Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach
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 morp...
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MDPI AG
2022-02-01
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| Online Access: | https://www.mdpi.com/1996-1944/15/4/1442 |
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| author | Mohammadreza Izadifar Neven Ukrainczyk Khondakar Mohammad Salah Uddin Bernhard Middendorf Eduardus Koenders |
| author_facet | Mohammadreza Izadifar Neven Ukrainczyk Khondakar Mohammad Salah Uddin Bernhard Middendorf Eduardus Koenders |
| author_sort | Mohammadreza Izadifar |
| collection | DOAJ |
| description | 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 (Δ<i>G*</i>) obtained through the metadynamics computational method (Part 1 of paper). Four different facets (100 or <inline-formula><math display="inline"><semantics><mrow><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>00</mn></mrow></semantics></math></inline-formula>, 010 or 0<inline-formula><math display="inline"><semantics><mover accent="true"><mn>1</mn><mo>¯</mo></mover></semantics></math></inline-formula>0, <inline-formula><math display="inline"><semantics><mrow><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>10</mn></mrow></semantics></math></inline-formula> or <inline-formula><math display="inline"><semantics><mrow><mn>1</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>0</mn></mrow></semantics></math></inline-formula>, and 001 or 00<inline-formula><math display="inline"><semantics><mover accent="true"><mn>1</mn><mo>¯</mo></mover></semantics></math></inline-formula>) 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 0<inline-formula><math display="inline"><semantics><mover accent="true"><mn>1</mn><mo>¯</mo></mover></semantics></math></inline-formula>0 of the crystal morphology. The steady-state dissolution rate for the most reactive facets (010 or 0<inline-formula><math display="inline"><semantics><mrow><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>0</mn></mrow></semantics></math></inline-formula>) was computed to be 1.0443 mol/(s cm<sup>2</sup>); however, 0.0032 mol/(s cm<sup>2</sup>) for <inline-formula><math display="inline"><semantics><mrow><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>10</mn></mrow></semantics></math></inline-formula> or <inline-formula><math display="inline"><semantics><mrow><mn>1</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>0</mn></mrow></semantics></math></inline-formula>, 2.672 × 10<sup>−7</sup> mol/(s cm<sup>2</sup>) for 001 or 00<inline-formula><math display="inline"><semantics><mover accent="true"><mn>1</mn><mo>¯</mo></mover></semantics></math></inline-formula>, and 0.31 × 10<sup>−16</sup> mol/(s cm<sup>2</sup>) for 100 or <inline-formula><math display="inline"><semantics><mrow><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>00</mn></mrow></semantics></math></inline-formula> 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. |
| first_indexed | 2024-03-09T21:32:36Z |
| format | Article |
| id | doaj.art-9c79911d5ed247cd9ce12a937e7511e2 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T21:32:36Z |
| publishDate | 2022-02-01 |
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| series | Materials |
| spelling | doaj.art-9c79911d5ed247cd9ce12a937e7511e22023-11-23T20:53:18ZengMDPI AGMaterials1996-19442022-02-01154144210.3390/ma15041442Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) ApproachMohammadreza Izadifar0Neven Ukrainczyk1Khondakar Mohammad Salah Uddin2Bernhard Middendorf3Eduardus Koenders4Institute of Construction and Building Materials, Technical University of Darmstadt, Franziska-Braun-Str. 3, 64287 Darmstadt, GermanyInstitute of Construction and Building Materials, Technical University of Darmstadt, Franziska-Braun-Str. 3, 64287 Darmstadt, GermanyDepartment of Structural Materials and Construction Chemistry, University of Kassel, Mönchebergstraße 7, 34125 Kassel, GermanyDepartment of Structural Materials and Construction Chemistry, University of Kassel, Mönchebergstraße 7, 34125 Kassel, GermanyInstitute of Construction and Building Materials, Technical University of Darmstadt, Franziska-Braun-Str. 3, 64287 Darmstadt, GermanyPortlandite, 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 (Δ<i>G*</i>) obtained through the metadynamics computational method (Part 1 of paper). Four different facets (100 or <inline-formula><math display="inline"><semantics><mrow><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>00</mn></mrow></semantics></math></inline-formula>, 010 or 0<inline-formula><math display="inline"><semantics><mover accent="true"><mn>1</mn><mo>¯</mo></mover></semantics></math></inline-formula>0, <inline-formula><math display="inline"><semantics><mrow><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>10</mn></mrow></semantics></math></inline-formula> or <inline-formula><math display="inline"><semantics><mrow><mn>1</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>0</mn></mrow></semantics></math></inline-formula>, and 001 or 00<inline-formula><math display="inline"><semantics><mover accent="true"><mn>1</mn><mo>¯</mo></mover></semantics></math></inline-formula>) 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 0<inline-formula><math display="inline"><semantics><mover accent="true"><mn>1</mn><mo>¯</mo></mover></semantics></math></inline-formula>0 of the crystal morphology. The steady-state dissolution rate for the most reactive facets (010 or 0<inline-formula><math display="inline"><semantics><mrow><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>0</mn></mrow></semantics></math></inline-formula>) was computed to be 1.0443 mol/(s cm<sup>2</sup>); however, 0.0032 mol/(s cm<sup>2</sup>) for <inline-formula><math display="inline"><semantics><mrow><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>10</mn></mrow></semantics></math></inline-formula> or <inline-formula><math display="inline"><semantics><mrow><mn>1</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>0</mn></mrow></semantics></math></inline-formula>, 2.672 × 10<sup>−7</sup> mol/(s cm<sup>2</sup>) for 001 or 00<inline-formula><math display="inline"><semantics><mover accent="true"><mn>1</mn><mo>¯</mo></mover></semantics></math></inline-formula>, and 0.31 × 10<sup>−16</sup> mol/(s cm<sup>2</sup>) for 100 or <inline-formula><math display="inline"><semantics><mrow><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>00</mn></mrow></semantics></math></inline-formula> 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.https://www.mdpi.com/1996-1944/15/4/1442portlanditecalcium hydroxideatomistic kinetic Monte Carloupscaling approachdissolution rate |
| spellingShingle | Mohammadreza Izadifar Neven Ukrainczyk Khondakar Mohammad Salah Uddin Bernhard Middendorf Eduardus Koenders Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach Materials portlandite calcium hydroxide atomistic kinetic Monte Carlo upscaling approach dissolution rate |
| title | Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach |
| title_full | Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach |
| title_fullStr | Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach |
| title_full_unstemmed | Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach |
| title_short | Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach |
| title_sort | dissolution of portlandite in pure water part 2 atomistic kinetic monte carlo kmc approach |
| topic | portlandite calcium hydroxide atomistic kinetic Monte Carlo upscaling approach dissolution rate |
| url | https://www.mdpi.com/1996-1944/15/4/1442 |
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