Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach.
Dissolution of Portlandite in Pure Water: Part 2 Atomistic Kinetic Monte Carlo (KMC) Approach.
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DOI：
10.3390/ma15041442
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发表时间：
2022-02-15
期刊：
影响因子：
--
通讯作者：
Koenders E
中科院分区：
文献类型：
--
作者：
Izadifar M;Ukrainczyk N;Salah Uddin KM;Middendorf B;Koenders E
波特兰石作为一种最易溶解的水泥水化反应产物，直接影响胶凝材料的力学性能和耐久性能。本文采用原子动力学蒙特卡罗(KMC)方法，在MatLab程序中模拟了六方片状紫柱石晶体的溶解时间和形貌变化。首先，根据通过元动力学计算方法得到的活化能(ΔG*)的输入，通过过渡态理论方程计算了单个钙溶解事件的原子速率常数(论文第一部分)。考虑了四个不同的方面(100或、010或00、或001或00)，总共产生了16个不同的原子事件场景。放大的KMC模拟结果表明，溶解过程最初发生在晶体形态的010或00的边、边和小面上。结果表明，活化度最高的面(010或0)的稳态溶出度为1.0443摩尔/(S厘米~2)，而活化度较低的面的溶出度依次为0.0032摩尔/(S厘米~2)、2.672×10~(7)−/(S厘米~2)和0.31×10~(16)−/(S厘米~2)。得到的每个面之间的溶解速率的放大导致了巨大的(16个数量级)的差异，反映了暴露的面的晶体取向的重要性。
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 , 010 or 00, or , and 001 or 00) 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 00 of the crystal morphology. The steady-state dissolution rate for the most reactive facets (010 or 0) was computed to be 1.0443 mol/(s cm2); however, 0.0032 mol/(s cm2) for or , 2.672 × 10−7 mol/(s cm2) for 001 or 00, and 0.31 × 10−16 mol/(s cm2) for 100 or 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.
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影响因子：
3.7
作者：
Kresse, G;Furthmuller, J
通讯作者：
Furthmuller, J
影响因子：
3.7
作者：
MONKHORST, HJ;PACK, JD
通讯作者：
PACK, JD
影响因子：
11.4
作者：
Galmarini, Sandra;Aimable, Anne;Bowen, Paul
通讯作者：
Bowen, Paul
DOI：
10.3390/nano11092236
发表时间：
2021-08-30
期刊：
Nanomaterials (Basel, Switzerland)
影响因子：
--
作者：
Ren K;Zheng R;Xu P;Cheng D;Huo W;Yu J;Zhang Z;Sun Q
通讯作者：
Sun Q
影响因子：
3.4
作者：
Martin, Pablo;Gaitero, Juan J.;Manzano, Hegoi
通讯作者：
Manzano, Hegoi