通过完全灵活的分子模拟预测ZIF-8中的轻碳化合物的温度和负载依赖的扩散
Ross J Verploegh1, Sankar Nair1, David S Sholl1
1School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0100, United States.
Journal of the American Chemical Society
|November 26, 2015
概括
使用动态校正过渡状态理论 (dcTST) 实现了ZIF-8中碳化合物扩散的准确预测. 这种方法可以解释材料的灵活性,并成功模拟各种碳化合物负载和温度的扩散.
科学领域:
- 材料科学
- 化学工程
- 计算化学
背景情况:
- 由于孔径小且扩散时间不同,难以准确地预测化物扩散在化物模酸框架 (ZIF) 中,特别是ZIF-8.
- 了解扩散对于设计ZIF用于气体分离和储存应用至关重要.
研究的目的:
- 通过计算测量跳跃率并预测ZIF-8中的碳化合物扩散率.
- 研究ZIF-8灵活性和碳化合物负载对扩散系数的影响.
主要方法:
- 用动态校正过渡状态理论 (dcTST) 来计算跳跃率.
- 使用雨采样和权重组图分析方法 (WHAM) 来确定无扩散能障碍.
- 在总体抽样和动态校正计算中考虑了ZIF-8的灵活性.
主要成果:
- 计算的扩散性显示出与15种不同分子的实验数据具有显著的一致性.
- 这项研究成功地模拟了从无限稀释到类似液体的各种碳化合物载荷的扩散.
- 各种碳化合物的自我和运输扩散系数在0-150°C的温度范围内报告.
结论:
- 动态校正过渡状态理论 (dcTST) 提供了ZIF-8中碳化合物扩散的准确预测.
- 考虑ZIF-8的灵活性对于精确的扩散建模至关重要.
- 开发的方法适用于在不同条件下研究扩散,有助于ZIF材料设计.
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