scholarly journals Nanocomposite Anion Exchange Membranes with a Conductive Semi-Interpenetrating Silica Network

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 260
Author(s):  
Emanuela Sgreccia ◽  
Maria Luisa Di Vona ◽  
Simonetta Antonaroli ◽  
Gianfranco Ercolani ◽  
Marco Sette ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Hybrid Composites ◽  
Degradation Mechanism ◽  
Sol Gel ◽  
Exchange Capacity ◽  
Ex Situ ◽  
Anion Exchange Membranes ◽  
Trimethylammonium Chloride ◽  
Silica Network ◽  
Single Precursor

Nanocomposite anion exchange membranes were synthesized based on poly(sulfone trimethylammonium) chloride. A hybrid semi-interpenetrating silica network containing a large amount of quaternary ammonium groups was prepared by two sol–gel routes, in situ with a single precursor, N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (TMSP), or ex situ mixing two precursors, TMSP and 3-(2-aminoethylamino)propyldimethoxy-methylsilane (AEAPS). The properties of these hybrid composites and their degradation after immersion in 1 M KOH at 60 °C were studied. The degradation is reduced in the composite materials with a lower decrease in the ion exchange capacity. FTIR spectra showed that a main degradation mechanism with a single precursor TMSP is the dissolution of the hybrid silica network in KOH, whereas it is stable with the mixture of TMSP/AEASP. This conclusion is in agreement with the thermogravimetric analysis. The mechanical properties show a better ductility with a single precursor and higher stiffness and strength, but less ductility, by the ex situ route. The activation energy was between 0.25 and 0.14 eV for Cl and OH ion conduction, respectively, consistent with the migration mechanism.

scholarly journals Higher Acid Recovery Efficiency of Novel Functionalized Inorganic/Organic Composite Anion Exchange Membranes from Acidic Wastewater

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 133
Author(s):  
Muhammad Imran Khan ◽  
Abdallah Shanableh ◽  
Noureddine Elboughdiri ◽  
Karim Kriaa ◽  
Djamel Ghernaout ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Mechanical Stability ◽  
Filler Particle ◽  
Exchange Capacity ◽  
Inorganic Filler ◽  
Anion Exchange Membranes ◽  
Trimethylammonium Chloride ◽  
Severe Condition ◽  
Acid Recovery ◽  
Diffusion Dialysis

In this work, the synthesis of a series of the functionalized inorganic/organic composite anion exchange membranes (AEMs) was carried out by employing the varying amount of inorganic filler consist of N-(trimethoxysilylpropyl)-N,N,N-trimethylammonium chloride (TMSP-TMA+Cl−) into the quaternized poly (2, 6-dimethyl-1, 4-phenylene oxide) (QPPO) matrix for acid recovery via diffusion dialysis (DD) process. Fourier transform infrared (FTIR) spectroscopy clearly demonstrated the fabrication of the functionalized inorganic/organic composite AEMs and the subsequent membrane characteristic measurements such as ion exchange capacity (IEC), linear swelling ratio (LSR), and water uptake (WR) gave us the optimum loading condition of the filler without undesirable filler particle aggregation. These composite AEMs exhibited IEC of 2.18 to 2.29 meq/g, LSR of 13.33 to 18.52%, and WR of 46.11 to 81.66% with sufficient thermal, chemical, and mechanical stability. The diffusion dialysis (DD) test for acid recovery from artificial acid wastewater of HCl/FeCl2 showed high acid DD coefficient (UH+) (0.022 to 0.025 m/h) and high separation factor (S) (139-260) compared with the commercial membrane. Furthermore, the developed AEMs was acceptably stable (weight loss < 20%) in the acid wastewater at 60 °C as an accelerated severe condition for 2 weeks. These results clearly indicated that the developed AEMs have sufficient potential for acid recovery application by DD process.

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 Silica Containing Composite Anion Exchange Membranes by Sol–Gel Synthesis: A Short Review

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1874
Author(s):  
Emanuela Sgreccia ◽  
Riccardo Narducci ◽  
Philippe Knauth ◽  
Maria Luisa Di Vona
Keyword(s):  
Anion Exchange ◽  
Sol Gel ◽  
Water Flux ◽  
Short Review ◽  
Anion Exchange Membranes ◽  
Silica Network ◽  
Energy Technologies ◽  
Sol Gel Synthesis ◽  
Diffusion Dialysis ◽  
Future Topics

This short review summarizes the literature on composite anion exchange membranes (AEM) containing an organo-silica network formed by sol–gel chemistry. The article covers AEM for diffusion dialysis (DD), for electrochemical energy technologies including fuel cells and redox flow batteries, and for electrodialysis. By applying a vast variety of organically modified silica compounds (ORMOSIL), many composite AEM reported in the last 15 years are based on poly (vinylalcohol) (PVA) or poly (2,6-dimethyl-1,4-phenylene oxide) (PPO) used as polymer matrix. The most stringent requirements are high permselectivity and water flux for DD membranes, while high ionic conductivity is essential for electrochemical applications. Furthermore, the alkaline stability of AEM for fuel cell applications remains a challenging problem that is not yet solved. Possible future topics of investigation on composite AEM containing an organo-silica network are also discussed.

scholarly journals Innovative BPPO Anion Exchange Membranes Formulation Using Diffusion Dialysis-Enhanced Acid Regeneration System

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 311
Author(s):  
Muhammad Imran Khan ◽  
Majeda Khraisheh ◽  
Fares AlMomani
Keyword(s):  
Anion Exchange ◽  
Room Temperature ◽  
Feed Solution ◽  
Exchange Capacity ◽  
Anion Exchange Membranes ◽  
Regeneration System ◽  
Waste Streams ◽  
Acid Recovery ◽  
Aqueous Waste ◽  
Diffusion Dialysis

Recycling of acid from aqueous waste streams is crucial not only from the environmental point of view but also for maturing the feasible method (diffusion dialysis). Anion exchange membrane (AEM)–based diffusion dialysis process is one of the beneficial ways to recover acid from aqueous waste streams. In this article, the synthesis of a series of brominated poly (2, 6–dimethyl-1, 4–phenylene oxide) (BPPO)-based anion exchange membranes (AEMs) through quaternization with triphenylphosphine (TPP) were reported for acid recovery via diffusion dialysis process. The successful synthesis of the prepared membranes was confirmed by Fourier transform infrared (FTIR) spectroscopy. The as-synthesized anion exchange membranes represented water uptake (WR) of 44 to 66%, ion exchange capacity of (IEC) of 1.22 to 1.86 mmol/g, and linear swelling ratio (LSR) of 8 to 20%. They exhibited excellent thermal, mechanical, and acid stability. They showed homogeneous morphology. The acid recovery performance of the synthesized AEMs was investigated in a two compartment stack using simulated mixture of HCl and FeCl2 as feed solution at room temperature. For the synthesized anion exchange membranes TPP–43 to TPP–100, the diffusion dialysis coefficient of acid (UH+) was in the range of 6.7 to 26.3 (10−3 m/h) whereas separation factor (S) was in the range of 27 to 49 at 25 °C. Obtained results revealed that diffusion dialysis performance of the synthesized AEMs was higher than the commercial membrane DF–120B (UH+ = 0.004 m/h, S = 24.3) at room temperature. It showed that the prepared AEMs here could be excellent candidates for the diffusion dialysis process.

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.

Side-chain-type anion exchange membranes for vanadium flow battery: properties and degradation mechanism

2018 ◽  
Vol 6 (45) ◽  
pp. 22778-22789 ◽  
Author(s):  
Yi Xing ◽  
Lei Liu ◽  
Chenyi Wang ◽  
Nanwen Li
Keyword(s):  
Anion Exchange ◽  
Degradation Mechanism ◽  
Side Chain ◽  
Anion Exchange Membranes ◽  
Flow Battery ◽  
Chain Type

Several side-chain-type AEMs have been synthesized for exploring the effect of the chemical architecture on the performance and degradation mechanism in the vanadium flow battery (VFB).

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.

Facile construction of crosslinked all-carbon-backbone anion-exchange membranes with robust durability

2018 ◽  
Vol 6 (48) ◽  
pp. 24831-24840 ◽  
Author(s):  
Ling Li ◽  
Qian Yang ◽  
Xue Lang Gao ◽  
Hong Yue Wu ◽  
Qiu Gen Zhang ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Exchange Capacity ◽  
Anion Exchange Membranes ◽  
Ionic Exchange ◽  
Carbon Backbone ◽  
Stable Anion

With the aim of preparing highly alkaline stable anion-exchange membranes (AEMs) with desirable ionic exchange capacity (IEC) and swelling, a series of crosslinked poly(4-vinylphenol) (PVP)-based membranes was prepared.

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