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Silicate Dissolution Mechanism from Metakaolinite Using Density Functional Theory
Metakaolin (MK) is a high-quality, reactive nanomaterial that holds promising potential for large-scale use in improving the sustainability of cement and concrete production. It can replace cement due to its pozzolanic reaction with calcium hydroxide and water to form cementitious compounds. Therefo...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10096740/ https://www.ncbi.nlm.nih.gov/pubmed/37049290 http://dx.doi.org/10.3390/nano13071196 |
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author | Izadifar, Mohammadreza Ukrainczyk, Neven Koenders, Eduardus |
author_facet | Izadifar, Mohammadreza Ukrainczyk, Neven Koenders, Eduardus |
author_sort | Izadifar, Mohammadreza |
collection | PubMed |
description | Metakaolin (MK) is a high-quality, reactive nanomaterial that holds promising potential for large-scale use in improving the sustainability of cement and concrete production. It can replace cement due to its pozzolanic reaction with calcium hydroxide and water to form cementitious compounds. Therefore, understanding the dissolution mechanism is crucial to fully comprehending its pozzolanic reactivity. In this study, we present an approach for computing the activation energies required for the dissolution of metakaolin (MK) silicate units at far-from-equilibrium conditions using the improved dimer method (IDM) and the transition-state theory (TST) within density functional theory (DFT). Four different models were prepared to calculate the activation energies required for breaking oxo-bridging bonds between silicate or aluminate units. Our results showed that the activation energy for breaking the oxo-bridging bond to a silicate neighbor is higher than that to an aluminate neighbor due to the ionic interaction. However, for complete silicate tetrahedra dissolution, a higher activation energy is required for breaking the oxo-bridging bond to the aluminate neighbor compared to the silicate neighbor. The findings provide methodology for missing input data to predict the mesoscopic dissolution rate, e.g., by the atomistic kinetic Monte Carlo (KMC) upscaling approach. |
format | Online Article Text |
id | pubmed-10096740 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-100967402023-04-13 Silicate Dissolution Mechanism from Metakaolinite Using Density Functional Theory Izadifar, Mohammadreza Ukrainczyk, Neven Koenders, Eduardus Nanomaterials (Basel) Article Metakaolin (MK) is a high-quality, reactive nanomaterial that holds promising potential for large-scale use in improving the sustainability of cement and concrete production. It can replace cement due to its pozzolanic reaction with calcium hydroxide and water to form cementitious compounds. Therefore, understanding the dissolution mechanism is crucial to fully comprehending its pozzolanic reactivity. In this study, we present an approach for computing the activation energies required for the dissolution of metakaolin (MK) silicate units at far-from-equilibrium conditions using the improved dimer method (IDM) and the transition-state theory (TST) within density functional theory (DFT). Four different models were prepared to calculate the activation energies required for breaking oxo-bridging bonds between silicate or aluminate units. Our results showed that the activation energy for breaking the oxo-bridging bond to a silicate neighbor is higher than that to an aluminate neighbor due to the ionic interaction. However, for complete silicate tetrahedra dissolution, a higher activation energy is required for breaking the oxo-bridging bond to the aluminate neighbor compared to the silicate neighbor. The findings provide methodology for missing input data to predict the mesoscopic dissolution rate, e.g., by the atomistic kinetic Monte Carlo (KMC) upscaling approach. MDPI 2023-03-27 /pmc/articles/PMC10096740/ /pubmed/37049290 http://dx.doi.org/10.3390/nano13071196 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Izadifar, Mohammadreza Ukrainczyk, Neven Koenders, Eduardus Silicate Dissolution Mechanism from Metakaolinite Using Density Functional Theory |
title | Silicate Dissolution Mechanism from Metakaolinite Using Density Functional Theory |
title_full | Silicate Dissolution Mechanism from Metakaolinite Using Density Functional Theory |
title_fullStr | Silicate Dissolution Mechanism from Metakaolinite Using Density Functional Theory |
title_full_unstemmed | Silicate Dissolution Mechanism from Metakaolinite Using Density Functional Theory |
title_short | Silicate Dissolution Mechanism from Metakaolinite Using Density Functional Theory |
title_sort | silicate dissolution mechanism from metakaolinite using density functional theory |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10096740/ https://www.ncbi.nlm.nih.gov/pubmed/37049290 http://dx.doi.org/10.3390/nano13071196 |
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