SESSION 4: TOWARDS LONGER LENGTH SCALES

Multiscale Study of the MOF/Polymer Interface

Institut Charles Gerhardt Montpellier/Université de Montpellier, Montpellier, France

MOF/polymer Mixed Matrix Membranes (MMMs) have attracted great interest in the last few years as a promising alternative to the polymer membranes currently used for gas separation processes.^[1] Although many experimental studies have focused on the elaboration and efficacy of such MMMs for specific gas separations, both the interfacial structure of these composites and the molecular mechanism of the separation phenomena are far from being understood. In this contribution, we first present a computational methodology to model the microscopic structural features of MOF/polymer interfaces.^[2] Within our framework, the MOF surface and the polymer are modelled separately at the atomistic level and then combined through a series of molecular dynamics simulations to guarantee the local relaxation of the polymer structure in the presence of the chemical environments that constitute the MOF surface. We further investigate the full extent of the interfacial polymer by extending our analysis to longer time and length scales using a mesoscopic model,^[3] based on a coarse grained MOF model recently proposed by Dürholt et al.^[4](see Figure 1). By comparing our results with experimental findings and rationalizing them we have determined the key MOF and polymer characteristics that determine their compatibility within the binary composite.^[5] Finally, we present some applications of our methodology to the study of complex phenomena such as the CO₂ adsorption at the interface of the composites^[6] and the polymer infiltration into the open pores at the MOF surface.^[7]

Figure 1: Summarized workflow of our multiscale study of a MOF/Polymer interface

[1] B. Seoane, J. Coronas, I. Gascón, M. E. Benavides, O. Karvan, J. Caro, F. Kapteijn, J. Gascón, Chem. Soc. Rev. 44, 2421, 2015
[2] R. Semino,N. Ramsahye,A. Ghoufi,G. Maurin, ACS Appl. Mater. Interfaces 8, 809, 2016
[3] R. Semino, J. P. Dürholt, R. Schmid, G. Maurin,J. Phys. Chem. C 121, 21491, 2017
[4] J. P. Dürholt, R. Galvelis, R. Schmid, Dalton Trans. 45, 4370, 2016
[5] R. Semino, J. C. Moreton, N. A. Ramsahye, S. M. Cohen, G. Maurin, Chem. Sci. 9, 315, 2018
[6] S. Hwang, R. Semino, B. Seoane, M. Zahan, C. Chmelik, R. Valiullin, M. Bertmer, J. Haase, F. Kapteijn, J. Gascon, G. Maurin, J. Kärger, Angew. Chem. Int. Ed. 57, 5156, 2018
[7] P. Duan, J. C. Moreton, S. R. Tavares, R.Semino, G. Maurin, S. M. Cohen, K. Schmidt-Rohr, submitted