Abstract
This study presents for the first time a systematic investigation of the thermodynamic properties of sodium aluminosilicate hydrate (N-A-S-H), through dissolution of pure synthetic N-A-S-H gels. Changes to the chemical composition and gel structure of N-A-S-H were determinedviacharacterisation of the solid phase before and after dissolution by multinuclear solid state nuclear magnetic resonance spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, and X-ray diffraction measurements. The correlations between the bulk Si/Al ratio of the N-A-S-H phase and its thermodynamic properties were studied by characterisation of the aqueous phase and calculation of solubility constants. The solubility of synthetic N-A-S-H was compared with the solubility of metakaolin-based geopolymers with similar bulk Si/Al ratios. The solubility (log10 Ksp) of both the synthetic N-A-S-H gels and metakaolin-based geopolymers showed a close to linear correlation with the bulk Si/Al ratio of the phase. Lower solubility was observed for N-A-S-H gels and geopolymers with a higher bulk Si/Al ratio. This new insight is fundamental to understanding the physiochemical properties of geopolymers, and provides essential information for predicting their long-term stability and durability.
| Original language | English |
|---|---|
| Pages (from-to) | 13968-13984 |
| Number of pages | 17 |
| Journal | Dalton Transactions |
| Volume | 50 |
| Issue number | 39 |
| Early online date | 7 Sept 2021 |
| DOIs | |
| Publication status | Published - 21 Oct 2021 |
Bibliographical note
Funding Information:This work has been funded by the Engineering and Physical Sciences Research Council (EPSRC), UK, through grant EP/ P013171/1. The participation of XK was partly sponsored by a University of Bath Prize Fellowship. We wish to thank and acknowledge Professor Susan Bernal, School of Civil Engineering, The University of Leeds, for insightful discussions related to this work. We also wish to thank and acknowledge Dr Sandra van Meurs, Department of Chemistry, The University of Sheffield, for assistance in acquiring the NMR data and insightful discussions related to this work. We are also very grateful to the PQ Corporation for the provision of alkali silicate solutions for this experimental programme.
Funding Information:
This work has been funded by the Engineering and Physical Sciences Research Council (EPSRC), UK, through grant EP/P013171/1. The participation of XK was partly sponsored by a University of Bath Prize Fellowship. We wish to thank and acknowledge Professor Susan Bernal, School of Civil Engineering, The University of Leeds, for insightful discussions related to this work. We also wish to thank and acknowledge Dr Sandra van Meurs, Department of Chemistry, The University of Sheffield, for assistance in acquiring the NMR data and insightful discussions related to this work. We are also very grateful to the PQ Corporation for the provision of alkali silicate solutions for this experimental programme.
Funding
This work has been funded by the Engineering and Physical Sciences Research Council (EPSRC), UK, through grant EP/ P013171/1. The participation of XK was partly sponsored by a University of Bath Prize Fellowship. We wish to thank and acknowledge Professor Susan Bernal, School of Civil Engineering, The University of Leeds, for insightful discussions related to this work. We also wish to thank and acknowledge Dr Sandra van Meurs, Department of Chemistry, The University of Sheffield, for assistance in acquiring the NMR data and insightful discussions related to this work. We are also very grateful to the PQ Corporation for the provision of alkali silicate solutions for this experimental programme. This work has been funded by the Engineering and Physical Sciences Research Council (EPSRC), UK, through grant EP/P013171/1. The participation of XK was partly sponsored by a University of Bath Prize Fellowship. We wish to thank and acknowledge Professor Susan Bernal, School of Civil Engineering, The University of Leeds, for insightful discussions related to this work. We also wish to thank and acknowledge Dr Sandra van Meurs, Department of Chemistry, The University of Sheffield, for assistance in acquiring the NMR data and insightful discussions related to this work. We are also very grateful to the PQ Corporation for the provision of alkali silicate solutions for this experimental programme.
ASJC Scopus subject areas
- Inorganic Chemistry
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