) en
dc.identifier.doi http://dx.doi.org/10.1021/jp053953y
dc.contributor.institution Institute of Mathematics & Physics (ADT) en
dc.contributor.institution Mathematics and Physics en
dc.description.status Peer reviewed en


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