Issue 47, 2023

Identifying pathways to metal–organic framework collapse during solvent activation with molecular simulations

Abstract

Metal–organic framework (MOF) materials are a vast family of nanoporous solids with potential applications ranging from drug delivery to environmental remediation. Application of MOFs in these scenarios is hindered, however, by difficulties in MOF ‘activation’ after initial synthesis – removal of the synthesis solvent from the pores to make the pore space accessible – often leading to framework collapse if improperly performed. While experimental studies have correlated collapse to specific solvent properties and conditions, the mechanism of activation-collapse is currently unknown. Developing this understanding would enable researchers to create better activation protocols for MOFs, accelerating discovery and process intensification. To achieve this goal, we simulated solvent removal using grand-canonical Monte Carlo and free energy perturbation methods. By framing activation as a fluid desorption problem, we investigated activation processes in the isoreticular metal organic framework (IRMOF) family of MOFs for different solvents. We identified two pathways for solvent activation – the solvent either desorbs uniformly from each individual pore or forms coexisting phases during desorption. These mesophases in turn lead to large capillary stresses within the framework, corroborating experimental hypotheses for the cause of activation-collapse. Finally, we found that the activation energy of solvent removal increased with pore size and connectivity due to the increased stability of solvent mesophases, matching experimental findings. Using these simulations, it is possible to screen MOF activation procedures, enabling rapid identification of ideal solvents and conditions and thus enabling faster development of MOFs for practical applications.

Graphical abstract: Identifying pathways to metal–organic framework collapse during solvent activation with molecular simulations

Supplementary files

Article information

Article type
Paper
Submitted
04 aug 2023
Accepted
09 nov 2023
First published
09 nov 2023
This article is Open Access
Creative Commons BY license

J. Mater. Chem. A, 2023,11, 25929-25937

Identifying pathways to metal–organic framework collapse during solvent activation with molecular simulations

J. R. H. Manning, G. Donval, M. Tolladay, T. L. Underwood, S. C. Parker and T. Düren, J. Mater. Chem. A, 2023, 11, 25929 DOI: 10.1039/D3TA04647H

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements