ZIF‐based water‐stable mixed‐matrix membranes for effective CO₂ separation from humid flue gas

Abstract

Water stable mixed‐matrix membranes (MMMs) were developed to help control global warming by capturing and sequestrating carbon dioxide (CO2) from humid flue gas originated from burning of fossil fuels. MMMs of different compositions were prepared by doping glassy polymer Ultrason® S 6010 (US) with nanocrystals of zeolitic imidazolate frameworks (ZIF‐302) in varying degrees. A solution‐casting technique was used to fabricate various MMMs to optimize their CO2 capturing performance from both dry and wet gases. The prepared composite membranes indicated enhanced filler‐polymer interfacial adhesion, consistent distribution of nanofiller, and thermally stable matrix configuration. CO2 permeability of the membranes was enhanced as demonstrated by gas sorption and single gas permeation tests carried out under dry and moist circumstances. As compared to neat Ultrason® membrane, CO2 permeability and expected CO2/N2 permselectivity of the mixed membrane doped with 40 g/g ZIF‐302 nanocrystals were significantly enhanced. In contrast to the majority of previously reported membranes, key features of fabricated MMMs include their structural stability under humid conditions coupled with better and unaffected gas separation performance.

Strategies for Improving the Functionality of Zeolitic Imidazolate Frameworks: Tailoring Nanoarchitectures for Functional Applications

“…However, despite these advantages, occasionally some clusters of ZIF particles can be seen within the polymeric matrix which may lead to a slight reduction in the separation performance. To solve this issue, many recent studies have implemented a secondary carbon‐based additive or filler into the polymeric matrix such as graphene oxide and CNTs, which can greatly enhance the dispersion of ZIF‐8 particles throughout the polymeric matrix, leading to better gas or liquid mixture separation . It is expected that this emerging technique will be further developed in the future to optimize the potential of ZIF‐based MMMs.…”

Mixed Dimensional Nanostructure (UiO‐66‐Decorated MWCNT) as a Nanofiller in Mixed‐Matrix Membranes for Enhanced CO2/CH4 Separation

“…The exploitation of nonselective nanomaterials generally increases the free volume and inter‐molecular spacing in MMMs that can improve permeability of gas but not selectivity. Conversely, the MMMs exhibit improved CO 2 permeability along with selectivity of CO 2 /N 2 and CO 2 /CH 4, when selective materials with great adsorption affinity such as zeolitic imidazolate frameworks (ZIFs; 8, 301, 302), [52,59–61] and MOFs [MIL‐53(Al)‐APTES, NH 2 ‐MIL‐125, MIL‐68(Al)], [50,62–65] were used. Generally, the carbon‐based materials particularly GO are believed amongst the best fillers in MMMs for CO 2 separation owing to their better gas transport and mechanical properties [52] .…”

Carbon Capture From Flue Gas and the Atmosphere: A Perspective

“…Hybrid membrane, or mixed matrix membrane (MMM), which normally consists of an inorganic component such as zeolites, carbon nanotubes, silicates, alumina, or MOFs incorporated into the polymer matrix in the nanoparticles form (Vinoba et al, 2017;Ahmad et al, 2018;Sarfraz and Ba-Shammakh, 2018;Dilshad et al, 2019;Julian et al, 2019), is becoming a new trend to improve polymeric membranes' properties, as it could possess both advantages of inorganic and organic materials. Incorporating inorganic particles improves both the mechanical and thermal properties, making the polymeric membranes more stable.…”