scholarly journals Transport Characteristics of CJMAED™ Homogeneous Anion Exchange Membranes in Sodium Chloride and Sodium Sulfate Solutions

2021 ◽  
Vol 22 (3) ◽  
pp. 1415
Author(s):  
Veronika Sarapulova ◽  
Natalia Pismenskaya ◽  
Valentina Titorova ◽  
Mikhail Sharafan ◽  
Yaoming Wang ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Volume Fraction ◽  
Exchange Capacity ◽  
Polymer Materials ◽  
Transport Numbers ◽  
Anion Exchange Membranes ◽  
Microheterogeneous Model ◽  
Pass Through ◽  
Pes Membrane

The interplay between the ion exchange capacity, water content and concentration dependences of conductivity, diffusion permeability, and counterion transport numbers (counterion permselectivity) of CJMA-3, CJMA-6 and CJMA-7 (Hefei Chemjoy Polymer Materials Co. Ltd., China) anion-exchange membranes (AEMs) is analyzed using the application of the microheterogeneous model to experimental data. The structure–properties relationship for these membranes is examined when they are bathed by NaCl and Na2SO4 solutions. These results are compared with the characteristics of the well-studied homogenous Neosepta AMX (ASTOM Corporation, Japan) and heterogeneous AMH-PES (Mega a.s., Czech Republic) anion-exchange membranes. It is found that the CJMA-6 membrane has the highest counterion permselectivity (chlorides, sulfates) among the CJMAED series membranes, very close to that of the AMX membrane. The CJMA-3 membrane has the transport characteristics close to the AMH-PES membrane. The CJMA-7 membrane has the lowest exchange capacity and the highest volume fraction of the intergel spaces filled with an equilibrium electroneutral solution. These properties predetermine the lowest counterion transport number in CJMA-7 among other investigated AEMs, which nevertheless does not fall below 0.87 even in 1.0 eq L−1 solutions of NaCl or Na2SO4. One of the reasons for the decrease in the permselectivity of CJMAED membranes is the extended macropores, which are localized at the ion-exchange material/reinforcing cloth boundaries. In relatively concentrated solutions, the electric current prefers to pass through these well-conductive but nonselective macropores rather than the highly selective but low-conductive elements of the gel phase. It is shown that the counterion permselectivity of the CJMA-7 membrane can be significantly improved by coating its surface with a dense homogeneous ion-exchange film.

scholarly journals Preparation of Two-Layer Anion-Exchange Poly(ethersulfone) Based Membrane: Effect of Surface Modification

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lucie Zarybnicka ◽  
Eliska Stranska ◽  
Jana Machotova ◽  
Gabriela Lencova
Keyword(s):  
Surface Layer ◽  
Surface Modification ◽  
Ion Exchange ◽  
Anion Exchange ◽  
Exchange Capacity ◽  
Sem Analysis ◽  
Electrochemical Characteristics ◽  
Anion Exchange Membranes ◽  
Ion Exchange Capacity ◽  
Effect Of Surface

The present work deals with the surface modification of a commercial microfiltration poly(ethersulfone) membrane by graft polymerization technique. Poly(styrene-co-divinylbenzene-co-4-vinylbenzylchloride) surface layer was covalently attached onto the poly(ethersulfone) support layer to improve the membrane electrochemical properties. Followed by amination, a two-layer anion-exchange membrane was prepared. The effect of surface layer treatment using the extraction in various solvents on membrane morphological and electrochemical characteristics was studied. The membranes were tested from the point of view of water content, ion-exchange capacity, specific resistance, permselectivity, FT-IR spectroscopy, and SEM analysis. It was found that the two-layer anion-exchange membranes after the extraction using tetrahydrofuran or toluene exhibited smooth and porous surface layer, which resulted in improved ion-exchange capacity, electrical resistance, and permselectivity of the membranes.

scholarly journals A facile approach to prepare crosslinked polysulfone-based anion exchange membranes with enhanced alkali resistance and dimensional stability

RSC Advances ◽  
2019 ◽  
Vol 9 (62) ◽  
pp. 36374-36385
Author(s):  
Chao Wang ◽  
Nengxiu Pan ◽  
Yuliang Jiang ◽  
Junbin Liao ◽  
Arcadio Sotto ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Dimensional Stability ◽  
Synthesis Method ◽  
Exchange Capacity ◽  
Alkali Resistance ◽  
Anion Exchange Membranes ◽  
Facile Synthesis ◽  
Ion Exchange Capacity ◽  
Alkali Stability

Novel anion exchange membranes with enhanced ion exchange capacity, dimensional stability and alkali stability were prepared by a facile synthesis method.

Preparation and Properties of Poly (phthalazinone Ether Ketone) Based Anion Exchange Membranes for Vanadium Redox Flow Battery

2013 ◽  
Vol 773 ◽  
pp. 171-174
Author(s):  
Shou Hai Zhang ◽  
Ben Gui Zhang ◽  
Xi Gao Jian
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Exchange Capacity ◽  
Vanadium Redox Flow Battery ◽  
Anion Exchange Membranes ◽  
Redox Flow Battery ◽  
Flow Battery ◽  
Ion Exchange Capacity ◽  
Ether Ketone ◽  
Vanadium Redox

Poly (phthalazinone ether ketone) anion exchange membranes with pyridinium groups (PyPPEK) for vanadium redox flow battery were prepared from chloromethylated poly (phthalazinone ether ketone) and pyridine. The chemical structure of PyPPEK was characterized by using FT-IR spectrum. Compared with quaternary ammonium group containing poly (phthalazinone ether ketone), PyPPEK membrane showed low ion exchange capacity, low swelling ratio and comparable tensile strength. Columbic efficiencies of VRB with anion exchange membranes were higher than that of VRB with Nafion117 membrane. When the ion exchange capacity of PyPPEK membrane was 1.40 mmol·g-1, energy efficiency of VRB with the membrane was higher than that of VRB with Nafion117 membrane at charge-discharge current densities ranging from 20 mA·cm-2 to 50 mA·cm-2.

scholarly journals Systematic Characterization of Degraded Anion Exchange Membranes Retrieved from Vanadium Redox Flow Battery Field Tests

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 469
Author(s):  
Elke Herrmann ◽  
Nico Dingenouts ◽  
Christina Roth ◽  
Frieder Scheiba ◽  
Helmut Ehrenberg
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Field Tests ◽  
Exchange Capacity ◽  
Vanadium Redox Flow Battery ◽  
Ex Situ ◽  
Anion Exchange Membranes ◽  
Ion Exchange Capacity ◽  
Swelling Power

Commercially available anion exchange membranes were retrieved from VRFB field tests and their degradation due to the various operation conditions is analyzed by in-situ and ex-situ measurements. Ion exchange capacity, permeability and swelling power are used as direct criteria for irreversible changes. Small-angle X-ray scattering (SAXS) and Differential scanning calorimetry (DSC) analyses are used as fingerprint methods and provide information about the morphology and change of the structural properties. A decrease in crystallinity can be detected due to membrane degradation, and, in addition, an indication of reduced polymer chain length is found. While the proton diffusion either increase or decline significantly, the ion exchange capacity and swelling power both are reduced. The observed extent of changes was in good agreement with in-situ measurements in a test cell, where the coulombic and voltage efficiencies are reduced compared to a pristine reference material due to the degradation process.

scholarly journals Nitrate-Selective Anion Exchange Membranes Prepared using Discarded Reverse Osmosis Membranes as Support

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 377
Author(s):  
Amaia Lejarazu-Larrañaga ◽  
Juan Manuel Ortiz ◽  
Serena Molina ◽  
Yan Zhao ◽  
Eloy García-Calvo
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Reverse Osmosis ◽  
Current Density ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Transport Numbers ◽  
Anion Exchange Membranes ◽  
Filtration Membrane ◽  
Reverse Osmosis Membranes

The present work shows a methodology for the preparation of membranes with a high affinity for nitrates. For this purpose, a polymeric mixture containing an anion exchange resin was extended on a recycled pressure filtration membrane used as mechanical support. Different ion exchange resins were tested. The influence in ion fractionation of (i) the type of ion exchange resin, (ii) the use of a recycled membrane as support and (iii) the operating current density during the separation process were studied. Results revealed that the employed anion exchange resin could tune up the transport numbers of the anions in the membrane and enhance the transport of nitrates over sulfates. The use of the recycled filtration membrane as support further increased the transport of nitrates in detriment of sulfates in nitrate-selective membranes. Moreover, it considerably improved the mechanical stability of the membranes. Lowering the operational current density also boosted ion fractionation. In addition, the use of recycled membranes as support in membrane preparation is presented as an alternative management route of discarded reverse osmosis membranes, coupling with the challenging management of waste generated by the desalination industry. These membranes could be used for nitrate recovery from wastewater or for nitrate separation from groundwater.

scholarly journals Transport Characteristics of Fujifilm Ion-Exchange Membranes as Compared to Homogeneous Membranes АМХ and СМХ and to Heterogeneous Membranes MK-40 and MA-41

Membranes ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 84 ◽  
Author(s):  
Sarapulova ◽  
Shkorkina ◽  
Mareev ◽  
Pismenskaya ◽  
Kononenko ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Volume Fraction ◽  
Transport Numbers ◽  
Type I ◽  
Type Ii ◽  
Ion Exchange Membranes ◽  
Electrospinning Method ◽  
Microheterogeneous Model ◽  
First Time

Ion-exchange membranes (IEMs) find more and more applications; the success of an application depends on the properties of the membranes selected for its realization. For the first time, the results of a comprehensive characterization of the transport properties of IEMs from three manufactures (Astom, Japan; Shchekinoazot, Russia; and Fujifilm, The Netherlands) are reported. Our own and literature data are presented and analyzed using the microheterogeneous model. Homogeneous Neosepta AMX and CMX (Astom), heterogeneous MA-41 and MK-40 (Shchekinoazot), and AEM Type-I, AEM Type-II, AEM Type-X, as well as CEM Type-I, CEM Type-II, and CEM Type-X produced by the electrospinning method (Fujifim) were studied. The concentration dependencies of the conductivity, diffusion permeability, as well as the real and apparent ion transport numbers in these membranes were measured. The counterion transport number characterizing the membrane permselectivity increases in the following order: CEM Type-I MA-41 < AEM Type-I < MK-40<CMX CEM Type-II CEM Type-X AEM Type-II < AMX < AEM Type-X. It is shown that the properties of the AEM Type-I and CEM Type-I membranes are close to those of the heterogeneous MA-41 and MK-40 membranes, while the properties of Fujifilm Type-II and Type-X membranes are close to those of the homogeneous AMX and CMX membranes. This difference is related to the fact that the Type-I membranes have a relatively high parameter f2, the volume fraction of the electroneutral solution filling the intergel spaces. This high value is apparently due to the open-ended pores, formed by the reinforcing fabric filaments of the Type-I membranes, which protrude above the surface of these membranes.

Achieving High Conductivity at Low Ion Exchange Capacity for Anion Exchange Membranes with Electrospun Polyelectrolyte Nanofibers

2020 ◽  
Vol 3 (11) ◽  
pp. 10660-10668
Author(s):  
Hanzhao Duan ◽  
Xia Cheng ◽  
Lingping Zeng ◽  
Qiang Liao ◽  
Jianchuan Wang ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Exchange Capacity ◽  
High Conductivity ◽  
Anion Exchange Membranes ◽  
Ion Exchange Capacity

An integrally thin skinned asymmetric architecture design for advanced anion exchange membranes for vanadium flow batteries

2015 ◽  
Vol 3 (33) ◽  
pp. 16948-16952 ◽  
Author(s):  
Daishuang Zhang ◽  
Xiaoming Yan ◽  
Gaohong He ◽  
Le Zhang ◽  
Xinhong Liu ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Exchange Capacity ◽  
Anion Exchange Membrane ◽  
Architecture Design ◽  
Anion Exchange Membranes ◽  
Ion Exchange Membranes ◽  
Ion Exchange Capacity ◽  
Flow Batteries ◽  
Exchange Membrane

We proposed an integrally thin skinned asymmetric anion exchange membrane with sufficiently low ion exchange capacity for vanadium flow batteries (VFBs), and this work provides new insights into the design, fabrication and commercialization of ion exchange membranes for VFBs.

scholarly journals A Raman spectro-microscopic investigation of ETFE-based radiation-grafted anion-exchange membranes

RSC Advances ◽  
2017 ◽  
Vol 7 (75) ◽  
pp. 47726-47737 ◽  
Author(s):  
Wai Hin Lee ◽  
Carol Crean ◽  
John R. Varcoe ◽  
Rachida Bance-Soualhi
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Cross Section ◽  
Microscopic Investigation ◽  
Exchange Capacity ◽  
Anion Exchange Membrane ◽  
Anion Exchange Membranes ◽  
Ion Exchange Capacity ◽  
Exchange Membrane

Raman spectro-microscopy on a radiation-grafted anion-exchange membrane detected alkali degradation throughout its cross-section that quantitatively matched loss of ion-exchange capacity.

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