Blend Composite Membranes Research Articles

Ce–Mn bimetallic oxide-doped SPEEK/SPPO blend composite membranes to induce high oxidative tolerance and proton conductivity for hydrogen fuel cells

Utilizing CeMnOx bimetallic oxide as fillers in SPEEK/SPPO blend polymer backbone demonstrated outstanding oxidative stability and improved performance in PEMFCs.

Development of Multiwalled Carbon Nanotube-Reinforced Biodegradable Polylactic Acid/Polybutylene Succinate Blend Membrane.

Currently, gas separation (GS) membranes are produced from petrochemical-based polymers, but their lifespan is severely impacting the environment. Therefore, there has recently been growing interest in developing ecofriendly biodegradable polymer-based GS membranes. This study developed a polylactic acid (PLA)/polybutylene succinate (PBS) blend composite membrane for GS using the dry/wet phase inversion technique. The influence of the multiwalled carbon nanotube (MWCNT) concentration in the PLA/PBS blend was studied by investigating tensile properties, porosity, percentage crystallinity, contact angle, and gas permeance.The obtained results demonstrate that the addition of MWCNT enhances the tensile strength, porosity, and percentage crystallinity, whereas it decreases the contact angle. The pure gas permeation was investigated at pressures of 2–4 bar at 25 °C. The gas permeation study revealed that the PLA/PBS blend with 0.5% wt. MWCNT enhanced the gas permeance and selectivity at 4 bar. The gas permeance acquired at 25 °C and 4 bar for PLA/PBS reinforced with MWCNT was highest in hydrogen followed by carbon dioxide, argon, and nitrogen. Additionally, a study of the membrane morphology illustrated the uniform dispersion of MWCNT in the PLA/PBS blend. The investigation concluded that membranes containing MWCNT are capable of separating gases at the molecular level, thereby reducing energy consumption.

Surface roughness of ternary blends: Polypropylene/chitosan/sisal fiber membranes

The rough morphological structure of ternary blend composite membranes was studied. The surface roughness of the composites were analysed. Recurrent topographies and the reliance of length-scale on rough surfaces were established in the analysis done by scanning probe electron microscopy. The membranes with increasing amount of sisal fibre exhibited higher roughness surface.

Improved fuel cell properties of Nano-TiO2 doped Poly(Vinylidene fluoride) and phosphonated Poly(Vinyl alcohol) composite blend membranes for PEM fuel cells

Blend composite membranes are known as a good alternative to expensive Nafion membrane since they combine the superior properties of their components in a single structure. Herein, poly(vinylidene fluoride) (PVDF) - phosphonated polyvinyl alcohol (PPVA) blend membranes (90/10 by mass) were prepared with the solution casting method. Then, nano-TiO2 were added at varying mass ratios (2, 5, 8, 10, and 15%) to improve the performance of the synthesized membranes. Characterization tests namely, Fourier Transform Infrared (FTIR), water uptake capacity, ion exchange capacity (IEC), proton conductivity, dynamic mechanic analysis, open-circuit voltage (OCV) measurements, and performance tests were conducted. PVDF/PPVA membrane containing 8% nano-TiO2 exhibited the highest performance with 382.7 mA/cm2 of current density and 225.4 mW cm−2 of power density. The OCV measurements showed 8.57% voltage decrement at the end of 1000 h. Obtained results show the high potential of TiO2 doped PVDF/PPVA membranes could be considered as a favorable candidate for fuel cells.

Improved CO2 separation performance of composite membrane with the aids of low-temperature plasma treatment

In this paper, Pebax and Pebax-Tripropionin (TPP) blend multilayer composite membranes were firstly prepared with the aids of low-temperature plasma treatment, and the CO2/N2 separation properties of the prepared composite membranes were studied. For multilayer composite membranes, PDMS gutter layer was modified with low-temperature plasma of air. The surface properties of the modified PDMS gutter layer (PDMS-plasma) were characterized by contact angle and Fourier transform infrared spectroscopy (FTIR). After treatment, the polar groups were formed on the surface of PDMS and made it hydrophilic, then a defect-free thin Pebax selective layer was successfully formed on PDMS-plasma gutter layer. The CO2 permeance and CO2/N2 selectivity of Psf/PDMS-plasma/Pebax composite membrane were 170 GPU and 49 respectively. Moreover, TPP was blended with Pebax to further enhance the CO2 permeation of the composite membranes, where TPP acted as a plasticizer and hindered the formation of hydrogen bonding in Pebax. The CO2 permeances of Psf/PDMS-plasma/Pebax-TPP blend composite membranes increased greatly with the increase of TPP content. And, the CO2 permeance of Psf/PDMS-plasma/Pebax-TPP (50 wt%) composite membrane was higher than 400 GPU, which was almost two and half times of that of composite membrane without TPP. The composite membranes prepared in this study showed good CO2/N2 separation performance.

Quaternized poly(2.6 dimethyl‐1.4 phenylene oxide)/polysulfone blend composite membrane doped with ZnO‐nanoparticles for alkaline fuel cells

ABSTRACTA series of quaternized poly(2.6 dimethyl‐1.4 phenylene oxide)/polysulfone (QPPO/PSF) blend anion exchange membrane (AEM) were successfully fabricated and characterized for alkaline fuel cell application. Zinc oxide (ZnO) nanoparticles were introduced in the polymer matrix to enhance the intrinsic properties of the AEM. To confirm successful fabrication, Fourier‐transform infrared spectroscopy and nuclear magnetic resonance (1H‐NMR) were used. The membrane properties were enhanced by the addition of ZnO nanoparticles. The addition of ZnO nanoparticles resulted to a higher ion exchange capacity (IEC) of 3.72 mmol g−1, increase of ion conductivity (IC) up to 52.34 mS cm−1 at 80 °C, enhancement of water uptake, and reduced methanol permeability. The QPPO/PSF/2% ZnO composite retained over 80% of its initial IC at room temperature and also retained over 50% of its initial IC at 80 °C when evaluated for alkaline stability. The maximum power output reached for the membrane electrode assembly constructed with QPPO/PSF/2%ZnO was 69 mW cm−2 at room temperature, which is about three times more than the parent QPPO membrane. The above results indicate that QPPO/PSF/ZnO is a good candidate as an AEM for fuel cell application. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45959.

Poly (vinyl alcohol)/carboxymethyl cellulose sodium blend composite nanofiltration membranes developed via interfacial polymerization

A novel negatively charged blend composite nanofiltration (NF) membranes were prepared via interfacial polymerization (IP), occurring between poly (vinyl alcohol) (PVA) blending with carboxymethyl cellulose sodium (CMC-Na) and 1, 6-hexamethylene diisocyanate (HDI) at ambient temperature. It was found that the increases in the total concentration of PVA and CMC-Na and the surfactant concentration could reduce the contact angles of the resultant membrane surfaces significantly, while the prolonged IP time increased the contact angle under the test conditions. The performance of the obtained PVA-CMC/PS composite membranes was tested by permeation of different inorganic electrolyte solutions with 5mM concentration. The rejections of different salts by the optimized membrane were as follows: Na2SO4 93.7%, NaCl 32.6%, MgSO4 24.5%, and MgCl2 8.6%. Obviously, the difference in the rejections to Na2SO4 and NaCl is above 60%, especially beneficial to the removal of hardness and partial desalination. In contrast to other PVA NF membranes, the blend composite NF membrane had the relatively high pure water permeability (PWP) and high permeate flux (F) while maintaining proper balance between permeate flux and salt rejection.

PEMWE를 위한 Cs치환에 따른 공유가교 SPEEK/Cs(x)-TPA/Ceria막의 합성 및 특성 연구

CL-SPEEK/Cs-TPA/CeO2 composite membrane was prepared for polymer electrolyte membrane water electrolysis (PEMWE). In order to improve the electrochemical, mechanical, durabilities and electrocatalytic characteristics, engineering plastic of polyether ether ketone (PEEK) as polymer matrix was sulfonated and the organic-inorganic blend composite membranes was prepared by loading cesium-substituted tungstophosphoric acid (Cs-TPA) by titration method with cross-linking agent contents of 0.01mL. Ceria (CeO2) was used to scavenge free radicals which attack the membrane in the PEMWE circumstance and to increase the duration of the membrane. In conclusion, CL-SPEEK/Cs(1)-TPA/Ceria 1% membrane showed the optimum results such as 0.119 S/cm at 80°C of proton conductivity and 62MPa of tensile strength.

Improving CO2 separation performance of the polyethylene glycol (PEG)/polytrifluoropropylsiloxane (PTFPMS) blend composite membrane

Polyethylene glycol (PEG) as a promoting material for CO2 separation performance of a composite membrane is introduced into the polytrifluoropropylmethylsiloxane (PTFPMS) network to form a blend selective layer coated on a porous polyetherimide (PEI) support membrane. The maximum blend ratio of PEG to PTFMS in mass is determined for PEG-400, PEG-600, and PEG-1000 at 0.5, 0.2 and 0.2 from the blend solution status observed by an optical microscope. The miscibility of PEG and PTFPMS is verified from one peak of the blend film in DSC characterization. Furthermore, the interaction between PEG and PTFPMS is van der Waals force from the decreasing strength of ether group in ATR-FTIR analysis. The stability of the PEG/PTFPMS blend composite membrane is investigated with pure N2, O2, and CO2 permeation experiments under the transmembrane pressure difference up to 1.0 MPa. The N2 permeation rate of the PEG400/PTFPMS blend composite membrane with a blend ratio of 0.2 is 2.11 GPU, while the O2/N2 and CO2/N2 selectivities are improved to 2.67 and 26.67, respectively, which are higher than those of pure PTFPMS composite membrane that is 2.2 and 13.79, respectively.

P.1.c.009 The effects of polyamidehydroxyurethane-coated silver nanoparticles on morphine-induced conditioned place preference in rats

Sulfonated polysulfone (sPSf) was prepared and used as a polymer matrix for cation-exchange membranes (CEM). The sulfonation reaction was carried out at room temperature and the degree of sulfonation was calculated by titration method. Blend composite membranes were prepared using different ratios of sPSf and modified chitosan (CS). Membrane properties were studied in terms of water flux, water swelling ratio, molecular weight cut off (MWCO), ion-exchange capacity (IEC) and contact angle measurement. Charge on the membrane was confirmed by ionic diffusion potential (DP). It was observed that, DP increased with the increase in the concentration of sPSf. The membrane sPSf:CS 60:40 showed 1000 Da MWCO, 14.6 mV diffusion potential (DP) and 0.083 mM/g of IEC. Similarly sPSf:CS 90:10 showed 10,000 Da MWCO, 71.7 mV diffusion potential (DP) and 0.176 mM/g of IEC. Moreover, membrane sPSf:CS 60:40 showed 93%, 89% and 69% for MgSO4, Na2SO4 and NaCl rejection respectively.

Effect of monoethylene glycol and triethylene glycol contamination on CO2/CH4 separation of a facilitated transport membrane for natural gas sweetening

A CO2-facilitated transport composite membrane made of PVAm/PVA blend was exposed to a humid synthetic natural gas mixture with monoethylene glycol (MEG) and triethylene glycol (TEG). The effects of different parameters such as relative humidity, types of impurities, exposure temperature were analyzed to understand the real mechanism of interaction and their effects on the CO2/CH4 separation performance. Both the CO2 and CH4 permeances were increased after the exposure of hygroscopic MEG and TEG, except in one case. The CO2/CH4 selectivity was slightly reduced by the exposure to MEG since MEG plasticized the membrane a little bit, whereas the selectivity was slightly increased by the exposure to TEG. Water plays a significant role in the overall performance. For this facilitated transport PVAm/PVA blend membrane, the high relative humidity helps the facilitated transport of CO2 through the PVAm/PVA blend composite membrane to maintain its permeation properties to a value very close to that of a fresh membrane. This study reports the effect of MEG and TEG on the CO2/CH4 separation of a PVAm/PVA blend composite membrane, and documents a positive step forward for using this membrane in a rigorous environment of natural gas sweetening where entrained glycol is considered as a potential threat to the membrane.

Natural gas sweetening—the effect on CO2–CH4 separation after exposing a facilitated transport membrane to hydrogen sulfide and higher hydrocarbons

The PVAm/PVA blend composite membrane was exposed to synthetic natural gas mixtures containing aggressive gases like hydrogen sulfide (H2S) at a concentration of 1mol% and H2S in combination with the condensable hydrocarbons n-hexane and propane. The effect on the performance of the membrane was studied under different relative humidity conditions and the possible interactions between the membrane and impurities were analyzed. The performance of the membrane was found to be reduced at low humidity conditions due to H2S induced conditioning and sorption of n-hexane both in the polysulfone support and PVAm/PVA selective layer, while at high relative humidity the CO2 facilitated transport helps the membrane to retain its performance to a value very close to that of a fresh membrane. The CO2 facilitated transport is closely related to the membrane swelling. The combined effects of H2S and hydrocarbons are comparable to the effects of H2S alone. Under high humidified conditions, the maximum CO2 permeance loss is 18% and the maximum CO2/CH4 selectivity loss is 16% after two weeks exposure at this harsh and humidified conditions. Our conclusion based on the current investigations, is that the aggressive environment does not introduce permanent damage to the material and the PVAm/PVA blend membrane is keeping its separation performance quite well after the exposure to H2S and hydrocarbons, and may have a potential for being used in natural gas sweetening.

Preparation and characterization of sulfonated polysulfone and N-phthloyl chitosan blend composite cation-exchange membrane for desalination

Sulfonated polysulfone (sPSf) was prepared and used as a polymer matrix for cation-exchange membranes (CEM). The sulfonation reaction was carried out at room temperature and the degree of sulfonation was calculated by titration method. Blend composite membranes were prepared using different ratios of sPSf and modified chitosan (CS). Membrane properties were studied in terms of water flux, water swelling ratio, molecular weight cut off (MWCO), ion-exchange capacity (IEC) and contact angle measurement. Charge on the membrane was confirmed by ionic diffusion potential (DP). It was observed that, DP increased with the increase in the concentration of sPSf. The membrane sPSf:CS 60:40 showed 1000Da MWCO, 14.6mV diffusion potential (DP) and 0.083mM/g of IEC. Similarly sPSf:CS 90:10 showed 10,000Da MWCO, 71.7mV diffusion potential (DP) and 0.176mM/g of IEC. Moreover, membrane sPSf:CS 60:40 showed 93%, 89% and 69% for MgSO4, Na2SO4 and NaCl rejection respectively.

REMOVED: Effect of entrained glycols and higher hydrocarbons on the CO2 CH4 separation performance of a PVAm/PVA blend composite membrane

REMOVED: Effect of entrained glycols and higher hydrocarbons on the CO2 CH4 separation performance of a PVAm/PVA blend composite membrane

Effect of cross-linking agent and heteropolyacid (HPA) contents on physicochemical characteristics of covalently cross-linked sulfonated poly(ether ether ketone)/HPAs composite membranes for water electrolysis

In order to improve the mechanical properties while maintaining electrochemical characteristics, engineering plastic of poly(ether ether ketone) as polymer matrix was sulfonated and the organic–inorganic blend composite membranes was prepared by loading 20–50% of HPAs, including tungstophosphoric acid (TPA), molybdophosphoric acid (MoPA) and tungstosilicic acid (TSiA). And then, these composite membranes were covalently cross-linked with the variation of 0.005–0.015 mL of cross linking agent contents (CL-SPEEK/HPA). Also, the characteristics of membrane electrolyte assembly (MEA) were measured in polymer electrolyte membrane electrolysis (PEME) cells. Although cross-linking decreased the number of sulfonic acid groups available for proton transfer in the membrane, the addition of cross-linking agent and HPAs significantly improved the mechanical and electrochemical properties of the membrane. Consequently, the optimum conditions of CL-SPEEK/HPAs with 0.01 mL of cross-linking agent content were established and electrochemical characteristics, such as ion conductivity, was in the order of magnitude: CL-SPEEK/TPA30 (30 wt%) < CL-SPEEK/MoPA40 < CL-SPEEK/TSiA30 and mechanical characteristics such as tensile strength: Nafion117 < CL-SPEEK/TSiA30 < CL-SPEEK/MoPA40 < CL-SPEEK/TPA30. With increasing cross-linking agent content, tensile strength increased and ion conductivity decreased. CL-SPEEK/MoPA40 showed the best electrocatalytic activity of cell voltage 1.71 V at 80 °C among the prepared composite membranes. However, in consideration of high water content, low anti-oxidative property and weak mechanical properties of CL-SPEEK/MoPA40 and CL-SPEEK/TSiA30 membranes, in spite of its high proton conductivity and electrocatalytic activity, it is expected that the CL-SPEEK/TPA30 (1.75 V) was suitable as an alternative membrane in large scale polymer electrolyte membrane electrolysis system. The dual effect of higher proton conductivity and electrocatalytic activity with the addition of HPAs, causes a synergy effect.

Fabrication and characterization of poly(vinyl alcohol)/montmorillonite/poly(styrene sulfonic acid) proton-conducting composite membranes for direct methanol fuel cells

A high performance poly(vinyl alcohol)/montmorillonite/poly(styrene sulfonic acid) (PVA/MMT/PSSA) proton-conducting composite membrane was fabricated by a solution casting method. The characteristic properties of these blend composite membranes were investigated by using thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, methanol permeability measurement, and the AC impedance method. The ionic conductivities for the composite membranes are in the order of 10 −3 S cm −1 at ambient temperature. There are two proton sources used on this novel composite membrane: the modified MMT fillers and PSSA polymer, both materials all contain the –SO 3H group. Therefore, the ionic conductivity was greatly enhanced. The methanol permeabilities of PVA/MMT/PSSA composite membranes is of the order of 10 −7 cm 2 s −1. It is due to the excellent methanol barrier properties of the PVA polymer. The peak power densities of the air-breathing direct methanol fuel cells (DMFCs) with 1M, 2M, 4M CH 3OH fuels were 14.22, 20.00, and 13.09 mW cm −2, respectively, at ambient conditions. The direct methanol fuel cell with this composite polymer membrane exhibited good electrochemical performance. The proposed PVA/MMT/PSSA composite membrane is therefore a potential candidate for future applications in DMFC.

Direct methanol fuel cell based on poly(vinyl alcohol)/titanium oxide nanotubes/poly(styrene sulfonic acid) (PVA/nt-TiO 2/PSSA) composite polymer membrane

The high performance poly(vinyl alcohol)/titanium oxide nanotubes/poly(styrene sulfonic acid) (PVA/nt-TiO 2/PSSA) proton-conducting composite membrane is prepared by a solution casting method. The characteristic properties of these blend composite membranes are investigated by thermal gravimetric analysis (TGA), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX), micro-Raman spectroscopy, dynamic mechanical analysis (DMA), methanol permeability measurement and AC impedance method. It is found that the peak power densities of the DMFC with 1, 2, and 4 M CH 3OH fuels are 12.85, 23.72, and 10.99 mW cm −2, respectively, at room temperature and ambient air. Especially, among three methanol concentrations, the 2 M methanol shows the highest peak power density among three methanol concentrations. The results indicate that the air-breathing direct methanol fuel cell comprised of a novel PVA/nt-TiO 2/PSSA composite polymer membrane has excellent electrochemical performance and stands out as a viable candidate for applications in DMFC.

Effects of pressure and temperature on fixed-site carrier membrane for CO2 separation from natural gas

In this paper, the effect of testing temperature on the performance of fixed carrier membrane for CO2 separation were studied. The blend composite membranes were developed respectively with a blend of PEI-PVA (polyetheleneimine-polyvinyl alcohol) as separation layer and PS (polysulfone) ultrafiltration membranes as the substrates. The permselectivity of the membranes was measured with CO2/CH4 mixed gas. The effect of testing temperature on membrane separation performance was investigated. The results showed that both the permeances of CO2 and CH4 decreased with the increase of temperature, and the permeances decreased more quickly under low pressure than those under high pressure. At the feed pressure of 0.11 MPa, the CO2/ CH4 selectivity of PEI-PVA/PS blend composite membrane reduced along with temperature increment. Under the feed pressure of 0.21 MPa, as well as 1.11 MPa, the selectivity decreased with the increase of temperature.

Blended and Cross‐Linked Ionomer Membranes for Application in Membrane Fuel Cells

AbstractDifferently cross‐linked blend membranes were prepared from commercial arylene main‐chain polymers of the poly(etherketone) and poly(ethersulfone) classes, modified with sulfonate groups, sulfinate cross‐linking groups, and basic N‐groups.The following membrane types have been prepared: (i) Van‐der Waals/dipole‐dipole blends by mixing a polysulfonate with unmodified PSU. This membrane type showed a heterogeneous morphology, leading to extreme swelling and even dissolution of the sulfonated component at elevated temperatures. (ii) Hydrogen bridge blends by mixing a polysulfonate with a polyamide or a polyetherimide. This membrane type showed a partially heterogeneous morphology, also leading to extreme swelling/dissolution of the sulfonated blend component at elevated temperatures. (iii) Acid‐base blends by mixing a polysulfonate with a polymeric N‐base (in‐house developed/commercial). A wide range of properties could be achieved with this membrane type by variation of the different parameters. Membranes showing excellent stability and good fuel cell performance up to 100 °C (PEFC) and 130 °C (DMFC) were obtained. (iv) Covalently cross‐linked (blend) membranes by either mixing a polysulfonate with a polysulfinate or by preparing a polysulfinatesulfonate, followed by reaction of the sulfinate groups in solution with a dihalogeno compound under S‐alkylation. The membranes prepared showed effective suppression of swelling without a loss in the H+‐conductivity. The membranes showed good PEFC (up to 100 °C) and DMFC (up to 130 °C) performance. (v) Covalent‐ionically cross‐linked blend membranes by mixing polysulfonates with polysulfinates and polybases or by mixing a polysulfonate with a polymer carrying both sulfinate and basic N‐groups. The covalent‐ionically cross‐linked membranes were tested in a DMFC up to 110 °C and demonstrated good performance. (vi) Differently cross‐linked organic‐inorganic blend composite membranes via various procedures. The best results were obtained with blend membranes having a layered zirconium phosphate “ZrP” phase: they were transparent, and showed good H+‐conductivity and stability. The application of one of these composite membranes in a PEFC yielded good performance up to T = 115 °C.