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Molecular simulation has been undertaken to study the structural and transport properties of Poly (amide-6-b-ethylene oxide) (PEBA 1657)/Faujasite (FAU) mixed matrix membranes. Membranes were built with different amounts of FAU nanomaterials to investigate the influence of nanomaterial content on the membrane performances. Structural characterizations such as ractional free volume (FFV), radial distribution function (RDF), wide angle XRD (WAXD) and glass transition temperature were done on the simulated membrane cells to study their structural properties. Also, by using MSD and adsorption isotherms, diffusivity and selectivity of these membranes were measured, respectively. The two main transport factors (permeability and permselectivity) were examined using calculated diffusivity and solubility, and the membrane properties were investigated at two different operating temperatures (298 K, 318 K). Results show that by increasing the nanomaterials content, structural properties improve and transport properties increase which is due to the increase of the pathways for penetrant molecules to move through the membranes. Compared to the published results, the current simulation study is more accurate in describing the structural and transport properties of PEBA/FAU mixed matrix membranes. It was found that increasing the FAU content from 0 to 20 wt% increased the permeability of the membrane to CO 2 , as well as the permselectivity for CO 2 /NO 2 from 69.4 barrer to 89.23 barrer at 298 K. This change in FAU content also decreased the glass transition temperature from 212 K to 204.1 K. [ABSTRACT FROM AUTHOR]

In this study, structural and transport mechanism and properties of two kinds of polyether block amide (PEBA 1657, PEBA 2533) membrane in presence of POSS-PEG functionalized nanoparticles were investigated by molecular dynamic simulation (MD). Monte Carlo technique was used to investigate transport properties of the simulated membranes. The wide-angle XRD (WAXD), mean square displacement (MSD), glass transition temperature (Tg) and sorption isotherm were studied to investigate the aforementioned mixed matrix membranes. Also, solubility, diffusivity, permeability and permselectivity of light gases (N2, CO2, CH4, O2, and H2) were investigated carefully by Materials Studio simulator. The results showed higher permeability for membranes with PEBA 2533 rather than the ones with PEBA 1657; this conclusion is also confirmed with the experimental results which are reported in the literature. But, for the permselectivity of membranes, the results were opposite of the permeability results. Tg for all membranes decreased by increasing the POSS-PEG nanoparticle content. Additionally, by comparing the results of the simulations with the results of literature, it is revealed that simulation results were in acceptable agreement by experiment results. [ABSTRACT FROM AUTHOR]

Molecular dynamics (MD) and Monte Carlo (MC) simulations have been used to study the PEBA 1074-PEG 400 blended membranes. By blending the membranes and TiO 2 nanomaterials, separation of CO 2 gas from CH 4 (which represents the natural gas) has been investigated. Structural analysis including WAXD, XRD, FFV and glass transition temperature has been studied to check thermal and structural properties of total simulated membranes. In addition, the adsorption and MSD isotherms have been used to measure solubility and diffusivity through these mixed matrix membranes (MMMs), respectively. Finally, based on the solubility and diffusivity coefficients, permselectivity and permeability of these gas molecules were measured. By increasing the PEG 400 and nanomaterials content, remarkable advance was observed in the transport properties of membranes, i.e. membranes permeability after addition of 40 wt% of PEG 400 and 8 wt% of TiO 2 became 47 barrer and 143 barrer, respectively. Also, the PEBA 1074/40 wt% PEG/8 wt% TiO 2 composite was selected as the optimum membrane in this study. Unlabelled Image • The molecular dynamics and Grand Canonical Monte Carlo study have been used for the PEBA 1074-PEG 400,TiO 2 membranes. • CO 2 separation from CH 4 using the PEBA 1074-PEG 400, TiO 2 membranes has been studied. • FFV, XRD, WAXD and glass transition temperature analyzes have been done. [ABSTRACT FROM AUTHOR]