PEBA Membrane Research Articles

Fluorinated MIL-53(Al) with breathing effect incorporated mixed matrix membranes for enhanced butanol/water pervaporation performance

Fillers of mixed matrix membranes (MMMs) play a crucial role in the pervaporation (PV) separation process. MIL-53(Al) is widely used in the preparation of MMMs due to its high stability, variable pore size, and ease of modification. In this study, fluorinated MIL-53(Al) (4F-MIL-53) was successfully synthesized using a solvent-free method. The introduction of fluorinated group made 4F-MIL-53 have better affinity for butanol and stronger hydrophobicity than MIL-53. Meanwhile, by utilizing its breathing effect, 4F-MIL-53 with narrow pore (4F-MIL-53(np)) could be transformed to 4F-MIL-53 with large pore (4F-MIL-53(lp)) through heat treatment. Also, the flexible framework of 4F-MIL-53 had good affinity with polymer chains. Then, 4F-MIL-53(lp) was introduced into PEBA to prepare MMMs for separating n-butanol/water. Compared with pristine PEBA membrane, the permeation flux and separation factor of the 4F-MIL-53(lp)-20/PEBA MMMs increased by 100.5 % and 90.4 %, respectively. Theoretical calculations indicated that there were multiple intermolecular forces between 4F-MIL-53(lp) and n-butanol, which enhanced the mixed matrix membrane affinity for n-butanol. The calculated self-diffusion coefficient of water in 4F-MIL-53 (lp) was lower than that in MIL-53, indicating that the introduction of fluorinated groups enhanced the hydrophobicity of MMMs. The proposed selection and modification strategies of MOF fillers provide excellent guidance for getting MMMs with high performance.

Gas transport properties of poly(ether-b-amide) segmented copolymers: The role of the degree of microphase separation in amorphous regions

Polyether-based crystalline multiblock copolymers have been employed as membrane materials for the removal of CO2 from light gases due to their excellent gas permeability and selectivity. However, the influence of the nature of the crystalline and amorphous regions on gas permeability needs to be deeply explored. In this work, the effect of the phase structure, especially the degree of microphase separation (DPS) in the amorphous regions, on the gas transport properties of poly(ether-b-amide) (PEBA) segmented copolymers has been studied. It was found that the amorphous domain consists of two partially mixed phases enriched either with poly(tetramethylene oxide) (PTMO) or with polyamide 1012 (PA1012). The effect of annealing on the microphase structure in the crystalline and amorphous regions was investigated by X-ray scattering techniques. The DPS was found to be inversely correlated with the crystallinity of the hard segments. Gas permeability measurements confirmed that for PEBA membranes with lower crystallinity, weak microphase separation favors gas permeability. All these findings provide a simple method to modulate the degree of microphase separation by varying the crystallinity of the hard segments. Additionally, this work shed light on the synergistic effects of these factors on gas permeability, providing valuable guidance to enhance the performance of gas separation membranes.

Controlling Microstructure-Transport Interplay in Poly(ether-block-amide) Multiblock Copolymer Gas Separation Membranes.

In this study, we investigated the effect of morphology on the gas-transport properties of a poly(ether-block-amide) (PEBA) multiblock copolymer. We annealed the copolymer samples and varied the annealing temperature to evaluate the influence of changes in the microstructure on the gas transport properties of PEBA. In addition, we used time-resolved attenuated total reflection Fourier transform infrared spectroscopy to evaluate the diffusion coefficient of CO2 in PEBA based on the Fickian model. The effect of the annealing temperature on the microphase-separated structure of the multiblock copolymer is discussed in detail. Furthermore, the gas diffusivity was significantly affected by the purity of the soft domains. The annealed sample demonstrated a 38% increase in CO2 permeability while maintaining a high CO2/N2 permselectivity of approximately 53. The findings of this study provide valuable insight into the design and optimization of PEBA membranes for gas separation applications.

Amine-doped PEBA membrane for CO2 capture

In recent years, mixed matrix membranes (MMMs) have been used more often in separation processes due to their excellent properties. These membranes combine the advantages of two main components, the polymer continuous and the nanoparticle dispersion phases. Block copolymers such as poly(ether-block-amide, PEBA) seems to be excellent materials for the membranes synthesis. This work aims to provide an overview of membranes made of PEBA doped with two different aminocompounds of various concentrations and their effect for CO2 sorption and separation. Most samples indicated the CO2 sorption improvement compared to the pristine PEBA. It strongly depends on concentration. The most significant changes were observed at MMM doped with 2.5% TEPA or 1% HDA. Samples were tested for the separation of binary CO2/CH4 mixture and that proved the effect on separation efficiency.

Electrospun nanofibrous poly(ether-block-amide) membrane for removing biogenic amines in acidic wastewater from the yellow rice wine factory

Compared with other techniques for wastewater treatment, adsorption offers an effective, economical and ecofriendly way to reduce the content of biogenic amines. Herein, the poly(ether-block-amide) (PEBA 2533) membranes were employed as the adsorbent to remove histamine, putrescine, cadaverine and tyramine in the synthetic and real wastewater from a local yellow rice wine factory. Electrospun PEBA membranes consisting of fine nanofibers were successfully obtained without the addition of surfactant for the first time. Characteristics of the prepared membranes were evaluated by their morphology, wetting behaviors and mechanical properties. Adsorption performance of the nanofibrous membrane was investigated in comparison to the dense membrane prepared by conventional casting. The fibrous membrane exhibited much higher adsorption rate over 10 times to the dense membrane along with 1.5 times more adsorption capacity towards the amines. In addition, the as-prepared membrane showed a promising reusability in the real wastewater treatment. The good balance of its chemical stability, adsorption capacity, selectivity, removal efficiency and reusability endows the electrospun membrane with an outstanding potential to be applied in the acidic wastewater treatment for the yellow rice wine industry.

Toluene/water separation using MCM-41/ PEBA mixed matrix membrane via pervaporation process

Pervaporation (PV) process with the mixed matrix membrane (MMM) is a feasible and cost-effective alternative to conventional volatile organic compounds (VOC) removal methods. In this study, the mesoporous silicate MCM-41 was synthesized by a new and rapid sol-gel method and incorporated into the polyether-block-amide (PEBA-2533) polymer network. Prepared MMM and MCM-41 were characterized by XRD, FESEM, TEM, AFM, TGA, DSC, FTIR, contact angle, and mechanical analyses. Effect of MCM-41 calcination on the performance of MMM for toluene/water solution separation was studied using a PV setup. Experiments were conducted to determine the effects of MCM-41 loading, feed concentration, and feed temperature on total flux, component flux, separation factor, and pervaporation separation index (PSI). For a 300 ppm toluene aqueous solution at 30 °C, the separation factor, from 44.4 to 203.7 (358.7% increment), and toluene flux, from 3.9 to 10.5 g m−2 h−1 (163.8% increment), were improved by using 7.5% uncalcined MCM-41 loading. The PSI value of this sample was attained at 67290 g m−2 h−1, which was 412% higher than that of a neat PEBA membrane (13142 g m−2 h−1).

Tuning of solvent evaporation to prepare PEBA membrane with high separation performance for the pervaporation of phenol aqueous solution

Phenol is an important chemical that is widely used as a raw material in various industries. However, its high toxicity necessitates effective treatment of phenol-containing wastewater. In this study, membrane-based separation of a phenol/water solution was investigated. A simple and feasible method for tuning the solvent evaporation was developed to fabricate poly(ether-block-amide) copolymer (PEBA) membranes with enhanced separation performance. The solvent evaporation rates and temperatures of three different PEBAs were systematically regulated. PEBA1074, as a promising candidate, was studied using different characterization techniques, such as differential scanning calorimetry and scanning electron microscopy, to reveal changes in crystallinity and membrane structure under different solvent evaporation conditions. The results showed that a low solvent evaporation rate and high temperature favored the formation of a uniform membrane with an increased number of amorphous domains. A separation factor of 78 and a flux of 1.5 kg/(m2⸱h) were obtained at 80 °C for the separation of 1.5 wt% phenol/water solution. This separation performance is superior to those of previously reported PEBA membranes. This work provides a new and easy method to fabricate PEBA membranes with enhanced separation performance, which can promote the industrial application of pervaporative separation of phenol from wastewater.

2D Co-UMOFNs filled PEBA composite membranes for pervaporation of phenol solution

Two-dimensional Co ultrathin metal–organic framework nanosheets (Co-UMOFNs) were synthesized and blended into poly (ether block amide) (PEBA) to prepare composite mixed matrix membranes on PVDF supports for the pervaporation of phenol aqueous solution. The membranes were characterized by XRD, ATR-IR, TGA, CA and SEM measurements. Effects of the Co-UMOFNs loading, feed temperature and feed concentration on phenol separation performance were investigated. The results showed that Co-UMOFNs have a two-dimensional layered morphology and have good compatibility with the PEBA. A “brick and mortar” architecture morphology was achieved after incorporating Co-UMOFNs into the PEBA membrane. The amorphous PE segments in the PEBA were turned into a crystalline structure, restricting the motion of PE segments. The filling of Co-UMOFNs slightly improved the thermal stability and hydrophobicity as well. With the increase of the Co-UMOFNs loading from 0% to 40%, the phenol separation factor increased from 27 to 45, and the total flux decreased from 1.2 kg m-2h-1 to 0.42 kg m-2h-1, when separation of 1000 ppm phenol solution at 70 °C. The interlayer galleries induced by the Co-UMOFNs stacking increased the tortuosity, and the crystalline structure of the Co-UMOFNs-PEBA improved the energy barriers of water penetration. Therefore the water flux was inhibited and the phenol separation factor increased. Depression of water permeation can be another protocol to prepare high-performance organophilic pervaporation membranes.

Electrospun nanofibrous polyether-block-amide membrane containing silica nanoparticles for water desalination by vacuum membrane distillation

In this work, hydrophobic nanofibrous membranes based on polyether-block-amide (PEBAX-2533) were prepared by the electrospinning technique for using in the vacuum membrane distillation (VMD) process for water desalination applications. In the first part of this study, the influence of the electrospinning conditions like polymer concentration, surfactant concentration, applied voltage, spinneret to collector distance, feed injection rate and spinneret diameter on the morphology of the electrospun mats was investigated and optimized to obtain uniform, bead-less and defect-free nanofibrous PEBA membranes. In the second part, the electrospun nanofibrous SiO2/PEBAX-2533 membranes were fabricated by incorporating silica nanoparticles into the polymer solution. The morphology, structure, and surface properties of the prepared nanofibrous SiO2/PEBA membranes were characterized by the SEM, FTIR, OCA, and tensile strength tests. Likewise, the VMD performance of the prepared electrospun SiO2/PEBA membranes was studied for the desalination of NaCl aqueous solutions at various operating conditions. It was observed that the VMD performance of the prepared electrospun nanofibrous SiO2/PEBAX-2533 membrane containing 8 wt% of silica nanoparticles had the best separation performance in terms of the water flux, flux decline and TDS content of the permeate stream. Finally, a comparison between the prepared nanofibrous SiO2/PEBAX-2533 membrane and a commercial PVDF membrane revealed that the VMD separation performance and long-term stability of the electrospun membrane were much better than those of the commercial PVDF membrane.

The fabrication, characterization, and pervaporation performance of poly(ether-block-amide) membranes blended with 4-(trifluoromethyl)-N(pyridine-2-yl)benzamide and 4-(dimethylamino)-N(pyridine-2-yl)benzamide fillers

Hybrid separation materials intended for the hydrophobic pervaporation process with a new type of fillers were generated. Membranes based on poly(ether block amide) (Peba 2533) containing two organic fillers: 4-(trifluoromethyl)-N-(pyridine-2-yl)benzamide (denoted as F1) and 4-(dimethylamino)-N-(pyridine-2-yl)benzamide (denoted as F2) were fabricated. Novel materials were systematically characterized from the material point of view and subsequently applied in the pervaporative separation of binary water-organic mixture. The correlation between the type (e.g. hydrophobicity) and amount of the filler on the membrane performance has been discussed. Thepervaporation performance was assessed for ethanol/water mixture containing 5 wt% ethanol at temperatures ranging from 30 °C to 60 °C. The separation factor (β), thickness normalized total and partial permeate fluxes (Jt,N and Ji,N), and thickness normalized Pervaporation Separation Index (PSIN) were utilized for evaluation of the process. The best efficiency in recovery of ethanol from a mixture containing 5 wt% of ethanol was found for the membranes containing 2.5 wt% of F1 (membrane denoted as PF1-2.5) and 10 wt% of F2 (membrane denoted as PF2-10). Theincorporation of the organic fillers improved the pervaporation performance of the PEBA membrane, regarding both permeate flux andseparation factor. The highest normalized flux of 28.9 μm kg m-2h−1 and separation factor of 4.6 was achieved at 60 °C, using PF1-2.5 in contact with 5 wt% ethanol as feed.

Green extraction of perilla volatile organic compounds by pervaporation

Volatile organic compounds (VOCs) present in perilla essential oil are of high interest in medicinal and food processing. In this work, pervaporation was implemented to extract the valuable perilla VOCs from dilute aqueous solutions as a green process. Three representative VOCs of perilla (i.e., limonene, linalool, and perillaldehyde) having different functional groups were selected as model components, and poly(ether-block-amide) (PEBA) and polydimethylsiloxane (PDMS) membranes were prepared for the VOC extraction studies. The influences of operating conditions (i.e., feed concentration and temperature) on the pervaporation performance of the membranes were investigated. In binary VOC/water mixtures, an increase in the feed concentration increased the VOC flux and decreased the separation factor. The VOC flux also increased significantly with temperature, mainly due to an augmented driving force for permeation. The impact of the coupling effects in multicomponent permeation was evaluated by comparing the pervaporation performance of VOCs in binary VOC/water and quaternary VOCs/water systems. Results show that the VOC permeation behavior was affected by the presence of other VOCs, depending on the permeant–permeant and membrane–permeant interactions. Based on pervaporation separation index, the PEBA membrane showed a better overall separation efficiency than the PDMS membrane for the extraction of perilla VOCs. Since pervaporation does not involve any chemical solvents and operates at moderate temperatures, it provides a green process for extracting valuable perilla VOCs.

Comparison of different MOF fillers on CO2 removal performance of supported PEBA mixed matrix membranes

AbstractPoly(amide‐6‐b‐ethylene oxide)(PEBA) mixed matrix membranes (MMMs) containing different metal‐organic frameworks (MOFs) of CuBTC, ZIF‐8, and ZIF‐67 have been dip‐coated on asymmetric PAN supports. To optimize the ideal skin‐layer parameters, MOF loadings of 5, 15, 25, and 35 wt% were applied. The synthesized MOFs and MMMs were structurally characterized using X‐ray diffraction (XRD), Fourier‐transform infrared (FTIR), and field emission scanning electron microscopy (FESEM). The average sizes of the synthesized ZIF‐8, ZIF‐67, and CuBTC have been determined about 100, 400, and 60–500 nm, respectively. Permeability tests of the MMMs performed using 12‐bar feed streams of pure CO2, CH4, and N2, showed 200–338% enhancements of CO2 permeability and up to a 43% increase in CO2/CH4 selectivity relative to the neat PEBA membrane. The membrane performances were also examined by the mixed gas feeds of CO2:CH4 (10:90). © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.

Perstraction of phenolic compounds via nonporous PEBA membranes

This study deals with removal of phenolic compounds from water by perstraction, and poly(ether-b-amide) (PEBA) membranes were selected because of their excellent permeability to phenolics. The permeability, diffusivity and solubility of model phenolic compounds (including the simplest phenol (PhOH), 4-methylphenol (MePhOH), 4-nitrophenol (O2NPhOH) and 4-chlorophenol (ClPhOH)) in the membrane were investigated. The membrane showed a permeability in the order of ClPhOH > MePhOH > O2NPhOH > PhOH, while the diffusivity followed the order of PhOH > MePhOH > O2NPhOH > ClPhOH. Based on the resistance-in-series model, the mass transfer characteristics of the liquid/membrane/liquid perstraction system was analyzed, and the individual mass transfer resistances from the various steps of the perstraction process were estimated. It was revealed that the membrane resistance was significant, and the mass transfer resistance at the downstream side of the membrane as a result of phenol desorption from the membrane and boundary layer effects was not negligible. While the strong affinity between PEBA and phenolics was responsible for the good phenol permeability in the membrane, it also resulted in a high resistance to phenol desorption from the membrane. The use of an alkaline stripping agent can effectively enhance phenol removal from water by reducing the mass transfer resistances of the liquid boundary layers and phenol desorption at the downstream side of the membrane. For a given phenolic compound, the enhancement in mass transfer rate was affected by the alkaline concentration, and the enhancement was particularly significant when thin membranes were used.

Coordinate covalent grafted ILs-modified MIL-101/PEBA membrane for pervaporation: Adsorption simulation and separation characteristics

High porosity and large pore volume of MIL-101 MOF makes it a potential material to be used in membrane separation technology. However, the extra-large pore size and natural hydrophilicity restrict its application in the organic perm-selective pervaporation process. To overcome this issue, Herein, we successfully synthesized ILs@MOFs composite by modifying MIL-101 via coordinative covalent grafting of designed hydrophobic ionic liquids (ILs). Later on, synthesized ILs-modified MIL-101 was embedded into poly (ether-block-amide) (PEBA) polymer to fabricate mixed matrix membranes (MMMs) for ethyl acetate perm-selective pervaporation. Incorporation of ILs within the cages and over the surface of MIL-101 not only successfully tuned the pore structure and surface properties of MIL-101 but also inhibits the formation larger aggregates with no obvious defects in resultant MMMs. Moreover, molecular simulation verified that the grafted ILs endowed MIL-101 with better adsorption ability for ethyl acetate and improved interfacial compatibility with PEBA. The optimized MMMs exhibited outstanding separation performance for 5 wt% feed solution at 30 °C, with a separation factor of 207.6 and normalized total flux of 51.8 kg·μm·m−2·h−1. Compared with the pure PEBA membrane, the separation factor and ethyl acetate flux increased by 205.7% and 129.5%, respectively, while the MMMs embedding original MIL-101 showed a decrease in separation factor. This study may inspire the design and construction of high-performance MMMs by employing modification in porous nanomaterial microstructure.

CO2/CH4 mixed gas separation using poly(ether-b-amide)-ZnO nanocomposite membranes: Experimental and molecular dynamics study

Poly (ether-b-amide) (PEBA) mixed matrix membranes (MMMs) filled by different amounts of nano ZnO (up to 1 wt %) were synthesized and their gas separation performance was evaluated for CO2, CH4 and N2 pure gas and their binary mixtures. The ZnO-filled PEBA MMMs were characterized using ATR-FTIR, FESEM, AFM, TGA, DMTA, XRD and Mechanical tensile strength analyses. Generally, it was revealed that 0.5 wt % loading of ZnO into the polymer matrix caused a ZnO−PEO interaction; while ZnO–ZnO self-association hindered the interaction for the MMMs with other loadings of ZnO. As a result, PEBA-ZnO 0.5 wt % MMM possessed a higher glass transition temperature (Tg). Therefore, the CO2 permeability through PEBA-ZnO 0.5 wt % enhanced 27% than simple PEBA membrane. Moreover, all the fabricated MMMs were simulated by molecular simulation. Grand Canonical Monte Carlo (GCMC) and Molecular Dynamics (MD) methods were also applied to simulate the structural and gas transport properties of the membranes. The RDF, XRD, Tg, FFV and density analysis were compared with experimental results. Also, a binary mixture of CO2:CH4 (10:90) was used to determine CO2 permeability and CO2/CH4 selectivity, which were considerably reduced compared to single gas experiments. Moreover, the solubility of the binary gas mixture, the energy distribution and density distribution of both gases within the simulated cell were calculated by molecular simulation.

Salt transport in polymeric pervaporation membrane

Abstract The salt transport in a PEBA membrane used in pervaporative desalination was studied. The concentration profile of salt in the membrane during pervaporation was investigated experimentally using a multilayer membrane. The salt was found to be sorbed in the membrane but was not removed during the pervaporative desalination process, and the salt concentration in the membrane varied linearly with position. High purity water was obtained as the permeate as long as the permeate side was kept dry under vacuum. The accumulated salt uptake in the membrane follows the order of MgCl2 > NaCl > Na2SO4. The solubility of salt in the membrane follows the order of MgCl2 > NaCl > Na2SO4. Both the permeability and diffusivity of salt in the membrane follow the order of NaCl > MgCl2 > Na2SO4. The permeability of salt in the membrane is not influenced by the feed salt concentration. It is mainly determined by the diffusion coefficients.

Extraction of dissolved methane from aqueous solutions by membranes: Modelling and parametric studies

A parametric study was carried out for the extraction of dissolved methane from aqueous solutions using membranes. Both nonporous membranes based on rubbery polymers (e.g., polydimethylsiloxane (PDMS) and poly(ether-b-amide) (PEBA)) and hydrophobic microporous membranes (e.g., polytetrafluoroethylene (PTFE)) were evaluated. Through modelling and parametric analyses, the effects of concentration polarization in the liquid phase at the feed side on extraction of dissolved methane from aqueous solutions were evaluated. It was shown that when the concentration polarization in the liquid boundary layer was negligible, the microporous PTFE membrane outperformed the nonporous membranes in terms of methane flux (3–5 orders of magnitude higher than the nonporous membranes) and methane concentration in the wet permeate stream (~97 mol.% with the PTFE membrane). However, under normal hydrodynamic conditions, the effect of concentration polarization at the feed side was found not to be negligible, and the methane extraction flux was compromised significantly (with a flux reduction of 90% for PTFE and PDMS membranes and 50% for PEBA membrane, at a permeate pressure of 10 kPa). It was found that increasing the permeate pressure would mitigate concentration polarization at the expense of lowered flux. Proper control of the hydrodynamic conditions of feed liquid to enhance mass transfer near the membrane surface appears to be a practical approach to the degassing application.

Ionic liquid-modified MCM-41-polymer mixed matrix membrane for butanol pervaporation.

Because of the preferential butanol selectivity of some ionic liquids (ILs), an increasing amount of research has appeared regarding their application in butanol separation. In this research, two ionic liquids, namely, 1-ethyl-3-vinylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([EVIM][Tf2N], IL1) and N-octyl-pyridinium bis[(trifluoromethyl)sulfonyl]imide ([OMPY][Tf2N], IL2), were applied to modify a mesoporous molecular sieve MCM-41. The IL-modified MCM-41 samples were characterized by XPS, BET, XRD, SEM and TEM. The ionic liquid-modified MCM-41 was incorporated into the polymer PEBA to prepare mixed matrix membranes to study the influences of the filling of IL-modified MCM-41 and operating conditions on the performance of the mixed matrix membrane for butanol pervaporation. The results indicated that the pervaporation performance of the PEBA membrane was enhanced by the incorporation of IL-modified MCM-41. When the temperature of the feeding liquid was 35°C and the mass fraction of butanol was 2.5 wt%, the 5% MCM-41-IL2-PEBA membrane showed a permeation flux of 421.7 g m−2 h−1 and a separation factor of 25.4. The permeation flux and the separation factor of the membrane increased as the temperature of the feeding liquid increased. The results of the long-period experiment suggested that the 5% MCM-41-IL2-PEBA membrane exhibited high stability within 100 h of operation.

Three-component mixed matrix membrane containing [Hmim][PF6] ionic liquid and ZSM-5 nanoparticles based on poly (ether-block-amide) for the pervaporation process

Three-component mixed matrix membranes based on poly (ether-block-amide) (PEBA) were prepared by incorporation of ZSM-5 zeolite nanoparticles and [Hmim][PF6] ionic liquid for the separation of ethyl acetate (EAc) from EAc/water mixtures using the pervaporation process. At first, the dual-layer PEBA/polyethersulfone (PES) membranes containing [Hmim][PF6] in the active layer were prepared and employed in the pervaporation process. It was found that the ionic liquid leached out from the membrane during the pervaporation experiments and decreased the membrane selectivity. In order to avoid leaching out of the ionic liquid, triple-layer membranes consisting of a ZSM-5/PEBA as the top layer on a [Hmim][PF6]/PEBA as the intermediate layer and PES as the support layer were developed. The effect of ionic liquid concentration in the intermediate layer on the membrane separation performance was investigated and the results indicated that the membrane containing 2.5%wt. [Hmim][PF6] had the best separation performance in terms of the pervaporation separation index (PSI). Moreover, the ZSM-5 nanoparticles were added to the intermediate layer of the triple-layer membranes to improve the performance of the membranes. It was found that simultaneous loading of the ZSM-5 and [Hmim][PF6] in the PEBA matrix significantly improved the separation performance of the membrane as the PSI of the prepared three-component mixed matrix membrane was 1.5 times the PSI of the neat PEBA membrane.

Comparison of ZnO nanofillers of different shapes on physical, thermal and gas transport properties of PEBA membrane: experimental testing and molecular simulation

AbstractBACKGROUNDPEBA and nano‐ZnO have been discussed for membrane modification and for gas separation in different studies and in mixed matrix membranes (i.e. PEBA/TiO2, PE/ZnO); however, no report has been published on the gas transport properties of ZnO/PEBA hybrid membranes.RESULTSMolecular simulation and experimental approaches were done using PEBA 1657 mixed matrix membranes (MMMs) loaded with ZnO nanorod‐ and nanosphere shaped nanomaterials at 0.5 wt% and 1 wt% loading to investigate the gas separation properties of these MMMs. Structural characterizationwas carried out by FESEM, AFM, BET and FTIR on synthesized membranes, and FFV and WAXD on the simulated membrane cells to study their structural properties. Thermal analysis was carried out by TGA, DMTA and calculation of the glass transition temperature to investigate the thermal properties of the MMMs. The results showed that the addition of ZnO filler significantly improved both the physical and thermal properties of the MMMs based on the characterization tests. The transport properties of the MMMs for three single light gas molecules (CO2, CH4and N2) were investigated using experimental set‐up testing (permeability and selectivity), and also by molecular dynamic and Monte Carlo approaches in molecular simulation (diffusivity and solubility). The addition of ZnO nanomaterials in both shapes to the polymeric membrane significantly increased the transport properties; for example, CO2permeability increased from 120 for membrane without nanomaterial to 135 barrer for membrane with 0.5 wt% of nanosphere ZnO and 157 barrer for membrane with 0.5 wt% nanorod ZnO.CONCLUSIONThe permeability of CH4and N2gases into all samples showed no significant change with an increase in pressure or ZnO loading which is likely due to the penetration paths in the membranes. The membrane with 1 wt% ZnO nanorods had the best performance in the Robeson upper bound 2008 diagram. This sample is thus suggested for industrial development. The simulation results showed a similar trend for the membranes and gas molecules, with an error of 25% to 65% from experimental results. We conclude that the PEBA/1 wt% ZnO nanorods membrane could be an ideal solid polymer membrane for gas separation applications. © 2018 Society of Chemical Industry