The balance of electric field and interfacial catalysis in promoting water dissociation in bipolar membranes

2018 ◽  
Vol 11 (8) ◽  
pp. 2235-2245 ◽  
Author(s):  
Zhifei Yan ◽  
Liang Zhu ◽  
Yuguang C. Li ◽  
Ryszard J. Wycisk ◽  
Peter N. Pintauro ◽  
...  
Keyword(s):  
Electric Field ◽  
Anion Exchange ◽  
Water Dissociation ◽  
Bipolar Membranes ◽  
Electrolytic Cells ◽  
Interfacial Catalysis

Bipolar membranes maintain a steady pH in electrolytic cells through water autodissociation at the interface between their cation- and anion-exchange layers. We analyze the balance of electric field and catalysis in accelerating this reaction.

Bipolar membrane polarization behavior with systematically varied interfacial areas in the junction region

2021 ◽  
Author(s):  
Subarna Kole ◽  
Gokul Venugopalan ◽  
Deepra Bhattacharya ◽  
Le Zhang ◽  
John Cheng ◽  
...  
Keyword(s):  
Electric Field ◽  
Water Dissociation ◽  
Bipolar Membrane ◽  
Junction Region ◽  
Bipolar Membranes ◽  
Membrane Polarization ◽  
Interfacial Areas ◽  
Left Image ◽  
The Right ◽  
The Relationship

Left image is the relationship for the overpotential for water dissociation as a function of bipolar junction electric field whereas the right image presents micrographs and the procedure to make bipolar membranes with micropatterned interfaces.

scholarly journals Radiation-Induced Asymmetric Grafting of Different Monomers into Base Films to Prepare Novel Bipolar Membranes

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2028
Author(s):  
Shin-ichi Sawada ◽  
Yasunari Maekawa
Keyword(s):  
Acrylic Acid ◽  
Anion Exchange ◽  
Graft Polymerization ◽  
The Other ◽  
Practical Applications ◽  
Bipolar Membranes ◽  
Graft Polymers ◽  
Grafting Reactions ◽  
Radiation Induced

We prepared novel bipolar membranes (BPMs) consisting of cation and anion exchange layers (CEL and AEL) using radiation-induced asymmetric graft polymerization (RIAGP). In this technique, graft polymers containing cation and anion exchange groups were introduced into a base film from each side. To create a clear CEL/AEL boundary, grafting reactions were performed from each surface side using two graft monomer solutions, which are immiscible in each other. Sodium p-styrenesulfonate (SSS) and acrylic acid (AA) in water were co-grafted from one side of the base ethylene-co-tetrafluoroethylene film, and chloromethyl styrene (CMS) in xylene was simultaneously grafted from the other side, and then the CMS units were quaternized to afford a BPM. The distinct SSS + AA- and CMS-grafted layers were formed owing to the immiscibility of hydrophilic SSS + AA and hydrophobic CMS monomer solutions. This is the first BPM with a clear CEL/AEL boundary prepared by RIAGP. However, in this BPM, the CEL was considerably thinner than the AEL, which may be a problem in practical applications. Then, by using different starting times of the first SSS+AA and second CMS grafting reactions, the CEL and AEL thicknesses was found to be controlled in RIAGP.

scholarly journals Mg/Al double-metal hydroxide regeneration of anion exchange resin by electric field intensification

2016 ◽  
Vol 75 (6) ◽  
pp. 1309-1318 ◽  
Author(s):  
Ying Wang ◽  
Zhun Li ◽  
Yansheng Li ◽  
Zhigang Liu
Keyword(s):  
Electric Field ◽  
Anion Exchange ◽  
Exchange Resin ◽  
Ph Value ◽  
Anion Exchange Resin ◽  
Cost Effective ◽  
Regenerative Capacity ◽  
Metal Hydroxides ◽  
Anion Exchange Resins ◽  
Exchange Resins

Fouled anion exchange resins were regenerated by electric field intensification of Mg/Al double-metal hydroxides. Regenerative experiments were performed with varying voltages (10–30 V) and dosages of Mg/Al hydroxides (0.045–0.135 mol and 0.015–0.045 mol, respectively) for 1–5 h. Optimal results were obtained under the following regenerative conditions: 20 V, 4 h, and 0.09/0.03 mol of Mg/Al hydroxides. The maximum regenerative capacity of resins was increased to 41.07%. The regenerative mechanism was presented by Fourier-transform infrared spectrum of resins and Mg/Al hydroxides, and the regenerative degree was analyzed with respect to conductivity, pH value, and electric current. Mg/Al hydroxides were also recycled after the regeneration. This method was proven to be cost-effective and environmentally friendly.

Transient effects in electrolytic cells submitted to an external electric field

2006 ◽  
Vol 33 (10) ◽  
pp. 1177-1187 ◽  
Author(s):  
A. L. Alexe‐Ionescu ◽  
G. Barbero ◽  
F. C. M. Freire ◽  
M. Scalerandi
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Transient Effects ◽  
Electrolytic Cells

scholarly journals Mass Transfer Phenomena during Electrodialysis of Multivalent Ions: Chemical Equilibria and Overlimiting Currents

2018 ◽  
Vol 8 (9) ◽  
pp. 1566 ◽  
Author(s):  
Manuel Martí-Calatayud ◽  
Montserrat García-Gabaldón ◽  
Valentín Pérez-Herranz
Keyword(s):  
Mass Transfer ◽  
Electric Field ◽  
Membrane Surface ◽  
Industrial Effluents ◽  
Water Dissociation ◽  
Chemical Equilibria ◽  
Multivalent Ions ◽  
Current Voltage ◽  
Weak Electrolytes ◽  
New Applications

Electrodialysis is utilized for the deionization of saline streams, usually formed by strong electrolytes. Recently, interest in new applications involving the transport of weak electrolytes through ion-exchange membranes has increased. Clear examples of such applications are the recovery of valuable metal ions from industrial effluents, such as electronic wastes or mining industries. Weak electrolytes give rise to a variety of ions with different valence, charge sign and transport properties. Moreover, development of concentration polarization under the application of an electric field promotes changes in the chemical equilibrium, thus making more complex understanding of mass transfer phenomena in such systems. This investigation presents a set of experiments conducted with salts of multivalent metals with the aim to provide better understanding on the involved mass transfer phenomena. Chronopotentiometric experiments and current-voltage characteristics confirm that shifts in chemical equilibria can take place simultaneous to the activation of overlimiting mass transfer mechanisms, that is, electroconvection and water dissociation. Electroconvection has been proven to affect the type of precipitates formed at the membrane surface thus suppressing the simultaneous dissociation of water. For some electrolytes, shifts in the chemical equilibria forced by an imposed electric field generate new charge carriers at specific current regimes, thus reducing the system resistance.

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