在微孔碳中对气吸附和扩散的分子模拟,具有多孔弹性合
Kévin Potier1, Kristina Ariskina2, Amaël Obliger1,2
1CNRS, Bordeaux INP, ISM,UMR 5255, Université de Bordeaux, Talence F-33400, France.
Langmuir : the ACS journal of surfaces and colloids
|June 26, 2023
概括
微孔碳中吸附诱导的矩阵变形显著影响气体负载和扩散. 忽视这些影响可能会导致严重的低估,强调考虑物质胀和内部变化的重要性.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学的计算化学
- 化学工程是化学工程的重要组成部分.
背景情况:
- 在微孔碳中液体吸附的分子模拟历史上忽视了矩阵变形.
- 最近的研究表明,吸附诱导的矩阵变形显著影响吸附等温和和扩散系数.
- 素是一种芳香的微孔碳,可以作为研究这些现象的相关模型.
研究的目的:
- 为了研究在气压力下成熟的气模型的吸附诱导行为.
- 量化矩阵膨胀和内部变形对吸附和扩散的影响.
- 评估是否需要长时间的模拟时间来准确地确定平衡.
主要方法:
- 一个3D连接的成熟煤化模型的分子模拟与在243K的平衡中.
- 扩展压力范围模拟 (高达210 MPa) 以捕捉粘弹性行为.
- 应用线性微孔机械模型来合理化体积膨胀.
主要成果:
- 煤模型表现出粘性弹性,需要数百纳秒才能准确地进行平衡模拟.
- 忽视矩阵变形和胀导致对负荷的低估高达28%.
- 在210MPa时,矩阵体积增加了8%左右,毛孔体积和表面积增加了33%左右.
结论:
- 吸附诱导的矩阵变形对于精确建模微孔碳中的液体吸附至关重要.
- 素模型显示了压力下显著的胀和孔隙结构变化.
- 随着自由体积的增加,自我扩散率线性下降,忽视变形会低估扩散.
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