Magnetic nanoFe₂O₃ – incorporated PEBA membranes for CO₂/CH₄ and CO₂/N₂ separation: experimental study and grand canonical Monte Carlo and molecular dynamics simulations

Abstract

Mixed matrix membranes (MMMs) comprised of organic selective polymers and inorganic nano‐particles under the name of fillers have attracted much attention in the field of gas separation. In this study, poly (amide‐6‐b‐ethylene oxide) [PEBA]/Fe2O3 mixed matrix membranes were prepared using the dry phase separation technique with ethanol / water (70/30 wt%) as solvent. Various amount of Fe2O3 nanoparticles were chosen to disperse within the polymer matrix (0, 0.5, 1, 1.5 and 2 wt% of polymer). To prepare this type of novel membrane, a magnetic field of 0.3 T was used to align the position of NPs. The structural properties and surface morphology of prepared membranes were characterized by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). Field emission scanning electron microscopy analysis was also used to study the physical bonding. Phase identification and crystallinity, effective area, and distribution of pore size were investigated by X‐ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) analysis. Carbon dioxide permeability through these membranes increased with pressure in the range of 2 to 14 bar. Magnetic membrane loaded with 1.5 wt% of Fe2O3 gave the best performance: CO2 permeability, CO2/CH4, and CO2/N2 selectivity were enhanced by 30, 42 and 81%, compared to a pure membrane, respectively. The results indicated that the magnetic MMMs gave better separation performance than pure membranes. Molecular simulation has also been used to investigate the structural and transport properties of fabricated membranes. Structural characterizations like radial distribution function (RDF), fractional free volume (FFV), and X‐ray diffraction were applied to the simulated membrane cells. Grand canonical Monte Carlo (GCMC) and molecular dynamic (MD) simulations, were used to calculate the selectivity and diffusivity of membranes. Results from experimental tests and simulation runs revealed that the selectivity and permeability of fabricated and simulated membranes are consistent. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

A theoretical probe into the separation of CO2/CH4/N2 mixtures with polysulfone/polydimethylsiloxane–nano zinc oxide MMM

“…Combination of significant properties of NPs with the natural features of polymers undoubtedly improves the physical and transport properties of novel MMMs 64 . In present article, the gas transport behavior of PSf polymer blended with PDMS, and loaded with ZnO NPs has been investigated It is worth pointing that, solution-diffusion is the dominant mechanism of dense membranes regarding the transport behavior and associated diffusion and solubility coefficients 56 , 65 .…”

“…( 1 ) and ( 2 ), respectively. where is the diffusivity coefficient, is the solubility coefficient and is the selectivity of gas A/B 64 , 66 , 67 . Generally, the selectivity can be defined as the permeability of one component over the other one which literally indicates the competence of each gas molecules.…”

Molecular Simulation and Computational Modeling of Gas Separation through Polycarbonate/p-Nitroaniline/Zeolite 4A Mixed Matrix Membranes

“…Both the diffusivity and solubility coefficient depend on the interactions between polymer and gas molecules, as well as gas–gas interactions. The permeability and selectivity of a membrane is calculated as follows. where D , S and α A/B are the diffusivity coefficient, solubility coefficient, and the selectivity of gas A/gas B. − …”

Influence of alternating magnetic field's frequency and exposure time on distribution of α‐Fe2O3/TiO2 fillers for gas separation membranes: Quantitative approach

“…In most studies, the static magnetic field in a single direction was applied after casting the membrane such as the vertical or horizontal direction. These studies present improvement in membrane morphology or gas separation performances 6–11 …”