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arXiv 1209.6378cond-mat.mtrl-sciphysics.chem-ph
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柔性金属有机框架的各向异性弹性性质:多孔晶体有多软?

Anisotropic Elastic Properties of Flexible Metal-Organic Frameworks: How Soft are Soft Porous Crystals?

Aurélie U. Ortiz, Anne Boutin, Alain H. Fuchs, François-Xavier Coudert

摘要:

我们进行了从头计算的弹性常数的五个灵活的金属有机框架:MIL-53(铝),MIL-53(镓),MIL-47和正方形和菱形结构的DMOF-1。张量分析的弹性常数揭示了一个高度各向异性的弹性行为,一些变形方向表现出非常低的杨氏模量和剪切模量。这种各向异性可以在最刚性和最弱方向之间达到400:1的比率,与诸如M0 F-5和ZIF-8的非柔性M0 F的情况形成鲜明对比。此外,我们发现,灵活的MOFs可以显示非常大的负线性压缩性(NLC)。这些结果揭示了刺激诱导的结构转变的柔性MOFs的微观根源,通过连接材料的局部弹性行为和它的多稳定性。

英文摘要:

We performed ab initio calculations of the elastic constants of five flexible metal-organic frameworks: MIL-53(Al), MIL-53(Ga), MIL-47 and the square and lozenge structures of DMOF-1. Tensorial analysis of the elastic constants reveal a highly anisotropic elastic behavior, some deformation directions exhibiting very low Young's modulus and shear modulus. This anisotropy can reach a 400:1 ratio between the most rigid and weakest directions, in stark contrast with the case of non-flexible MOFs such as MOF-5 and ZIF-8. In addition, we show that flexible MOFs can display extremely large negative linear compressibility (NLC). These results uncover the microscopic roots of stimuli-induced structural transitions in flexible MOFs, by linking the local elastic behavior of the material and its multistability.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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