High performance mixed matrix membranes (MMMs) composed of ZIF-94 filler and 6FDA-DAM polymer

Abstract

A R T I C L E I N F O Keywords:Metal organic frameworks ZIF-94 Mixed matrix membrane CO 2 capture A B S T R A C T Carbon capture and storage (CCS) using membranes for the separation of CO 2 holds great promise for the reduction of atmospheric CO 2 emissions from fuel combustion and industrial processes. Among the different process outlines, post-combustion CO 2 capture could be easily implemented in existing power plants. However, for this technology to become viable, new membrane materials have to be developed. In this article we present the development of high performance mixed matrix membranes (MMMs) composed of ZIF-94 filler and 6FDA-DAM polymer matrix. The CO 2 /N 2 separation performance was evaluated by mixed gas tests (15CO 2 :85N 2 ) at 25°C and 1-4 bar transmembrane pressure difference. The CO 2 membrane permeability was increased by the addition of the ZIF-94 particles, maintaining a constant CO 2 /N 2 selectivity of~22. The largest increase in CO 2 permeability of~200% was observed for 40 wt% ZIF-94 loading, reaching the highest permeability (2310 Barrer) at similar selectivity among 6FDA-DAM MMMs reported in literature. For the first time, the ZIF-94 metal organic framework crystals with particle size smaller than 500 nm were synthesized using nonhazardous solvent (tetrahydrofuran and methanol) instead of dimethylformamide (DMF) in a scalable process. Membranes were characterized by three non-invasive image techniques, i.e. SEM, AFM and nanoscale infrared imaging by scattering-type scanning near-field optical microscopy (s-SNOM). The combination of these techniques demonstrates a very good dispersion and interaction of the filler in the polymer layer, even at very high loadings.

Formation of a defect‐free polyimide/zeolitic imidazolate framework‐8 composite membrane for gas separation: in‐depth analysis of organic–inorganic compatibility

“…5 In another work, a good dispersion of ZIF-94 in 6FDA-DAM polyimide matrix was achieved by Etxeberria-Benavides and coworkers at the high filler loading of 40 wt%. 6 In fact, the ZIF-94/6FDA-DAM composite membrane attained 200% increment of CO 2 permeability without jeopardizing the CO 2 /N 2 selectivity. 6 Among the various fillers such as zeolite, 5,7,8 silica, [9][10][11] carbon nanotube, [12][13][14] graphene oxide [15][16][17][18] and metal organic framework (MOF), 6,[19][20][21][22][23] zeolitic imidazolate framework-8 (ZIF-8) has attracted considerable attention due to its inherently better compatibility with polymers 2 and its aperture size of 3.4 Å, 24,25 which is suitable for CO 2 separation.…”

“…In another work, a good dispersion of ZIF‐94 in 6FDA‐DAM polyimide matrix was achieved by Etxeberria‐Benavides and coworkers at the high filler loading of 40 wt% . In fact, the ZIF‐94/6FDA‐DAM composite membrane attained 200% increment of CO 2 permeability without jeopardizing the CO 2 /N 2 selectivity …”

“…In the absence of interfacial defects, 80% higher CO 2 permeability and 172% higher CO 2 /CH 4 selectivity were observed for the 1 wt% zeolite T/6FDA‐durene composite membrane as compared to the pristine 6FDA‐durene membrane . In another work, a good dispersion of ZIF‐94 in 6FDA‐DAM polyimide matrix was achieved by Etxeberria‐Benavides and coworkers at the high filler loading of 40 wt% . In fact, the ZIF‐94/6FDA‐DAM composite membrane attained 200% increment of CO 2 permeability without jeopardizing the CO 2 /N 2 selectivity …”

“…Among the various fillers such as zeolite, silica, carbon nanotube, graphene oxide and metal organic framework (MOF), zeolitic imidazolate framework‐8 (ZIF‐8) has attracted considerable attention due to its inherently better compatibility with polymers and its aperture size of 3.4 Å, which is suitable for CO 2 separation. In general, the compatibility between ZIF‐8 and polymer is enhanced mainly by introducing a linker between them.…”

Towards High Performance Metal–Organic Framework–Microporous Polymer Mixed Matrix Membranes: Addressing Compatibility and Limiting Aging by Polymer Doping

“…To demonstrate the scope of our approach, we prepareda dditional membranes using ZIF-94(Zn) as filler,i nv irtue of its high CO 2 uptake at low pressure ( Figure S5). [26] However,u pon loading 25 wt. %Z IF-94(Zn) into PIM-1, very brittle membranes were obtained with no separation selectivity.A sa nticipated, a more selectiveZ IF-94(Zn)/PIMATm embrane was formed with the assistance of Matrimid threading (Figure 3a).…”