a-c electrical properties of bipolar membranes: Experiments and a model

Simons, R.; Sajkewycz, N.

doi:10.1007/bf01870303

Cited by 17 publications

(12 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first and third account for the admittance of the BM junc-tion as described in [73], where the transport of only the two salt ions was considered. This corresponds to d L = d R The admittance of Eq.…”

Section: U(x; T ) = U(x) + Ic(x)ejwtmentioning

confidence: 99%

Electrochemical characterization of polymer ion‐exchange bipolar membranes

1997

View full text Add to dashboard Cite

A bipolar membrane (BM) is a layered structure composed of one cation and one anion ion-exchange layers joined together in series. Polymer BMs offer promising applications for many industrial processes (e. g., the use of bipolar electrodialysis for environmentally clean technologies and the treatment of salt-water effluents) because of their unique electrochemical properties. The most important of these properties is the electric field enhanced (Em) water dissociation which arises when an electric current is forced through the membrane. This phenomenon occurs at the bipolar junction of the BM, and its coupling with ion transport, though still poorly understood, is the basis of most of the potential applications of BMs. In this review, we will focus on recent work concerning the physical chemistry of BMs and give a general overview of their electrochemical properties, emphasizing both theoretical and experimental aspects. We will model first the electric double layer at the bipolar junction between the two ion-exchange layers, and describe then the EFE water dissociation occurring in this junction. Later, we will present in detail a complete theoretical model for the coupling of ion transport and water dissociation in BMs, and show that this model is able to explain the experimental trends observed in the electrochemical characterization of polymer BMs by means of membrane potential, current-voltage curve, and impedance measurements. Acta Polymer., 48,234-250 0 VCH Verlagsgesellschaft mbH, D-69451 Weinheim 1997

show abstract

Section: U(x; T ) = U(x) + Ic(x)ejwtmentioning

confidence: 99%

Electrochemical characterization of polymer ion‐exchange bipolar membranes

1997

View full text Add to dashboard Cite

show abstract

“…The resistance ( R n ) at the neck constantly contributes to the total impedance regardless of the direction of bias, since it comes from the geometry of the microchannel between the two electrodes. Thus R n is added to the equivalent circuit in series as shown in Figure 31. In the presence of negative and positive polyelectrolyte plugs, a parallel component should be considered.…”

Section: Resultsmentioning

confidence: 99%

Ion Flow Crossing Over a Polyelectrolyte Diode on a Microfluidic Chip

Han

Kim

Bae

et al. 2011

Small

View full text Add to dashboard Cite

Key evidences are reported for the rectification mechanism of an aqueous ion diode based on polyelectrolytic plugs on a microfluidic chip by monitoring the ion flow crossing over the junction. The ion flow penetrating the polyelectrolyte junction is visualized by employing a fluorescent chemodosimeter, rhodamine B hydrazide and the pH-dependent dye, carboxy-fluorescein. How hysteresis phenomena, exhibited through the nonlinear behavior of the polyelectrolyte diode, are affected by a variety of parameters (e.g., switching potential, scan rate, and electrolyte concentration) is also investigated. The insights and knowledge from this study provide a crucial foundation for ion control at the iontronic diode in the aqueous phase, leading to more advanced aqueous organic computing devices and more diverse applications for microfluidic logic devices.

show abstract

“…This phenomenon is similar to the charge fluctuations occurring on the metal plates of a capacitor. Thus, the discontinuity in Ĵ 2 can be written in the form 24,28 where C is the geometrical capacitance of the junction 1 and A is the membrane area.…”

Section: Cation Exchange Layersmentioning

confidence: 99%

“…The theoretical approach is based on the Nernst-Planck and Poisson equations and reproduces the results obtained by previous models 28,30 taking the appropriate limiting cases. The crucial part of the paper is the setting up of the model for the field dependence of the rate of dissociation of water in the space charge region existing at the interface between the two ion-exchange layers of the bipolar membrane.…”

Section: Introductionmentioning

confidence: 95%

“…Complex impedance plots are of particular importance for charged membranes, and several theoretical models are available. − The problem of the ac impedance in BM's has also been treated extensively in the literature. Chilcott et al , have presented recently a theoretical model accounting for the impedance spectra of BM's based on previous analyses. − The model, which considers only the salt ions and cannot thus be applied to the case of water dissociation, seems to be useful for the description of biological systems over a wide range of frequencies. Other attempts , have been focused on the study of the ac spectra of synthetic BM's separating acid−base solutions by using a model characteristic of the electrode/solution interface.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Simple Model for Ac Impedance Spectra in Bipolar Membranes

et al. 1996

View full text Add to dashboard Cite

A new model accounting for the ac impedance spectra of synthetic ion-exchange bipolar membranes is presented. The theoretical approach is based on the Nernst-Planck and Poisson equations and applies some of the concepts used in the semiconductor pn junctions to the case of a bipolar membrane. The results presented are the current-voltage curves and the impedance spectra at electric currents above the limiting current. It is shown that the model is able to identify the main contributions to the bipolar membrane impedance and gives valuable information about the bipolar junction structure and its influence on the characteristic parameters involved in the field-enhanced water dissociation phenomenon.

show abstract

a-c electrical properties of bipolar membranes: Experiments and a model

Cited by 17 publications

References 12 publications

Electrochemical characterization of polymer ion‐exchange bipolar membranes

Electrochemical characterization of polymer ion‐exchange bipolar membranes

Ion Flow Crossing Over a Polyelectrolyte Diode on a Microfluidic Chip

A Simple Model for Ac Impedance Spectra in Bipolar Membranes

Contact Info

Product

Resources

About