Mixed matrix membranes based on UiO-66 MOFs in the polymer of intrinsic microporosity PIM-1

• Published in: Separation and purification technology Vol. 173; pp. 304 - 313
• Main Authors: Khdhayyer, Muhanned R., Esposito, Elisa, Fuoco, Alessio, Monteleone, Marcello, Giorno, Lidietta, Jansen, Johannes C., Attfield, Martin P., Budd, Peter M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2017
• Subjects: Carbon dioxide; Gas transport; Mathematical models; Maxwell model; Membranes; Metal-organic frameworks; Microporosity; Mixed matrix membranes; MOFs; Permeability; PIM-1; Separation; UiO-66; PIM-1; Gas transport; UiO-66; MOFs; Maxwell model; Mixed matrix membranes
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2016.09.036

•Metal Organic Frameworks UiO-66 improve the performance of PIM-1 gas separation membranes.•The separation performance of the MMMs exceeds the 2008 Robeson upper bound for various gas pairs.•The effect of UiO-66 on PIM-1 can be described by the Maxwell model.•Methanol treatment greatly enhances the permeability.•Mixed gas permeation experiments confirm an excellent separation performance. This work presents a study of the gas transport properties for a novel class of mixed matrix membranes (MMMs) based on the polymer of intrinsic microporosity PIM-1 loaded with UiO-66 [Zr6O4(OH)4(O2CC6H4CO2)6] based metal-organic frameworks (MOFs). Three isoreticular MOFs were dispersed in the polymer matrix, standard UiO-66, UiO-66-NH2 (functionalized with an amino group) and UiO-66-(COOH)2 (functionalized with two carboxylic groups), in order to investigate the effect of the functionalization of the linker on the gas transport. The pure gas permeabilities of He, H2, O2, N2, CH4, CO2 were studied, for the as prepared membranes and after methanol treatment, focusing attention on the potential use of these membranes for CO2/CH4 separation. The pure gas transport of the MMMs was described on the basis of the Maxwell model. The predictions of the model are discussed and compared with the experimental permeability and selectivity of the MMMs and neat PIM-1. Mixed gas permeation tests were performed on a representative sample to investigate the actual separation performance with industrially relevant gas mixtures. These confirmed the good perspectives of these MMMs in applications like CO2 removal from biogas or from flue gas.