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Comprehensive structural/molecular simulations have been undertaken to study the poly(benzimidazoles) (PBI) membrane combined with four different nano-oxide materials (ZnO, Al 2 O 3 , SiO 2 and TiO 2 ) for purification and production of hydrogen from natural gases. Composite membranes were built with different amounts of nano-oxide materials to investigate the influence of nano-oxide content on the PBI membrane performance. Several structural characterizations such as FFV, WAXD and also a thermal one (glass transition temperature) were done to study the structural properties of all simulated membrane cells. Moreover, MSD and adsorption isotherms tasks were used to estimate the diffusivity and solubility of hydrogen molecules through the latter mixed matrix membranes (MMMs), respectively. Permeability and permselectivity of H 2 penetrate molecules were also carefully calculated using the aforementioned penetrating factors (diffusivity and solubility). Results show a significant improvement in structural and transport properties by increasing the nanomaterials content, which could be due to the growth of penetration pathways through the membranes. Furthermore, membranes with SiO 2 yield the best results compared to other three nano-oxide fillers. H 2 gas yields the best results that help the storage and separation of this precious gas from other gas molecules, which present in natural gases. Compared to the previous studies and literature results, the current results are accurate and reliable to describe the structural and transport properties of PBI/nano-oxides composites. [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]