101. Molecular Dynamics Simulation of CO2Uptake in NKPOC-1: Understanding the Temperature-Dependent Multistep Adsorption in Soft Porous Molecular Crystal
- Author
-
Yang, Lan, Zheng, Han, Mei, Wei, Wang, Zhifang, Zhang, Zhenjie, and Yu, Kuang
- Abstract
Soft porous crystals (SPCs) are novel porous materials that exhibit significant global crystal structure deformations under external stimuli. The crystal structure deformation brings strong switch effects and hysteresis effects, which can be used to achieve highly selective separations for similar gas molecules. Among SPCs, soft porous organic cages (POCs) are particularly interesting due to their unique advantages in stability and processability. The soft nonbonding interactions in POCs lead to more delicate structural deformations and complicated sorption isotherms. Therefore, compared to rigid porous materials, it is more difficult to understand, predict, and rationally control the gas uptakes of POCs. In this work, we advance this field by employing a hybrid Grand Canonical Monte Carlo/Molecular Dynamics strategy to investigate the unique sorption behavior of a POC, named NKPOC-1, upon exposure to CO2. The experimental multistep sorption isotherms with large hysteresis at different temperatures are well reproduced. We further elucidate the distinct sorption and crystal structure deformation mechanisms at different temperatures, demonstrating the unusual complexity of POC gas adsorption. To the best of our knowledge, this is the first thorough theoretical study of understanding the sorption mechanism of soft POCs. Also, the methodology used in this work provides a generally effective way to simulate the adsorption behaviors in highly flexible materials.
- Published
- 2024
- Full Text
- View/download PDF