Salah Uddin Khondakar Mohammad, Izadifar Mohammadreza, Ukrainczyk Neven, Koenders Eduardus, Middendorf Bernhard
Department of Structural Materials and Construction Chemistry, University of Kassel, Mönchebergstraße 7, 34125 Kassel, Germany.
Institute of Construction and Building Materials, Technical University of Darmstadt, Franziska-Braun-Str. 3, 64287 Darmstadt, Germany.
Materials (Basel). 2022 Feb 14;15(4):1404. doi: 10.3390/ma15041404.
The current contribution proposes a multi-scale bridging modeling approach for the dissolution of crystals to connect the atomistic scale to the (sub-) micro-scale. This is demonstrated in the example of dissolution of portlandite, as a relatively simple benchmarking example for cementitious materials. Moreover, dissolution kinetics is also important for other industrial processes, e.g., acid gas absorption and pH control. In this work, the biased molecular dynamics (metadynamics) coupled with reactive force field is employed to calculate the reaction path as a free energy surface of calcium dissolution at 298 K in water from the different crystal facets of portlandite. It is also explained why the reactivity of the (010), (100), and (11¯0) crystal facet is higher compared to the (001) facet. In addition, the influence of neighboring Ca crystal sites arrangements on the atomistic dissolution rates is explained as necessary scenarios for the upscaling. The calculated rate constants of all atomistic reaction scenarios provided an input catalog ready to be used in an upscaling kinetic Monte Carlo (KMC) approach.
本文提出了一种用于晶体溶解的多尺度桥接建模方法，以将原子尺度与（亚）微观尺度连接起来。这在钙硅石溶解的例子中得到了证明，钙硅石作为胶凝材料的一个相对简单的基准示例。此外，溶解动力学对其他工业过程也很重要，例如酸性气体吸收和pH控制。在这项工作中，采用了结合反应力场的有偏分子动力学（元动力学）来计算反应路径，即298K时水中钙硅石不同晶面钙溶解的自由能表面。文中还解释了为什么（010）、（100）和（11¯0）晶面的反应性比（001）晶面更高。此外，相邻钙晶体位点排列对原子溶解速率的影响被解释为用于尺度提升的必要情形。所有原子反应情形的计算速率常数提供了一个输入目录，可用于尺度提升的动力学蒙特卡罗（KMC）方法。
