scholarly journals Alkali Attack on Cation-Exchange Membranes with Polyvinyl Chloride Backing and Binder: Comparison with Anion-Exchange Membranes

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 228 ◽  
Author(s):  
Shoichi Doi ◽  
Nobuya Takumi ◽  
Yuriko Kakihana ◽  
Mitsuru Higa
Keyword(s):  
Cation Exchange ◽  
Anion Exchange ◽  
Polyvinyl Chloride ◽  
Chemical Structure ◽  
Immersion Test ◽  
Ion Concentration ◽  
Membrane Properties ◽  
Anion Exchange Membranes ◽  
Alkali Solutions ◽  
Exchange Membrane

Systematic alkali immersion tests of cation-exchange membranes (CEM) with polyvinyl chloride (PVC) as their backing and binder were conducted to compare that of an Anion-exchange membrane (AEM) with the same PVC materials to investigate the mechanism of dehydrochlorination. In the immersion tests, originally colorless and transparent AEM turned violet, and chemical structure analysis showed that polyene was produced by the dehydrochlorination reaction. However, the CEM did not change in color, chemical structure or membrane properties during the test with less than 1M alkali solutions. According to the Donnan equilibrium theory and the experiments using CEM and AEM, the hydroxide ion concentration in the CEM was much lower than that in the AEM under the same conditions. However, when the alkali immersion test was performed using the CEM under more severe conditions (6 M for 168 h at 40 °C), there was a slight change in the color and chemical structure of the CEM, clearly indicating that not only AEMs, but also CEMs with PVC matrixes were deteriorated by alkali, depending on the conditions.

STABILITY AND PERFORMANCE EVALUATION OF ION-EXCHANGE MEMBRANES FOR VANADIUM REDOX FLOW BATTERY

2016 ◽  
Vol 78 (12) ◽  
Author(s):  
Saidatul Sophia Sha’rani ◽  
Ebrahim Abouzari Lotf ◽  
Arshad Ahmad ◽  
Wan Atika Wan Ibrahim ◽  
Mohamed Mahmoud El-sayed Nasef ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Anion Exchange ◽  
Chemical Stability ◽  
Ion Selectivity ◽  
Vanadium Redox Flow Battery ◽  
Anion Exchange Membranes ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Exchange Membrane ◽  
Vanadium Redox

The performance of vanadium redox flow battery (VRFB) is highly dependent on the efficiency of the membrane. Generally, anion exchange membranes and cation exchange membranes can be applied in the VRFB. In this paperwork, AMI-7001S anion exchange membrane and CMI-7000S cation exchange membranes were tested for their suitability in the VRFB application. Both of the membranes were originally used for electrocoat and water treatment system. In order to study the behavior of the membranes in the VRFB, several tests were performed. This includes VO2+ ion permeability, ionic conductivity, ion selectivity, chemical stability and single cell performance. The results obtained were compared to Nafion 117 which is a proton exchange membrane. This membrane is one of the most established membranes for VRFB. From the experiment, it can be summarized that the membranes are unsuitable to be used in VRFB. This is due to the low ion selectivity, poor chemical stability and high resistance.

scholarly journals Porous PVDF/PANI ion-exchange membrane (IEM) modified by polyvinylpyrrolidone (PVP) and lithium chloride in the application of membrane capacitive deionisation (MCDI)

2018 ◽  
Vol 77 (9) ◽  
pp. 2311-2319 ◽  
Author(s):  
Yiming Zhang ◽  
Wei Zhang ◽  
Luis F. Cházaro-Ruiz
Keyword(s):  
Ion Exchange ◽  
Water Content ◽  
Anion Exchange ◽  
Lithium Chloride ◽  
Polyvinylidene Fluoride ◽  
Transport Number ◽  
Ion Concentration ◽  
Anion Exchange Membranes ◽  
Drying Time ◽  
Exchange Membrane

Abstract In this work, polyvinylidene fluoride (PVDF)/polyaniline (PANI) heterogeneous anion-exchange membranes filled with pore-forming agents polyvinylpyrrolidone (PVP) and lithium chloride were prepared by the solution-casting technique using the solvent 1-methyl-2-pyrrolidone (NMP) and a two-step phase inversion procedure. Key properties of the as-prepared membranes, such as hydrophilicity, water content, ion exchange capacity, fixed ion concentration, conductivity and transport number were examined and compared between membranes in different conditions. The pore-forming hydrophilic additives PVP and lithium chloride to the casting solution appeared to improve the ion-exchange membranes (IEMs) by increasing the conductivity, transport number and hydrophilicity. The effects of increasing membrane drying time on the porosity of the as-prepared membranes were found to lower membrane porosity by reducing membrane water content. However, pore-forming agents were found to be able to stabilise membrane transport number with different drying times. As-prepared PVDF/PANI anion-exchange membrane with pore-forming agent is demonstrated to be a more efficient candidate for water purification (e.g. desalination) and other industrial applications.

Penyediaan dan Pencirian Membran Pertukaran Kation dengan Resin untuk Proses Elektrodialisis

2012 ◽  
Author(s):  
Mahadevan. M. ◽  
Lay Pee Lin ◽  
Zainal Abidin M. Y. ◽  
Mohamad Roji Sarmidi
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Anion Exchange Membrane ◽  
Cation Exchange Membrane ◽  
Membrane Thickness ◽  
Anion Exchange Membranes ◽  
Exchange Membrane

Elektrodialisis merupakan suatu proses yang menggunakan perbezaan keupayaan elektrik sebagai daya penggerak yang menyebabkan pergerakan ion-ion dalam sesuatu elektronit. Membran yang digunakan dalam proses ini akan membenarkan sama ada cas-cas positif atau negatif sahaja melaluinya bergantung kepada kumpulan berfungsi yang terikat pada membran. Objektif projek penyelidikan ini adalah untuk menghasilkan membran pertukaran kation yang digunakan dalam proses elektrodialisis. Membran-membran pertukaran kation yang dihasilkan terbahagi kepada lima jenis, dan diberi nama sebagai BERL–30, 40, 50, 60, dan 70. Kelima-lima jenis membran ini berbeza dari segi kandungan resin yang berfungsi sebagai vektor pertukaran cas kation. Di samping penyediaan membran, penyelidikan ini juga meliputi aspek pencirian membran tersebut serta perbandingan dengan membran komersial. Kriteria yang dikaji adalah ketebalan membran, sifat kebolehtelapan membran, kapasiti pertukaran ion, kapasiti kepekatan ion kumpulan berfungsi, morfologi struktur membran, ujian kestabilan kimia dan kandungan air membran. Secara keseluruhannya, didapati peratus kandungan resin yang tinggi boleh meningkatkan kapasiti pertukaran ion, peratus kebolehtelapan membran serta kapasiti kepekatan ion kumpulan berfungsi. Antara membran yang dihasilkan, membran pertukaran kation jenis BERL–70 merupakan membran yang berpotensi dalam penggunaan proses elektrodialisis. Kata kunci: Membran pertukaran kation, polisulfona, resin pertukaran ion, ciri-ciri membran, elekrodialisis The objective of this work is to prepare an anion exchange membrane from polysulfone binder–ion exchange resin, which can be used in electrodialysis process. The cation exchange membranes were prepared by the solution casting method. The prepared anion exchange membranes are different from the conventional cation exchange membranes because its functional group is not derived from chlorosulfonic acid but from the absorption of anion exchange resins. The content of resins in each set of the prepared cation exchange membrane varied and were named as BERL–30, 40, 50, 60, and 70. In addition, the performance and behaviour of the prepared anion exchange membrane were evaluated and compared with the commercial cation exchange membranes. The physico-chemical properties of anion exchange membrane were determined by measuring the membrane thickness, permselectivity, and concentration of ion exchange capacity, chemical stability, water content, and scanning electron microscope (SEM). It was found that the increase in the quantity of resin (%) would increase the capacity of ion exchange, percentage of permselectivity, and capacity concentration of ion exchange group. The experimental results showed that cation exchange membrane has the potential to be used in electrodialysis process. Keywords: Cation exchange membrane, electrodialysis, polysulfone, ion exchange resin, membrane characterisation

scholarly journals Inorganic Pseudo Ion Exchange Membranes—Concepts and Preliminary Experiments

2018 ◽  
Vol 8 (11) ◽  
pp. 2142 ◽  
Author(s):  
Joost Veerman ◽  
Damnearn Kunteng
Keyword(s):  
Energy Storage ◽  
Ion Exchange ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Silver Chloride ◽  
Anion Exchange Membranes ◽  
Ion Exchange Membranes ◽  
Salt Solutions ◽  
Silver Plate ◽  
Exchange Membrane

Reverse electrodialysis (RED) is a method to produce electricity from the reversible mixing of two salt solutions with different concentrations. RED was first employed for energy generation using sea and river water. New fields of application are energy storage and heat-to-power conversion. In energy storage applications, a stack operates in ED mode during charge and in RED mode during discharge. In a heat-to-power system, the RED stack produces electricity and the outgoing solutions are returned to their original concentrations in a heat-driven regenerator. In both new applications, the salt solutions are circulated and there is a free choice of the combination of salt and membranes for optimal performance. However, classical polymer-based membranes have some disadvantages: they are less suited for operation at higher temperatures, have reduced permselectivity at higher concentrations, and are rather permeable to water, causing an imbalance of the feed waters. We developed a new concept of pseudo-membrane (PM): a metal sheet (sometimes covered with an insoluble salt) on which opposite electrochemical reactions occur at each side of the metal surface. Because a PM is dissolving at one side and growing at the other side during operation, the current should be inverted periodically. We tested a zinc sheet as a pseudo cation exchange membrane for Zn2+ ions and a silver chloride–covered silver plate as a pseudo anion exchange membrane for Cl− ions in three steps. First, a stack was built with Ag/AgCl membranes in combination with normal cation exchange membranes and operated with NaCl solutions. The next stack was based on Zn membranes together with normal anion exchange membranes. This stack was fed with ZnCl2 solutions. Finally, we tested a stack with zinc and Ag/AgCl pseudo-membranes with a ZnCl2 solution. The latter RED system worked; however, after standing for one night, the stack did not function and appeared to be damaged by redox reactions. This failure was the basis for general considerations about the possibilities of ED and RED hybrid stacks, consisting of a combination of classical and pseudo ion exchange membranes. Finally, we consider the possibility of using intercalation electrodes as a pseudo-membrane.

scholarly journals Phenolphthalein Anilide Based Poly(Ether Sulfone) Block Copolymers Containing Quaternary Ammonium and Imidazolium Cations: Anion Exchange Membrane Materials for Microbial Fuel Cell

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 454
Author(s):  
Aruna Kumar Mohanty ◽  
Young-eun Song ◽  
Jung-rae Kim ◽  
Nowon Kim ◽  
Hyun-jong Paik
Keyword(s):  
Fuel Cell ◽  
Microbial Fuel Cell ◽  
Anion Exchange ◽  
Quaternary Ammonium ◽  
Anion Exchange Membrane ◽  
Anion Exchange Membranes ◽  
Good Thermal Stability ◽  
Imidazolium Cations ◽  
Membrane Morphology ◽  
Exchange Membrane

A class of phenolphthalein anilide (PA)-based poly(ether sulfone) multiblock copolymers containing pendant quaternary ammonium (QA) and imidazolium (IM) groups were synthesized and evaluated as anion exchange membrane (AEM) materials. The AEMs were flexible and mechanically strong with good thermal stability. The ionomeric multiblock copolymer AEMs exhibited well-defined hydrophobic/hydrophilic phase-separated morphology in small-angle X-ray scattering and atomic force microscopy. The distinct nanophase separated membrane morphology in the AEMs resulted in higher conductivity (IECw = 1.3–1.5 mequiv./g, σ(OH−) = 30–38 mS/cm at 20 °C), lower water uptake and swelling. Finally, the membranes were compared in terms of microbial fuel cell performances with the commercial cation and anion exchange membranes. The membranes showed a maximum power density of ~310 mW/m2 (at 0.82 A/m2); 1.7 and 2.8 times higher than the Nafion 117 and FAB-PK-130 membranes, respectively. These results demonstrated that the synthesized AEMs were superior to Nafion 117 and FAB-PK-130 membranes.

scholarly journals Influential Mechanism of Natural Organic Matters with Calcium Ion on the Anion Exchange Membrane Fouling Behavior via xDLVO Theory

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 968
Author(s):  
Zhun Ma ◽  
Lu Zhang ◽  
Ying Liu ◽  
Xiaosheng Ji ◽  
Yuting Xu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Interaction Energy ◽  
Anion Exchange ◽  
Natural Organic Matter ◽  
Calcium Ions ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Anion Exchange Membrane ◽  
Anion Exchange Membranes ◽  
Exchange Membrane

The fouling mechanism of the anion exchange membrane (AEM) induced by natural organic matter (NOM) in the absence and presence of calcium ions was systematically investigated via the extended Derjaguin–Landau–Verwey–Overbeek (xDLVO) approach. Sodium alginate (SA), humic acid (HA), and bovine serum albumin (BSA) were utilized as model NOM fractions. The results indicated that the presence of calcium ions tremendously aggravated the NOM fouling on the anion exchange membrane because of Ca-NOM complex formation. Furthermore, analysis of the interaction energy between the membrane surface and foulants via xDLVO revealed that short-range acid–base (AB) interaction energy played a significant role in the compositions of interaction energy during the electrodialysis (ED) process. The influence of NOM fractions in the presence of calcium ions on membrane fouling followed the order: SA > BSA > HA. This study demonstrated that the interaction energy was a dominating indicator for evaluating the tendency of anion exchange membranes fouling by natural organic matter.

scholarly journals Electrowinning of Iron from Spent Leaching Solutions Using Novel Anion Exchange Membranes

Membranes ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 137
Author(s):  
Wouter Dirk Badenhorst ◽  
Cloete Rossouw ◽  
Hyeongrae Cho ◽  
Jochen Kerres ◽  
Dolf Bruinsma ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Anion Exchange ◽  
Mechanical Stability ◽  
Specific Energy Consumption ◽  
Flow Cell ◽  
Process Efficiency ◽  
Side Reactions ◽  
Anion Exchange Membranes ◽  
Acid Generation ◽  
Exchange Membrane

In the Pyror process, electrowinning (EW) is used to recover acid and iron from spent leaching solutions (SLS), where a porous Terylene membrane acts as a separator between the cathode and anode. In this study, a novel anion exchange membrane (AEM)-based EW process is benchmarked against a process without and with a porous Terylene membrane by comparing the current efficiency, specific energy consumption (SEC), and sulfuric acid generation using an in-house constructed EW flow cell. Using an FAP-PK-130 commercial AEM, it was shown that the AEM-based process was more efficient than the traditional processes. Subsequently, 11 novel polybenzimidazole (PBI)-based blend AEMs were compared with the commercial AEM. The best performing novel AEM (BM-5), yielded a current efficiency of 95% at an SEC of 3.53 kWh/kg Fe, which is a 10% increase in current efficiency and a 0.72 kWh/kg Fe decrease in SEC when compared to the existing Pyror process. Furthermore, the use of the novel BM-5 AEM resulted in a 0.22 kWh/kg Fe lower SEC than that obtained with the commercial AEM, also showing mechanical stability in the EW flow cell. Finally, it was shown that below 5 g/L Fe, side reactions at the cathode resulted in a decrease in process efficiency, while 40 g/L yielded the highest efficiency and lowest SECs.

Dual exchange membrane fuel cell with sequentially aligned cation and anion exchange membranes for non-humidified operation

2020 ◽  
Vol 596 ◽  
pp. 117745 ◽  
Author(s):  
So Young Lee ◽  
Ji Eon Chae ◽  
Jieun Choi ◽  
Hyun Seo Park ◽  
Dirk Henkensmeier ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Anion Exchange ◽  
Anion Exchange Membranes ◽  
Exchange Membrane

Boosting the performance of an anion exchange membrane by the formation of well-connected ion conducting channels

2019 ◽  
Vol 10 (22) ◽  
pp. 2822-2831 ◽  
Author(s):  
Yan Li ◽  
Jujia Zhang ◽  
Hua Yang ◽  
Shanzhong Yang ◽  
Shanfu Lu ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Chemical Structure ◽  
Anion Exchange Membrane ◽  
Efficient Strategy ◽  
Ion Conducting ◽  
Exchange Membrane

Enlarging the discrepancies between hydrophilic/hydrophobic segments in the chemical structure of an ionomer proved to be an efficient strategy to induce the formation of a microphase-separated morphology of the resulting anion exchange membrane.

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