基于Zn4O的MOF中的水敏感性取决于结构和历史
Ping Guo1, Dhanadeep Dutta, Antek G Wong-Foy
1Department of Chemistry, University of Michigan , 930 N. University, Ann Arbor, Michigan 48109-1055, United States.
Journal of the American Chemical Society
|February 3, 2015
概括
金属有机框架 (MOFs) 显示出对水分的惊人稳定性,在降解发生之前有一个初始的诱导期. 这项研究揭示了水引起的结构崩期间MOF毛孔大小的演变.
科学领域:
- 材料科学 材料科学 材料科学
- 化学 化学 化学
- 纳米技术 纳米技术
背景情况:
- 潮湿会导致金属有机框架 (MOF) 的不可逆转的结构崩,减少其内部表面积和孔径.
- 在MOF被水分降解的过程中,精确的机制和毛孔大小的演变并未被充分理解,这是由于in situ孔隙性探测的局限性.
研究的目的:
- 为了研究MOFs在暴露于水分下的动态孔径演变和降解机制.
- 确定影响MOF稳定性和降解动力学的因素.
主要方法:
- 使用流通系统结合现场灭寿命光谱 (PALS) 来动态监测MOF孔隙.
- 使用粉末X射线衍射 (PXRD) 和现场气体吸附测量进行进一步验证.
主要成果:
- 在一些基于Zn4O的MOF中观察到水降解的意想不到的诱导期,这表明其稳定性比以前假设的更大.
- 在非功能化的MOF中表现出一个西格形降解趋势,与孔大小演变有关.
- 与MOF-5相比,IRMOF-3的降解相对湿度较低,IRMOF-3的剩余多孔性仍然存在.
- 诱导期的历史依赖于先前的水暴露.
结论:
- 这项研究揭示了某些MOF对水分的前所未有的稳定性,其特点是最初的诱导期.
- 在现场PALS提供了关键的见解,了解在潮湿诱导的降解过程中MOF多孔性的时间演变.
- 了解MOF降解机制,包括历史依赖性和西格形行为,对于它们在潮湿环境中的应用至关重要.
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