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(29)Si{(27)Al}, (27)Al{(29)Si} and (27)Al{(1)H} double-resonance NMR spectroscopy study of cementitious sodium aluminosilicate gels (geopolymers) and gel–zeolite composites

The influence of starting materials and synthesis route on the properties and the structure of cementitious sodium aluminosilicate gels is not fully understood, partly due their amorphous nature and the fact that they often contain residual reactants, which can make the results of single-pulse NMR s...

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Autores principales: Greiser, Sebastian, Gluth, Gregor J. G., Sturm, Patrick, Jäger, Christian
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9091287/
https://www.ncbi.nlm.nih.gov/pubmed/35558254
http://dx.doi.org/10.1039/c8ra09246j
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author Greiser, Sebastian
Gluth, Gregor J. G.
Sturm, Patrick
Jäger, Christian
author_facet Greiser, Sebastian
Gluth, Gregor J. G.
Sturm, Patrick
Jäger, Christian
author_sort Greiser, Sebastian
collection PubMed
description The influence of starting materials and synthesis route on the properties and the structure of cementitious sodium aluminosilicate gels is not fully understood, partly due their amorphous nature and the fact that they often contain residual reactants, which can make the results of single-pulse NMR spectroscopy applied to these materials difficult to interpret or ambiguous. To overcome some of these limitations, (29)Si{(27)Al} TRAPDOR NMR as well as (27)Al{(29)Si} and (27)Al{(1)H} REDOR NMR spectroscopy were applied to materials synthesized by the one-part alkali-activation route from three different amorphous silica starting materials, including rice husk ash. The latter led to formation of a fully amorphous sodium aluminosilicate gel (geopolymer), while the materials produced from the other silicas contained amorphous phase and crystalline zeolites. Application of the double-resonance NMR methods allowed to identify hydrous alumina gel domains in the rice husk ash-based material as well as significantly differing amounts of residual silica in the three cured materials. Four-coordinated Al existed not only in the aluminosilicate gel framework but also in a water-rich chemical environment with only a small amount of Si in proximity, likely in the alumina gel or possibly present as extra-framework Al in the aluminosilicate gel. The results demonstrate how the employment of different silica starting materials determines the phase assemblage of one-part alkali-activated materials, which in turn influences their engineering properties such as the resistance against chemically/biologically aggressive media.
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spelling pubmed-90912872022-05-11 (29)Si{(27)Al}, (27)Al{(29)Si} and (27)Al{(1)H} double-resonance NMR spectroscopy study of cementitious sodium aluminosilicate gels (geopolymers) and gel–zeolite composites Greiser, Sebastian Gluth, Gregor J. G. Sturm, Patrick Jäger, Christian RSC Adv Chemistry The influence of starting materials and synthesis route on the properties and the structure of cementitious sodium aluminosilicate gels is not fully understood, partly due their amorphous nature and the fact that they often contain residual reactants, which can make the results of single-pulse NMR spectroscopy applied to these materials difficult to interpret or ambiguous. To overcome some of these limitations, (29)Si{(27)Al} TRAPDOR NMR as well as (27)Al{(29)Si} and (27)Al{(1)H} REDOR NMR spectroscopy were applied to materials synthesized by the one-part alkali-activation route from three different amorphous silica starting materials, including rice husk ash. The latter led to formation of a fully amorphous sodium aluminosilicate gel (geopolymer), while the materials produced from the other silicas contained amorphous phase and crystalline zeolites. Application of the double-resonance NMR methods allowed to identify hydrous alumina gel domains in the rice husk ash-based material as well as significantly differing amounts of residual silica in the three cured materials. Four-coordinated Al existed not only in the aluminosilicate gel framework but also in a water-rich chemical environment with only a small amount of Si in proximity, likely in the alumina gel or possibly present as extra-framework Al in the aluminosilicate gel. The results demonstrate how the employment of different silica starting materials determines the phase assemblage of one-part alkali-activated materials, which in turn influences their engineering properties such as the resistance against chemically/biologically aggressive media. The Royal Society of Chemistry 2018-12-07 /pmc/articles/PMC9091287/ /pubmed/35558254 http://dx.doi.org/10.1039/c8ra09246j Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by/3.0/
spellingShingle Chemistry
Greiser, Sebastian
Gluth, Gregor J. G.
Sturm, Patrick
Jäger, Christian
(29)Si{(27)Al}, (27)Al{(29)Si} and (27)Al{(1)H} double-resonance NMR spectroscopy study of cementitious sodium aluminosilicate gels (geopolymers) and gel–zeolite composites
title (29)Si{(27)Al}, (27)Al{(29)Si} and (27)Al{(1)H} double-resonance NMR spectroscopy study of cementitious sodium aluminosilicate gels (geopolymers) and gel–zeolite composites
title_full (29)Si{(27)Al}, (27)Al{(29)Si} and (27)Al{(1)H} double-resonance NMR spectroscopy study of cementitious sodium aluminosilicate gels (geopolymers) and gel–zeolite composites
title_fullStr (29)Si{(27)Al}, (27)Al{(29)Si} and (27)Al{(1)H} double-resonance NMR spectroscopy study of cementitious sodium aluminosilicate gels (geopolymers) and gel–zeolite composites
title_full_unstemmed (29)Si{(27)Al}, (27)Al{(29)Si} and (27)Al{(1)H} double-resonance NMR spectroscopy study of cementitious sodium aluminosilicate gels (geopolymers) and gel–zeolite composites
title_short (29)Si{(27)Al}, (27)Al{(29)Si} and (27)Al{(1)H} double-resonance NMR spectroscopy study of cementitious sodium aluminosilicate gels (geopolymers) and gel–zeolite composites
title_sort (29)si{(27)al}, (27)al{(29)si} and (27)al{(1)h} double-resonance nmr spectroscopy study of cementitious sodium aluminosilicate gels (geopolymers) and gel–zeolite composites
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9091287/
https://www.ncbi.nlm.nih.gov/pubmed/35558254
http://dx.doi.org/10.1039/c8ra09246j
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