Investigation for Carbonation Mechanism of Tobermorite 9 Å: A Combination of DFT and Ab Initio Molecular Dynamics Study
Hydrated calcium silicate carbonation leads to reinforcement corrosion and strength reduction. The carbonation mechanism of Tobermorite 9 Å is researched by density functional theory calculation and ab initio molecular dynamics (AIMD). Results show that the lowest surface energy of Tobermorite 9 Å (...
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Published in | Advanced theory and simulations Vol. 6; no. 1 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
01.01.2023
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Subjects | |
Online Access | Get full text |
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Summary: | Hydrated calcium silicate carbonation leads to reinforcement corrosion and strength reduction. The carbonation mechanism of Tobermorite 9 Å is researched by density functional theory calculation and ab initio molecular dynamics (AIMD). Results show that the lowest surface energy of Tobermorite 9 Å (001) slab is (001) surface. The bridge position of Ca1─Ca5 atom is the most stable adsorption position for carbon dioxide molecules. In terms of charge density difference, the results show that the Ca atom loses electrons and the O atom gains electrons. In terms of partial density of states, the results show that there are unobvious hybridization orbitals between Ca d‐ and O p‐orbitals, which leads to the formation of a very weak Ca─O bond. In terms of AIMD simulation at the temperature of 1073 K, the results show that the carbon dioxide gradually develops from adsorption to desorption on the Tobermorite 9 Å (001) surface. These findings provide profound views in understanding the carbonation of hydrated calcium silicate.
The lowest surface energy of Tobermorite 9 Å (001) slab is (001) surface. The bridge position of Ca1─Ca5 atom is the most stable adsorption position for CO2. In the charge density difference, the Ca atom loses electrons and the O atom gains electrons. In the ab initio molecular dynamics, the CO2 gradually develops from adsorption to desorption at 1073 K. |
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ISSN: | 2513-0390 2513-0390 |
DOI: | 10.1002/adts.202200729 |