Toward an Understanding of the Microstructure and Interfacial Properties of PIMs/ZIF-8 Mixed Matrix Membranes.
A study integrating advanced experimental and modeling tools was undertaken to characterize the microstructural and interfacial properties of mixed matrix membranes (MMMs) composed of the zeolitic imidazolate framework ZIF-8 nanoparticles (NPs) and two polymers of intrinsic microporosity (PIM-1 and PIM-EA-TB). Analysis probed both the initial ZIF-8/PIM-1 colloidal suspensions and the final hybrid membranes. By combination of dynamic light scattering (DLS) and transmission electron microscopy (TEM) analytical and imaging techniques with small-angle X-ray scattering (SAXS), the colloidal suspensions were shown to consist mainly of two distinct kinds of particles, namely, polymer aggregates of about 200 nm in diameter and densely packed ZIF-8-NP aggregates of a few 100 nm in diameter with a 3 nm thick polymer top-layer. Such aggregates are likely to impart the granular texture of ZIF-8/PIMs MMMs as shown by SEM-XEDS analysis. At the molecular scale, modeling studies showed that the surface coverage of ZIF-8 NPs by both polymers appears not to be optimal with the presence of microvoids at the interfaces that indicates only a moderate compatibility between the polymer and ZIF-8. This study shows that the microstructure of MMMs results from a complex interplay between the ZIF-8/PIM compatibility, solvent, surface chemistry of the ZIF-8 NPs, and the physicochemical properties of the polymers such as molecular structure and rigidity.
Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles St Quentin en Yvelines, Université Paris Saclay, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France.
Marvin
M
Benzaqui
Institut Charles Gerhardt Montpellier, UMR 5253 CNRS, Université de Montpellier, Place E. Bataillon, 34095 Montpellier Cedex 05, France.
Rocio
R
Semino
Institut de Minéralogie de Physique des Matériaux et de Cosmochimie, UMR 7590 CNRS UPMC, Université Paris 06 MNHN IRD, Sorbonne Universités, 4 Place Jussieu, 75252 Paris Cedex 05, France.
Nicolas
N
Menguy
Laboratoire Matière et Systèmes Complexes (MSC), UMR CNRS 7057, Université Paris Diderot, Bât. Condorcet, 10 Rue A. Domon et L. Duquet, 75013 Paris, France.
Florent
F
Carn
Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles St Quentin en Yvelines, Université Paris Saclay, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France.
Tanay
T
Kundu
Institut de Minéralogie de Physique des Matériaux et de Cosmochimie, UMR 7590 CNRS UPMC, Université Paris 06 MNHN IRD, Sorbonne Universités, 4 Place Jussieu, 75252 Paris Cedex 05, France.
Jean-Michel
JM
Guigner
EastChem School of Chemistry, University of Edinburgh , Joseph Black Building, David Brewster Road, Edinburgh EH9 3JF, U.K.
Neil B
NB
McKeown
EastChem School of Chemistry, University of Edinburgh , Joseph Black Building, David Brewster Road, Edinburgh EH9 3JF, U.K.
Kadhum J
KJ
Msayib
EastChem School of Chemistry, University of Edinburgh , Joseph Black Building, David Brewster Road, Edinburgh EH9 3JF, U.K.
Mariolino
M
Carta
EastChem School of Chemistry, University of Edinburgh , Joseph Black Building, David Brewster Road, Edinburgh EH9 3JF, U.K.
Richard
R
Malpass-Evans
Laboratoire Catalyse et Spectrochimie, Université de Caen Basse-Normandie, ENSICAEN, UNICAEN, CNRS, 14000 Caen, France.
Clément
C
Le Guillouzer
Laboratoire Catalyse et Spectrochimie, Université de Caen Basse-Normandie, ENSICAEN, UNICAEN, CNRS, 14000 Caen, France.
Guillaume
G
Clet
Institut Charles Gerhardt Montpellier, UMR 5253 CNRS, Université de Montpellier, Place E. Bataillon, 34095 Montpellier Cedex 05, France.
Naseem A
NA
Ramsahye
Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles St Quentin en Yvelines, Université Paris Saclay, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France.
Christian
C
Serre
Institut Charles Gerhardt Montpellier, UMR 5253 CNRS, Université de Montpellier, Place E. Bataillon, 34095 Montpellier Cedex 05, France.
Guillaume
G
Maurin
Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles St Quentin en Yvelines, Université Paris Saclay, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France.
Nathalie
N
Steunou
MOF/polymer interface; ZIF-8; mixed matrix membrane; molecular modeling; polymer of intrinsic microporosity; transmission electron microscopy