Water uptake and salt transport through Nafion cation-exchange membranes with different thicknesses

Izquierdo-Gil, M.A.; Barragán, V.M.; Villaluenga, J.P.G.; Godino, M.P.

doi:10.1016/j.ces.2011.12.040

Cited by 64 publications

(45 citation statements)

References 39 publications

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“…Indeed, for moderate ly and highly cross-linked ion-exchanger s, swelling increases with the counter-ion hydration whereas this order may be partially or completely reversed in very highly cross-link ed ion-exch angers due to incomplete solvation. Various experime ntal methods were proposed and used to characterize ion-exchange membran e swelling such as the determination of the water content which is considered to be a key parameter in the transport behavior [21,22]. Indeed, the water content can be used to characteri ze the hydration state of the membran e and to give an image of possible structural modifications of it.…”

Section: Influence Of the Membrane Soakingmentioning

confidence: 99%

“…The influence of the nature of the counter-ion on the water content has been mainly investigated with Nafion cation-exchange membranes for which the water content values range between 4 and 30% according to the nature of the counter-ion. It was reported that the water content increases for decreasing atomic number or size of the cation and that the water content rises for increasing hydration number of the counter-ion [22][23][24][25]. In the case of alkali ions, the water content increases according to the following sequence: Cs + < K + < Na + < Li + .…”

Section: Influence Of the Membrane Soakingmentioning

confidence: 99%

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Influence of the ionic composition on the diffusion mass transfer of saccharides through a cation-exchange membrane

Galier¹,

Savignac²,

Balmann³

2013

Separation and Purification Technology

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Recent studies have pointed out that the presence of salts can change significantly the membrane process performances because of the resulting modification of the neutral solutes transfer through the membrane. The influence of the ionic composition on the transfer of neutral solutes through membranes could be explained by a modification of the membrane properties, due to electrostatic effects, by a modification of the solute radius, likely due to its dehydration induced by the electrolyte, or more probably by a combination of both. This study deals with the investigat ion of the mechanisms governing the mass transfer of neutral species through an ion-exchange membrane used in electrodialysis, CMX, with a focus on the role of ions. The mass transfer of various saccharides (xylose, glucose and sucrose) as well as the solvent transfer in different electrolytic solutions (NaCl, NH 4 Cl, CaCl 2 and MgCl 2) was studied in a diffusion regime. A specific procedure has been used to dissociate the solvent or solute fluxes variations due to the modifications of the solute properties and of the membrane material induced by the electrolyte. The results showed that the transfer modification is mainly due to the influence of the electrolyte on the membrane properties, which is fixed by the membrane soaking. A quantitative correlation has been established between the solvent and solute transfer and the hydratio n number of the membrane counterion. In presence of electrolyte, the saccharide mass transfer increased but the impact of the presence of electrolyte is much less than the one of membrane soaking. However, in this case, a relationship has been also established between the increase of the saccharide mass transfer and the cation hydration state.

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Section: Influence Of the Membrane Soakingmentioning

confidence: 99%

Section: Influence Of the Membrane Soakingmentioning

confidence: 99%

Influence of the ionic composition on the diffusion mass transfer of saccharides through a cation-exchange membrane

Galier¹,

Savignac²,

Balmann³

2013

Separation and Purification Technology

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“…Water transport through ion-exchange membranes has been addressed in the literature both experimentally [3][4][5] and theoretically [6][7][8]. Four mechanisms are often considered to cause water transport: I.…”

Section: Introductionmentioning

confidence: 99%

Nernst-Planck transport theory for (reverse) electrodialysis: II. Effect of water transport through ion-exchange membranes

Tedesco¹,

Hamelers²,

Biesheuvel³

2017

Journal of Membrane Science

140

121

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Transport of water through ion-exchange membranes is of importance both for electrodialysis (ED) and reverse electrodialysis (RED). In this work, we extend our previous theory [J. Membrane Sci., 510, (2016) 370-381] and include water transport in a two-dimensional model for (R)ED. Following a Maxwell-Stefan (MS) approach, ions in the membrane have friction with the water, pore walls, and one another. We show that when ion-ion friction is neglected, the MS-approach is equivalent to the hydrodynamic theory of hindered transport, for instance applied to nanofiltration. After validation against experimental data from literature for ED and RED, the model is used to analyze single-pass seawater ED, and RED with highly concentrated solutions. In the model, fluxes and velocities of water and ions in the membranes are self-consistently calculated as function of the driving forces. We investigate the influence of water and coion leakage under different operational conditions.

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“…Membrane's water uptake is a key factor, since water is necessary to grant a good proton conductivity. 1,39,40 However, a high water uptake like that measured for the thinnest membrane can lead to a high methanol crossover, poor mechanical stability (especially at high temperature) and a possible flooding of the cell with detrimental effect on the performances. Figure 4A shows polarization and power density curves recorded with a membrane reticulated for 30 minutes at different operating temperatures (ie, 30, 50, and 70 C), while in Figure 4B, a comparison between polarization and power density curves recorded by using a thin membrane (ie, reticulation time 30 seconds) and a thick membrane (ie, reticulation time 30 minutes) is reported.…”

Section: Membrane Liquid Uptakementioning

confidence: 99%

Methanol and proton transport through chitosan‐phosphotungstic acid membranes for direct methanol fuel cell

et al. 2020

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Composite chitosan-phosphotungstic acid membranes were synthesized by ionotropic gelation. Their liquid uptake is higher for thin membranes (23 ± 2 μm), while it is lower ($70%) for thicker membranes (50-70 μm). Polarization curves recorded using single module fuel cell at 70 C allowed to estimate a peak power density of 60 mW cm −2 by using 1 M as methanol and low Pt and Pt/Ru loadings (0.5 and 3 mg cm −2) at the cathode and at the anode, respectively. Electrochemical impedance spectroscopy was used to estimate the membrane conductivity and to model the electrochemical behavior of methanol electrooxidation inside the fuel cell revealing a two-step mechanism mainly responsible of overall kinetic losses. Transport of methanol inside the membrane was studied by potentiostatic measurements, allowing to estimate a methanol diffusivity of 3.6 × 10 −6 cm 2 s −1 .

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Water uptake and salt transport through Nafion cation-exchange membranes with different thicknesses

Cited by 64 publications

References 39 publications

Influence of the ionic composition on the diffusion mass transfer of saccharides through a cation-exchange membrane

Influence of the ionic composition on the diffusion mass transfer of saccharides through a cation-exchange membrane

Nernst-Planck transport theory for (reverse) electrodialysis: II. Effect of water transport through ion-exchange membranes

Methanol and proton transport through chitosan‐phosphotungstic acid membranes for direct methanol fuel cell

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