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Ion transport through electrolyte/polyelectrolyte multi-layers.

Femmer R, Mani A, Wessling M - Sci Rep (2015)

Bottom Line: Ion transport of multi-ionic solutions through layered electrolyte and polyelectrolyte structures are relevant in a large variety of technical systems such as micro and nanofluidic devices, sensors, batteries and large desalination process systems.EnPEn can robustly capture ion transport in sub-millimeter architectures with submicron polyelectrolyte layers.We proof the strength of EnPEn for three yet unsolved architectures: (a) selective Na over Ca transport in surface modified ion selective membranes, (b) ion transport and water splitting in bipolar membranes and (c) transport of weak electrolytes.

View Article: PubMed Central - PubMed

Affiliation: AVT Chemical Process Engineering, RWTH Aachen University, Turmstr. 46, 52064 Aachen, Germany.

ABSTRACT
Ion transport of multi-ionic solutions through layered electrolyte and polyelectrolyte structures are relevant in a large variety of technical systems such as micro and nanofluidic devices, sensors, batteries and large desalination process systems. We report a new direct numerical simulation model coined EnPEn: it allows to solve a set of first principle equations to predict for multiple ions their concentration and electrical potential profiles in electro-chemically complex architectures of n layered electrolytes E and n polyelectrolytes PE. EnPEn can robustly capture ion transport in sub-millimeter architectures with submicron polyelectrolyte layers. We proof the strength of EnPEn for three yet unsolved architectures: (a) selective Na over Ca transport in surface modified ion selective membranes, (b) ion transport and water splitting in bipolar membranes and (c) transport of weak electrolytes.

No MeSH data available.


Related in: MedlinePlus

Current-voltage behaviour of a weak 1-1 salt with pK = 4.At V = 40 Vth, decreasing pH in the feed shifts the dissociation equilibrium towards the anion, which decreases overall resistance. The transport numbers are sampled at the membrane interface.
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f6: Current-voltage behaviour of a weak 1-1 salt with pK = 4.At V = 40 Vth, decreasing pH in the feed shifts the dissociation equilibrium towards the anion, which decreases overall resistance. The transport numbers are sampled at the membrane interface.

Mentions: Figure 6 shows the current voltage curve featuring multiple resistances. The first limiting current density can be attributed to the depletion of the salt on the feed side of the membrane. Once the voltage reaches approximately 20 Vth or 0.5 V, the additional flux of H+ and OH− ions leads to a lowered resistance. This is confirmed by the increase in transport number of OH− sampled at the membrane interface. At higher potentials, both counter-ion transport numbers approach roughly 0.5.


Ion transport through electrolyte/polyelectrolyte multi-layers.

Femmer R, Mani A, Wessling M - Sci Rep (2015)

Current-voltage behaviour of a weak 1-1 salt with pK = 4.At V = 40 Vth, decreasing pH in the feed shifts the dissociation equilibrium towards the anion, which decreases overall resistance. The transport numbers are sampled at the membrane interface.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4481379&req=5

f6: Current-voltage behaviour of a weak 1-1 salt with pK = 4.At V = 40 Vth, decreasing pH in the feed shifts the dissociation equilibrium towards the anion, which decreases overall resistance. The transport numbers are sampled at the membrane interface.
Mentions: Figure 6 shows the current voltage curve featuring multiple resistances. The first limiting current density can be attributed to the depletion of the salt on the feed side of the membrane. Once the voltage reaches approximately 20 Vth or 0.5 V, the additional flux of H+ and OH− ions leads to a lowered resistance. This is confirmed by the increase in transport number of OH− sampled at the membrane interface. At higher potentials, both counter-ion transport numbers approach roughly 0.5.

Bottom Line: Ion transport of multi-ionic solutions through layered electrolyte and polyelectrolyte structures are relevant in a large variety of technical systems such as micro and nanofluidic devices, sensors, batteries and large desalination process systems.EnPEn can robustly capture ion transport in sub-millimeter architectures with submicron polyelectrolyte layers.We proof the strength of EnPEn for three yet unsolved architectures: (a) selective Na over Ca transport in surface modified ion selective membranes, (b) ion transport and water splitting in bipolar membranes and (c) transport of weak electrolytes.

View Article: PubMed Central - PubMed

Affiliation: AVT Chemical Process Engineering, RWTH Aachen University, Turmstr. 46, 52064 Aachen, Germany.

ABSTRACT
Ion transport of multi-ionic solutions through layered electrolyte and polyelectrolyte structures are relevant in a large variety of technical systems such as micro and nanofluidic devices, sensors, batteries and large desalination process systems. We report a new direct numerical simulation model coined EnPEn: it allows to solve a set of first principle equations to predict for multiple ions their concentration and electrical potential profiles in electro-chemically complex architectures of n layered electrolytes E and n polyelectrolytes PE. EnPEn can robustly capture ion transport in sub-millimeter architectures with submicron polyelectrolyte layers. We proof the strength of EnPEn for three yet unsolved architectures: (a) selective Na over Ca transport in surface modified ion selective membranes, (b) ion transport and water splitting in bipolar membranes and (c) transport of weak electrolytes.

No MeSH data available.


Related in: MedlinePlus