Synthesis, characterization and comparative study of Zn, Fe, and Cu MOFs-impregnated polysulfone mixed-matrix membranes for CO2/N2 gas separation.

Decarbonization from fossil-combusted flue gas is crucial for recovering carbon sources and mitigating global warming risks. Composite membranes made of polysulfone (PSF) were created by doping Fe, Cu, and Zn metal-organic frameworks (MOFs). Synthesized MOF nanomaterials and membranes were characterized using advanced techniques to assess their structural, crystalline, morphological, thermal and decarbonization properties. Chemical characteristics of materials assessed through FTIR spectroscopy corroborated formation of MOFs nanocrystals. Crystalline phases of prepared MOF-based materials were established by XRD patterns. SEM-EDX micrographs indicated decent surface topography, uniform nanofiller distribution and compatible filler-matrix adhesion. Characteristic temperatures and improved thermal stability of membranes were inferred by TGA thermograms. Decarbonization efficiency of produced membranes determined by single- and mixed-gas permeation experiments using Gas Permeation rig indicated CO2 permeability improvement of about 2, 2.2 and 3.8 along with CO2/N2 permselectivity enhancement of 1.6, 1.5 and 2.1 for Cu, Zn and Fe based composite membranes, respectively.