Mouhat F, Bousquet D, Boutin A, Bouëssel du Bourg L, Coudert FX, Fuchs AH. Softening upon Adsorption in Microporous Materials: A Counterintuitive Mechanical Response.
J Phys Chem Lett 2015;
6:4265-4269. [PMID:
26538042 DOI:
10.1021/acs.jpclett.5b01965]
[Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We demonstrate here that microporous materials can exhibit softening upon adsorption of guest molecules, at low to intermediate pore loading, in parallel to the pore shrinking that is well-known in this regime. This novel and counterintuitive mechanical response was observed through molecular simulations of both model pore systems (such as slit pore) and real metal-organic frameworks. It is contrary to common belief that adsorption of guest molecules necessarily leads to stiffening due to increased density, a fact that we show is the high-loading limit of a more complex behavior: a nonmonotonic softening-then-stiffening.
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