Atomic-scale characterisation of sodium aluminosilicate hydrates (N-A-S-H) and Mg-substituted N(-M)-A-S-H using XANES

Xinyuan Ke; Jiaqi Li; Vahiddin Baki; Alexander Large; Georg Held

doi:10.1016/j.apgeochem.2022.105515

Atomic-scale characterisation of sodium aluminosilicate hydrates (N-A-S-H) and Mg-substituted N(-M)-A-S-H using XANES

Xinyuan Ke, Jiaqi Li, Vahiddin Baki, Alexander Large, Georg Held

Research output: Contribution to journal › Article › peer-review

7 Citations (SciVal)

Abstract

The chemical structures of aluminosilicate hydrates presented in alkali-activated geopolymer materials underpin their performances. Mg-substituted sodium aluminosilicate hydrates (N(-M)-A-S-H) are likely to be present in alkali-activated geopolymer materials prepared using MgO-containing precursors, however, their atomic-level structures remain unclear. The lack of such knowledge made it challenging to identify and distinguish N(-M)-A-S-H from complex alkali-activated geopolymer systems (i.e., alkali-activated slag, alkali-activated Mg-rich minerals), and therefore brought challenges in understanding and predicting their durability. This study characterised for the first time the atomic structures of the synthetic N(-M)-A-S-H gels, prepared through ion-exchange or co-synthesis, using X-ray absorption near-edge spectroscopy (XANES) at Si, Al and Mg K-edge. The results suggest that the substitution of Mg in the extra-framework locations of the alkali aluminosilicate hydrates (N-A-S-H) leads to negligible changes in the coordination environments of the aluminosilicate framework. However, the Mg coordination environment is distinguishably different from other Mg-containing phases in the systems, e.g., hydrotalcite. The Mg K-edge XANES of N(-M)-A-S-H shows a 0.8–1.2 eV shift compared with hydrotalcite. The results presented in this study can be used as the fingerprint to probe the presence of N(-M)-A-S-H in alkali-activated geopolymer materials containing Mg element.

Original language	English
Article number	105515
Journal	Applied Geochemistry
Volume	147
Early online date	12 Nov 2022
DOIs	https://doi.org/10.1016/j.apgeochem.2022.105515
Publication status	Published - 31 Dec 2022

Bibliographical note

EPSRC
EP/W010828/1
Diamond Light Source Ltd
Proposal SI28470
University of Bath
Prize Fellowship
Lawrence Livermore National Laboratory
21ERD050

Funding Information:
This work was carried out with the support of Diamond Light Source, instrument B07 (proposal SI28470). This research was partially funded by the UK Engineering and Physical Sciences Research Council (EPSRC) through Grant EP/W010828/1. The participation of XK was partially funded by the University of Bath Prize Fellowship (2018–2021). The participation of JL was under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory (contract No. DE-AC52-07NA27344), with LLNL IM release number LLNL-JRNL-833223. The authors would also like to thank Imerys (UK) for supplying metakaolin materials for this study. The authors would also like to acknowledge Dr Daniel Geddes, The University of Sheffield, for assisting the collection of 29Si solid-state MAS NMR data (included in Supplementary data).

Funding Information:
This work was carried out with the support of Diamond Light Source , instrument B07 (proposal SI28470 ). This research was partially funded by the UK Engineering and Physical Sciences Research Council (EPSRC) through Grant EP/W010828/1 . The participation of XK was partially funded by the University of Bath Prize Fellowship (2018–2021). The participation of JL was under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory (contract No. DE-AC52-07NA27344), with LLNL IM release number LLNL-JRNL-833223. The authors would also like to thank Imerys (UK) for supplying metakaolin materials for this study. The authors would also like to acknowledge Dr Daniel Geddes, The University of Sheffield, for assisting the collection of 29 Si solid-state MAS NMR data (included in Supplementary data).

Keywords

Alkali-activated geopolymer materials
Amorphous material
Atomic-level characterization
X-ray absorption spectroscopy

ASJC Scopus subject areas

Environmental Chemistry
Pollution
Geochemistry and Petrology

Access to Document

10.1016/j.apgeochem.2022.105515Licence: CC BY

Cite this

@article{d049bd5f2bd5424e847d5caea57a3a86,

title = "Atomic-scale characterisation of sodium aluminosilicate hydrates (N-A-S-H) and Mg-substituted N(-M)-A-S-H using XANES",

abstract = "The chemical structures of aluminosilicate hydrates presented in alkali-activated geopolymer materials underpin their performances. Mg-substituted sodium aluminosilicate hydrates (N(-M)-A-S-H) are likely to be present in alkali-activated geopolymer materials prepared using MgO-containing precursors, however, their atomic-level structures remain unclear. The lack of such knowledge made it challenging to identify and distinguish N(-M)-A-S-H from complex alkali-activated geopolymer systems (i.e., alkali-activated slag, alkali-activated Mg-rich minerals), and therefore brought challenges in understanding and predicting their durability. This study characterised for the first time the atomic structures of the synthetic N(-M)-A-S-H gels, prepared through ion-exchange or co-synthesis, using X-ray absorption near-edge spectroscopy (XANES) at Si, Al and Mg K-edge. The results suggest that the substitution of Mg in the extra-framework locations of the alkali aluminosilicate hydrates (N-A-S-H) leads to negligible changes in the coordination environments of the aluminosilicate framework. However, the Mg coordination environment is distinguishably different from other Mg-containing phases in the systems, e.g., hydrotalcite. The Mg K-edge XANES of N(-M)-A-S-H shows a 0.8–1.2 eV shift compared with hydrotalcite. The results presented in this study can be used as the fingerprint to probe the presence of N(-M)-A-S-H in alkali-activated geopolymer materials containing Mg element.",

keywords = "Alkali-activated geopolymer materials, Amorphous material, Atomic-level characterization, X-ray absorption spectroscopy",

author = "Xinyuan Ke and Jiaqi Li and Vahiddin Baki and Alexander Large and Georg Held",

note = "EPSRC EP/W010828/1 Diamond Light Source Ltd Proposal SI28470 University of Bath Prize Fellowship Lawrence Livermore National Laboratory 21ERD050 Funding Information: This work was carried out with the support of Diamond Light Source, instrument B07 (proposal SI28470). This research was partially funded by the UK Engineering and Physical Sciences Research Council (EPSRC) through Grant EP/W010828/1. The participation of XK was partially funded by the University of Bath Prize Fellowship (2018–2021). The participation of JL was under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory (contract No. DE-AC52-07NA27344), with LLNL IM release number LLNL-JRNL-833223. The authors would also like to thank Imerys (UK) for supplying metakaolin materials for this study. The authors would also like to acknowledge Dr Daniel Geddes, The University of Sheffield, for assisting the collection of 29Si solid-state MAS NMR data (included in Supplementary data). Funding Information: This work was carried out with the support of Diamond Light Source , instrument B07 (proposal SI28470 ). This research was partially funded by the UK Engineering and Physical Sciences Research Council (EPSRC) through Grant EP/W010828/1 . The participation of XK was partially funded by the University of Bath Prize Fellowship (2018–2021). The participation of JL was under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory (contract No. DE-AC52-07NA27344), with LLNL IM release number LLNL-JRNL-833223. The authors would also like to thank Imerys (UK) for supplying metakaolin materials for this study. The authors would also like to acknowledge Dr Daniel Geddes, The University of Sheffield, for assisting the collection of 29 Si solid-state MAS NMR data (included in Supplementary data). ",

year = "2022",

month = dec,

day = "31",

doi = "10.1016/j.apgeochem.2022.105515",

language = "English",

volume = "147",

journal = "Applied Geochemistry",

issn = "0883-2927",

publisher = "Elsevier",

}

TY - JOUR

T1 - Atomic-scale characterisation of sodium aluminosilicate hydrates (N-A-S-H) and Mg-substituted N(-M)-A-S-H using XANES

AU - Ke, Xinyuan

AU - Li, Jiaqi

AU - Baki, Vahiddin

AU - Large, Alexander

AU - Held, Georg

N1 - EPSRC EP/W010828/1 Diamond Light Source Ltd Proposal SI28470 University of Bath Prize Fellowship Lawrence Livermore National Laboratory 21ERD050 Funding Information: This work was carried out with the support of Diamond Light Source, instrument B07 (proposal SI28470). This research was partially funded by the UK Engineering and Physical Sciences Research Council (EPSRC) through Grant EP/W010828/1. The participation of XK was partially funded by the University of Bath Prize Fellowship (2018–2021). The participation of JL was under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory (contract No. DE-AC52-07NA27344), with LLNL IM release number LLNL-JRNL-833223. The authors would also like to thank Imerys (UK) for supplying metakaolin materials for this study. The authors would also like to acknowledge Dr Daniel Geddes, The University of Sheffield, for assisting the collection of 29Si solid-state MAS NMR data (included in Supplementary data). Funding Information: This work was carried out with the support of Diamond Light Source , instrument B07 (proposal SI28470 ). This research was partially funded by the UK Engineering and Physical Sciences Research Council (EPSRC) through Grant EP/W010828/1 . The participation of XK was partially funded by the University of Bath Prize Fellowship (2018–2021). The participation of JL was under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory (contract No. DE-AC52-07NA27344), with LLNL IM release number LLNL-JRNL-833223. The authors would also like to thank Imerys (UK) for supplying metakaolin materials for this study. The authors would also like to acknowledge Dr Daniel Geddes, The University of Sheffield, for assisting the collection of 29 Si solid-state MAS NMR data (included in Supplementary data).

PY - 2022/12/31

Y1 - 2022/12/31

N2 - The chemical structures of aluminosilicate hydrates presented in alkali-activated geopolymer materials underpin their performances. Mg-substituted sodium aluminosilicate hydrates (N(-M)-A-S-H) are likely to be present in alkali-activated geopolymer materials prepared using MgO-containing precursors, however, their atomic-level structures remain unclear. The lack of such knowledge made it challenging to identify and distinguish N(-M)-A-S-H from complex alkali-activated geopolymer systems (i.e., alkali-activated slag, alkali-activated Mg-rich minerals), and therefore brought challenges in understanding and predicting their durability. This study characterised for the first time the atomic structures of the synthetic N(-M)-A-S-H gels, prepared through ion-exchange or co-synthesis, using X-ray absorption near-edge spectroscopy (XANES) at Si, Al and Mg K-edge. The results suggest that the substitution of Mg in the extra-framework locations of the alkali aluminosilicate hydrates (N-A-S-H) leads to negligible changes in the coordination environments of the aluminosilicate framework. However, the Mg coordination environment is distinguishably different from other Mg-containing phases in the systems, e.g., hydrotalcite. The Mg K-edge XANES of N(-M)-A-S-H shows a 0.8–1.2 eV shift compared with hydrotalcite. The results presented in this study can be used as the fingerprint to probe the presence of N(-M)-A-S-H in alkali-activated geopolymer materials containing Mg element.

AB - The chemical structures of aluminosilicate hydrates presented in alkali-activated geopolymer materials underpin their performances. Mg-substituted sodium aluminosilicate hydrates (N(-M)-A-S-H) are likely to be present in alkali-activated geopolymer materials prepared using MgO-containing precursors, however, their atomic-level structures remain unclear. The lack of such knowledge made it challenging to identify and distinguish N(-M)-A-S-H from complex alkali-activated geopolymer systems (i.e., alkali-activated slag, alkali-activated Mg-rich minerals), and therefore brought challenges in understanding and predicting their durability. This study characterised for the first time the atomic structures of the synthetic N(-M)-A-S-H gels, prepared through ion-exchange or co-synthesis, using X-ray absorption near-edge spectroscopy (XANES) at Si, Al and Mg K-edge. The results suggest that the substitution of Mg in the extra-framework locations of the alkali aluminosilicate hydrates (N-A-S-H) leads to negligible changes in the coordination environments of the aluminosilicate framework. However, the Mg coordination environment is distinguishably different from other Mg-containing phases in the systems, e.g., hydrotalcite. The Mg K-edge XANES of N(-M)-A-S-H shows a 0.8–1.2 eV shift compared with hydrotalcite. The results presented in this study can be used as the fingerprint to probe the presence of N(-M)-A-S-H in alkali-activated geopolymer materials containing Mg element.

KW - Alkali-activated geopolymer materials

KW - Amorphous material

KW - Atomic-level characterization

KW - X-ray absorption spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=85142192569&partnerID=8YFLogxK

U2 - 10.1016/j.apgeochem.2022.105515

DO - 10.1016/j.apgeochem.2022.105515

M3 - Article

SN - 0883-2927

VL - 147

JO - Applied Geochemistry

JF - Applied Geochemistry

M1 - 105515

ER -

Atomic-scale characterisation of sodium aluminosilicate hydrates (N-A-S-H) and Mg-substituted N(-M)-A-S-H using XANES

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

High-performance carbon-neutral Geopolymer heat Battery for thermochemical energy storage in net-zero buildings

Avance III 500 MHz Nuclear Magnetic Resonance (NMR) Spectrometer (9West)

Avance NEO 500 MHz Nuclear Magnetic Resonance (NMR) Spectrometer (1South)

Large chamber variable pressure scanning electron microscope (SEM)

Cite this

Atomic-scale characterisation of sodium aluminosilicate hydrates (N-A-S-H) and Mg-substituted N(-M)-A-S-H using XANES

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Projects

High-performance carbon-neutral Geopolymer heat Battery for thermochemical energy storage in net-zero buildings

Equipment

Avance III 500 MHz Nuclear Magnetic Resonance (NMR) Spectrometer (9West)

Avance NEO 500 MHz Nuclear Magnetic Resonance (NMR) Spectrometer (1South)

Large chamber variable pressure scanning electron microscope (SEM)

Cite this