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

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.

RSC Advances ◽  
2019 ◽  
Vol 9 (62) ◽  
pp. 36374-36385
Author(s):  
Chao Wang ◽  
Nengxiu Pan ◽  
Yuliang Jiang ◽  
Junbin Liao ◽  
Arcadio Sotto ◽  
...  

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


2013 ◽  
Vol 773 ◽  
pp. 171-174
Author(s):  
Shou Hai Zhang ◽  
Ben Gui Zhang ◽  
Xi Gao Jian

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.


Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 469
Author(s):  
Elke Herrmann ◽  
Nico Dingenouts ◽  
Christina Roth ◽  
Frieder Scheiba ◽  
Helmut Ehrenberg

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.


2020 ◽  
Vol 3 (11) ◽  
pp. 10660-10668
Author(s):  
Hanzhao Duan ◽  
Xia Cheng ◽  
Lingping Zeng ◽  
Qiang Liao ◽  
Jianchuan Wang ◽  
...  

2015 ◽  
Vol 3 (33) ◽  
pp. 16948-16952 ◽  
Author(s):  
Daishuang Zhang ◽  
Xiaoming Yan ◽  
Gaohong He ◽  
Le Zhang ◽  
Xinhong Liu ◽  
...  

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.


Author(s):  
Lucie Zárybnická ◽  
Eliska Stranska

The present work deals with verification stability of the prepared anion-exchange membrane with surface modification in the time. The surface modification of a commercial ultrafiltration poly(ethersulfone) membrane was carried out graft polymerization. Poly(styrene-co-divinylbenzene-co-4-vinylbenzylchloride) surface layer was covalently attached onto commercial ultrafiltration support layer. The membrane was tested from the point of view of water content, ion-exchange capacity, specific resistance, permselectivity, FT-IR spectroscopy and SEM analysis. The tested characteristics (IEC, permselectivity, resistances, structure) of the prepared membrane were same after one year from preparation. The prepared membranes can find use in electrodialysis processes.


RSC Advances ◽  
2017 ◽  
Vol 7 (75) ◽  
pp. 47726-47737 ◽  
Author(s):  
Wai Hin Lee ◽  
Carol Crean ◽  
John R. Varcoe ◽  
Rachida Bance-Soualhi

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.


2021 ◽  
Vol 22 (3) ◽  
pp. 1415
Author(s):  
Veronika Sarapulova ◽  
Natalia Pismenskaya ◽  
Valentina Titorova ◽  
Mikhail Sharafan ◽  
Yaoming Wang ◽  
...  

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.


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