Neat Pebax Research Articles

Preparation and characterization of (Pebax 1657 + silica nanoparticle)/PVC mixed matrix composite membrane for CO2/N2 separation

In this work, the films of poly(ether-block-amide) (Pebax 1657) and hydrophilic/hydrophobic silica nanoparticles (0–10 wt%) were coated on a poly(vinyl chloride) (PVC) ultrafiltration membrane to form new mixed matrix composite membranes (MMCMs) for CO2/N2 separation. The membranes were characterized by SEM, FTIR, DSC and XRD. Successful formation of a non-porous defect-free dense top layer with ~4 μm of thickness and also uniform dispersion of silica nanoparticles up to 8 wt% loading in Pebax matrix were confirmed by SEM images. The gas permeation results showed an increase in the permeance of all gases and an increase in ideal CO2/N2 selectivity with the increase in silica nanoparticle contents. Comparison between the incorporation of hydrophilic and hydrophobic silica nanoparticle into Pebax matrix revealed that the great enhancement of CO2 solubility is the key factor for the performance improvement of Pebax + silica nanoparticle membranes. The best separation performance of the hydrophilic silica nanoparticle-incorporated Pebax/PVC membrane for pure gases (at 1 bar and 25 °C) was obtained with a CO2 permeability of 124 barrer and an ideal CO2/N2 selectivity of 76, i.e., 63 and 35% higher than those of neat Pebax membrane, respectively. The corresponding values for hydrophobic silica nanoparticle-incorporated Pebax/PVC membrane were 107 barrer for CO2 permeability and 61 for ideal CO2/N2 selectivity. Also the performances of MMCMs improved upon pressure increase (1–10 bar) owing to the shift in plasticizing effect of CO2 towards the higher pressures. In addition, an increase in permeabilities with a decrease in ideal selectivity was observed upon temperature increase (25–50 °C) due to the intensification of chain mobility.

Preparation of CO2 selective composite membranes using Pebax/CuBTC/PEG-ran-PPG ternary system

Three phase Pebax® MH 1657/PEG-ran-PPG/CuBTC (polymer/liquid/solid) was successfully deposited as a selective layer on a porous Polysulfone (PSF) support. In fact, the beneficial properties of PEG (high selectivity) with those of PPG (high permeability, amorphous) have been combined with superior properties of mixed matrix membrane (MMMs). The membranes were characterized by DSC, TGA and SEM, while CuBTC was characterized by CO2 and CH4 adsorption test. Statistically based experimental design (central composite design, CCD) was applied to analyze and optimize the effect of PEG-ran-PPG (10–50 wt%) and CuBTC (0–20 wt%) mass contents on the CO2 permeance and CO2/CH4 ideal selectivity. Based on the regression coefficients of the obtained models, the CO2 permeance was notably influenced by PEG-ran-PPG, while CuBTC has the most significant effect on the CO2/CH4 ideal selectivity. Under the optimum conditions (PEG-ran-PPG: 32.76 wt% and CuBTC: 20 wt%), nearly 620% increase in the CO2 permeance and 43% enhancement in the CO2/CH4 ideal selectivity was observed compared to the neat Pebax. The effect of pressure (3, 9 and 15 bar) on the pure and mixed gas separation performance of the composite membranes was also investigated. The high solubility of CO2 in the membranes resulted in the enhancement of CO2 permeability with increase in gas pressure.

Synthesis of a PEBAX-1074/ZnO nanocomposite membrane with improved CO2 separation performance

In this investigation, polymeric nanocomposite membranes (PNMs) were prepared via incorporating zinc oxide (ZnO) into poly (ether-block-amide) (PEBAX-1074) polymer matrix with different loadings. The neat membrane and nanocomposite membranes were prepared via solution casting and solution blending methods, respectively. The fabricated membranes were characterized by field emission scanning electron microscopy (FESEM) to survey cross-sectional morphologies and thermal gravimetric analysis (TGA) to study thermal stability. Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analyses were also employed to identify variations of the chemical bonds and crystal structure of the membranes, respectively. Permeation of pure gases, CO2, CH4 and N2 through the prepared neat and nanocomposite membranes was studied at pressures of 3–18bar and temperature of 25°C. The obtained results showed that the fabricated nanocomposite membranes exhibit better separation performance compared to the neat PEBAX membrane in terms of both permeability and selectivity. As an example, at temperature of 25°C and pressure of 3bar, CO2 permeability, ideal CO2/CH4 and CO2/N2 selectivity values for the neat PEBAX membrane are 110.67 Barrer, 11.09 and 50.08, respectively, while those values are 152.27 Barrer, 13.52 and 62.15 for PEBAX/ZnO nanocomposite membrane containing 8wt% ZnO.

Ionic liquid-modified Pebax® 1657 membrane filled by ZIF-8 particles for separation of CO2 from CH4, N2 and H2

3-Di-n-butyl-2-mthylimidazolium chloride (DnBMCl) ionic liquid (IL) was synthesized and used for modification of Pebax 1657 surface. ZIF-8 particles synthesized by different molar ratios of precursors, were introduced into the matrix of IL-Pebax 1657 for fabrication of mixed matrix membranes (MMMs) by coating method. Synthesized ZIF-8 particles were characterized using laser particle size analyzer, SEM, XRD and N2 adsorption. SEM, DSC, FTIR, 13C NMR, TGA and gas permeation tests were applied for characterization and performance evaluation of MMMs. The modification of Pebax 1657 with DnBMCl lead to formation of possible Carbon-Carbon bonds between Pebax 1657 and DnBMCl and also between ZIF-8 and DnBMCl. Pure gas permeation tests showed that the higher ideal selectivities of CO2/CH4, CO2/N2 and CO2/H2 were observed for DnBMCl-modified MMMs compared to unmodified MMMs and neat Pebax 1657 membrane. Plasticization lead to inferior CO2 separation ability of MMMs in mixed gas condition compared to pure gas test. The DnBMCl-modified Pebax 1657/ZIF-8 MMMs showed superior CO2/CH4, CO2/N2 selectivities at feed pressures of 2 and 4bar.

Synthesis of a new nanocomposite membrane (PEBAX-1074/PEG-400/TiO2) in order to separate CO2 from CH4

In the present work, effects of poly ethylene glycol (PEG) and TiO2 nanoparticles incorporation with poly (ether-block-amide) (PEBAX-1074) on CO2 and CH4 permeability values and ideal CO2/CH4 selectivity through the synthesized membranes were investigated. In order to synthesize the polymeric nanocomposite membranes (PNMs), PEG-400 was blended with PEBAX-1074 and TiO2 nanofillers were incorporated into the polymer blend with various weight fractions. To study cross-sectional morphology, crystalline structure and mechanical properties of the synthesized membranes scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and tensile analysis were utilized, respectively. Fourier transform infrared (FT-IR), was also carried out to identify formation of the chemical bonds. Permeation of pure gases, CO2 and CH4, through the prepared neat PEBAX, the blended PEBAX/PEG and the PEBAX/PEG/TiO2 nanocomposite membranes was studied at pressure of 2–10 bar and temperature of 25 °C. The obtained results showed that the synthesized nanocomposite membranes exhibit better separation performance compared to the neat and the blended membranes.

Room-temperature, one-pot process for CO2 capture membranes based on PEMA-g-PPG graft copolymer

Gas separation based on membrane technology can possibly be used to offset the greenhouse effect because of its high energy efficiency and low cost. To achieve commercialization, it is essential that the gas-separation membrane demonstrates high performance and scalability. Here, we first report the room-temperature, one-pot process for CO2 capture membranes based on the synthesis of a graft copolymer comprising of poly(ethylene-alt-maleic anhydride) (PEMA) main chains and poly(propylene glycol) (PPG) side chains. As confirmed by Fourier transform infrared (FT-IR) and nuclear magnetic resonance (1H NMR) spectroscopy, the PEMA-g-PPG synthesis was based on the complete reaction (100% conversion) of O-(2-aminopropyl)-O′-(2-methoxyethyl) polypropylene glycol (AMPPG) with PEMA in butanol (BuOH) at room temperature. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) revealed that the PEMA-g-PPG graft copolymer exists in an amorphous rubbery state with a bimodal microstructure. Without any post-treatment, the as-synthesized PEMA-g-PPG in BuOH was directly coated onto a microporous polysulfone support to form thin-film composite membranes. The membrane exhibited high selectivity (i.e. 82.6 for CO2/N2 and 26.8 for CO2/CH4) and good CO2 permeability (99.1Barrer), outperforming conventional PEBAX block copolymer membranes. CO2 uptake measurements confirmed enhanced CO2 permeation resulting from the improved solubility of CO2 in PEMA-g-PPG compared with those of neat PEMA and PEBAX. The PEMA-g-PPG membrane could be commercially feasible owing to its simple coating process, low cost, high selectivity, and scalability.

Investigation of Methane and Carbon Dioxide Gases Permeability Through PEBAX/PEG/ZnO Nanoparticle Mixed Matrix Membrane

This paper presents a new kind of mixed matrix membrane using polyethylene glycol (PEG) as organic filler. In this mix, PEG and ZnO nanoparticles (as inorganic modifier) were added to a PEBAX polymer matrix at different concentration to study their effects on the morphology, permeability and selectivity of the membrane. To characterize the chemical structure of samples FTIR and for morphological characterization, XRD and SEM were employed. The permeability of pure gases CO2 and CH4 in PEBAX, and PEBAX/PEG/ZnO with different ZnO and PEG contents were determined by the constant pressure-variable volume method. Also influences of temperature and pressure on permeation properties of these membranes were studied. The results were indicative of an increase in gas permeability and enhancement which for neat PEBAX membrane, CO2/CH4 permeability of 44.6 and 2.193 Barrer and selectivity of 20.39 were obtained. The permeability of PEBAX/PEG (40 wt.%)/ZnO (4 wt.%) membrane was enhanced to 94.49 Barrer for CO2 and 3.933 for CH4. The selectivity of PEBAX/ZnO(4 wt.%) improved to 31.58 for the CO2/CH4 gas pair.

Synthesis and characterization of poly (ether‐block‐amide) mixed matrix membranes incorporated by nanoporous ZSM‐5 particles for CO2/CH4 separation

AbstractIn this work, poly (ether‐block‐amide) (Pebax MH 1657) mixed matrix membranes (MMMs) were prepared using nanoporous ZSM‐5 as a filler. The fabricated membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimeter (DSC) analysis, thermal gravimetric analysis (TGA) and X‐ray diffraction (XRD). Effects of zeoilte loading (5, 10 and 15 wt. %), and feed pressure (1, 3 and 5 bar) on CO2/CH4 separation of MMMs were investigated using constant volume/variable pressure system. SEM analysis represents a proper morphology along with proper dispersion of ZSM‐5 particles within the polymer matrix. TGA analysis demonstrated that the thermal degradation temperature (Td) of MMMs increased by increasing the ZSM‐5 loading. The obtained experimental results showed that both permeability and CO2/CH4 selectivity enhanced by addition of zeolite compared to neat Pebax. At low concentration of zeolite (5 wt. %), the CO2 permeability increased significantly from 122.4 Barrer to 217.9 Barrer at pressure of 1 bar. MMM that incorporated by 15 wt. % of zeolite showed the best CO2/CH4 selectivity of 33.9 at pressure of 1 bar. The CO2 permeability of MMM with 5 wt. % ZSM‐5 enhanced from 217.9 to 292.4 Barrer with increase in feed pressure from 1 to 5 bar. Copyright © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.

Preparation of Poly(ether-6-block amide)/PVC Thin Film Composite Membrane for CO2 Separation: Effect of Top Layer Thickness and Operating Parameters

In this work, novel thin film composite membranes (TFCs) of poly (ether-6-block amide) (Pebax-1657) on a polyvinyl chloride (PVC) ultrafiltration membrane as support were prepared using inclined coating method for CO2 separation. Investigating the effects of top selective layer thickness formed by controlling the coating angle (15-60°) and polymer solution concentration (5-10 wt.%), and also, the effects of different operating pressure (2-10 bar) and temperature (25-50 °C) conditions were selected as challenging case study. Morphological considerations of the Pebax/PVC TFCs were evaluated by scanning electron microscopy (SEM) that revealed a defect-free thin selective layer of Pebax/PVC composite membrane. The single CO2, CH4 and N2 gases' permeance carried out using constant-volume/variable-pressure method. The results suggested that the CO2 permeance, CO2/N2 and CO2/CH4 selectivity of the membranes increase upon pressure and decrease with temperature increment. In addition, the permeations of CO2, CH4 and N2 increased respectively 16.7, 21 and 18% in Pebax/PVC TFCs compared to the neat Pebax free stand membrane.

Janus composite nanoparticle-incorporated mixed matrix membranes for CO2 separation

Silver-containing Janus nanoparticles were synthesized by adhering silver onto polydopamine nanosphere and then were embedded in Pebax® MH 1657 polymer matrix to fabricate mixed matrix membranes for CO2 capture. The Janus nanoparticle was composed of a polydopamine nanosphere (~80nm) with plenty of catechol-chelated Ag+ ions and a catechol-reduced metallic Ag nanoparticle (~20nm) epitaxially growing from the surface of the polydopamine nanosphere. The highly loaded Ag+ ions (58.41wt% of total Ag content) served as CO2 facilitated transport carriers and thereby endowed the membrane with CO2 facilitated transport ability, and meanwhile the inorganic metallic Ag nanoparticle can interfere the polymer chain packing and optimize the membrane free volume characteristics therefore affecting the diffusion behavior of gas molecules. The membrane separation performance for pure gas (CO2, CH4, and N2) and binary gas mixtures (CO2/CH4 and CO2/N2) of the Janus nanoparticle-incorporated Pebax membrane was investigated and compared with that of the polydopamine nanosphere-incorporated membrane without silver modification. An anti-tradeoff effect was achieved by incorporation of the silver-containing Janus nanoparticles. The best separation performance of the Janus-incorporated Pebax membrane for pure gas was obtained with a CO2 permeability of 150Barrer and a CO2/gas selectivity of 26.3 for CO2/CH4 and 72.5 for CO2/N2, i.e., 83%, 42% and 39% higher than those of neat Pebax membrane, respectively. The results suggested that incorporation of the Janus nanoparticles could achieve both a diffusion tuning effect and a facilitated transport effect simultaneously.

Nano composite PEBAX® membranes: Effect of zeolite X filler on CO2 permeation

A PEBAX-nano zeolite X mixed matrix membrane was fabricated and operationally characterized using single gas (CO2) permeation. X-ray diffraction (XRD) analysis was used to study the arrangement of polymer chains of mixed matrix membrane. The membranes were characterized by scanning electron microscopy (SEM) to study cross-sectional morphology. The single gas permeability were carried out for neat PEBAX and PEBAX-nano zeolite X (10 wt. %) membranes. Operating pressures varied from 6 to 14 bars. CO2 permeability for the nano-composite membrane was higher than the neat polymer membrane and increased with pressure. Adding 10 wt.% of nanozeolite X into the polymeric matrix caused CO2 permeability to increase. Both structurally and operationally characterizations revealed the defect-free structure of the nano composite membrane.

Development of Mixed Matrix Membranes Containing Zeolites for Post-combustion Carbon Capture.

Mixed matrix membranes were synthesized from poly(amide-b-ethylene oxide) (PEBAX MH1657) and zeolite 13X by a solvent casting method for CO2/N2 separation. The gas permeation properties of neat PEBAX membranes and 5, 10 and 15%(wt.) 13X loadings were determined for pure CO2 and N2 via constant volume – variable pressure method. An increase in CO2 permeability was observed with increasing loading of 13X. The greatest CO2/N2 selectivity of 47 was observed at the maximum loading. Results possibly suggest an effect on the FFV by the inclusion of the 13X.

Gas Permeation Behavior of Pebax-1657 Nanocomposite Membrane Incorporated with Multiwalled Carbon Nanotubes

Incorporation of multiwalled carbon nanotubes (MWNT) on the gas permeation properties of H2, CO2, O2, and N2 gases in poly(ether-block-amide) (Pebax-1657) membrane has been investigated. Pebax-1657 was dissolved in the ethanol−water mixture and cast on an ultraporous polyethersulfone substrate followed by complete solvent evaporation. Nanocomposite membranes were prepared by dispersion of MWNT in concentrations of 0−5% of polymer weight in the Pebax solutions with sonication for 2 h to ensure uniformity. Cross-linking was carried out in hexane medium using 2,4-toluylene diisocyanate (TDI). The permeabilities of pure gases were measured at room temperature, and the ideal selectivities were determined at pressures varying from 1−3 MPa using an indigenously built high-pressure gas separation manifold. For neat Pebax membrane, high permeabilities of 55.8 and 32.1 barrers were observed for CO2 and H2 gases, respectively, whereas that of N2 was as low as 1.4 barrers. The selectivity of cross-linked 2% MWNT Peba...