Izadifar, Mohammadreza ; Ukrainczyk, Neven ; Salah Uddin, Khondakar Mohammad ; Middendorf, Bernhard ; Koenders, Eduardus (2022)
Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach.
In: Materials, 2022, 15 (4)
doi: 10.26083/tuprints-00021020
Artikel, Zweitveröffentlichung, Verlagsversion
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Kurzbeschreibung (Abstract)
Portlandite, as a most soluble cement hydration reaction product, affects mechanical and durability properties of cementitious materials. In the present work, an atomistic kinetic Monte Carlo (KMC) upscaling approach is implemented in MATLAB code in order to investigate the dissolution time and morphology changes of a hexagonal platelet portlandite crystal. First, the atomistic rate constants of individual Ca dissolution events are computed by a transition state theory equation based on inputs of the computed activation energies (ΔG*) obtained through the metadynamics computational method (Part 1 of paper). Four different facets (100 or 1¯00 , 010 or 01¯0, 1¯10 or 11¯0, and 001 or 001¯) are considered, resulting in a total of 16 different atomistic event scenarios. Results of the upscaled KMC simulations demonstrate that dissolution process initially takes place from edges, sides, and facets of 010 or 01¯0 of the crystal morphology. The steady-state dissolution rate for the most reactive facets (010 or 01¯0) was computed to be 1.0443 mol/(s cm²); however, 0.0032 mol/(s cm²) for 1¯10 or 11¯0, 2.672 × 10⁻⁷ mol/(s cm²) for 001 or 001¯, and 0.31 × 10⁻¹⁶ mol/(s cm²) for 100 or 1¯00 were represented in a decreasing order for less reactive facets. Obtained upscaled dissolution rates between each facet resulted in a huge (16 orders of magnitude) difference, reflecting the importance of crystallographic orientation of the exposed facets.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2022 |
| Autor(en): | Izadifar, Mohammadreza ; Ukrainczyk, Neven ; Salah Uddin, Khondakar Mohammad ; Middendorf, Bernhard ; Koenders, Eduardus |
| Art des Eintrags: | Zweitveröffentlichung |
| Titel: | Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach |
| Sprache: | Englisch |
| Publikationsjahr: | 2022 |
| Publikationsdatum der Erstveröffentlichung: | 2022 |
| Verlag: | MDPI |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Materials |
| Jahrgang/Volume einer Zeitschrift: | 15 |
| (Heft-)Nummer: | 4 |
| Kollation: | 17 Seiten |
| DOI: | 10.26083/tuprints-00021020 |
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/21020 |
| Zugehörige Links: | |
| Herkunft: | Zweitveröffentlichung DeepGreen |
| Kurzbeschreibung (Abstract): | Portlandite, as a most soluble cement hydration reaction product, affects mechanical and durability properties of cementitious materials. In the present work, an atomistic kinetic Monte Carlo (KMC) upscaling approach is implemented in MATLAB code in order to investigate the dissolution time and morphology changes of a hexagonal platelet portlandite crystal. First, the atomistic rate constants of individual Ca dissolution events are computed by a transition state theory equation based on inputs of the computed activation energies (ΔG*) obtained through the metadynamics computational method (Part 1 of paper). Four different facets (100 or 1¯00 , 010 or 01¯0, 1¯10 or 11¯0, and 001 or 001¯) are considered, resulting in a total of 16 different atomistic event scenarios. Results of the upscaled KMC simulations demonstrate that dissolution process initially takes place from edges, sides, and facets of 010 or 01¯0 of the crystal morphology. The steady-state dissolution rate for the most reactive facets (010 or 01¯0) was computed to be 1.0443 mol/(s cm²); however, 0.0032 mol/(s cm²) for 1¯10 or 11¯0, 2.672 × 10⁻⁷ mol/(s cm²) for 001 or 001¯, and 0.31 × 10⁻¹⁶ mol/(s cm²) for 100 or 1¯00 were represented in a decreasing order for less reactive facets. Obtained upscaled dissolution rates between each facet resulted in a huge (16 orders of magnitude) difference, reflecting the importance of crystallographic orientation of the exposed facets. |
| Freie Schlagworte: | portlandite, calcium hydroxide, atomistic kinetic Monte Carlo, upscaling approach, dissolution rate |
| Status: | Verlagsversion |
| URN: | urn:nbn:de:tuda-tuprints-210206 |
| Zusätzliche Informationen: | Part 1: urn:nbn:de:tuda-tuprints-210215 |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 540 Chemie 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften und Maschinenbau |
| Fachbereich(e)/-gebiet(e): | 13 Fachbereich Bau- und Umweltingenieurwissenschaften 13 Fachbereich Bau- und Umweltingenieurwissenschaften > Institut für Werkstoffe im Bauwesen |
| Hinterlegungsdatum: | 11 Apr 2022 11:19 |
| Letzte Änderung: | 12 Apr 2022 06:40 |
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| Suche nach Titel in: | TUfind oder in Google |
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- Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach. (deposited 11 Apr 2022 11:19) [Gegenwärtig angezeigt]
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