Mathematical model of current-polarized ionophore-based ion-selective membranes: Large current chronopotentiometry

Justin M. Zook, Richard P. Buck, R. Gyurcsányi, Erno Lindnera

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

The properties of ionophore-based ion-selective membranes were investigated theoretically and experimentally for the first time in large-current chronopotentiometric experiments. In these experiments, when either the free ionophore or the ion-ionophore complex concentration drops to zero at one of the membrane boundaries, a characteristic drop in voltage (breakpoint) appears in the chronopotentiometric transients at a transition time τ. Based on a mathematical model of current polarized membranes, theoretical equations were derived and tested. These equations describe the correlation between the transition time τ and the concentration of free ionophore, the concentration of ion-ionophore complex, and the diffusion coefficients of species in the membrane. The simulated concentration profiles correlated well with concentration profiles recorded experimentally prior to the transition time using spectroelectrochemical microscopy (SpECM). Diffusion coefficients calculated from (i) the transition times, (ii) curve fitting, and (iii) the initial ohmic resistance of the studied membranes were also compared. Similar to chronoamperometry, the chronopotentiometric transition times provided possibilities for assessing the loss of free ionophore and lipophilic anion from cation selective electrode membranes during continuous use.

Original languageEnglish
Pages (from-to)259-269
Number of pages11
JournalElectroanalysis
Volume20
Issue number3
DOIs
Publication statusPublished - Feb 2008

Fingerprint

Ion selective membranes
Ionophores
Mathematical models
Membranes
Ions
Chronoamperometry
Acoustic impedance
Curve fitting
Anions
Cations
Microscopic examination
Negative ions
Positive ions
Experiments
Electrodes
Electric potential

Keywords

  • Chronopotentiometry
  • Concentration profiles
  • Current polarization
  • Ion selective electrode
  • Mathematical membrane model
  • Potential transients

ASJC Scopus subject areas

  • Analytical Chemistry
  • Electrochemistry

Cite this

Mathematical model of current-polarized ionophore-based ion-selective membranes : Large current chronopotentiometry. / Zook, Justin M.; Buck, Richard P.; Gyurcsányi, R.; Lindnera, Erno.

In: Electroanalysis, Vol. 20, No. 3, 02.2008, p. 259-269.

Research output: Contribution to journalArticle

@article{cb36891c4026481d816d8ae07700d9ad,
title = "Mathematical model of current-polarized ionophore-based ion-selective membranes: Large current chronopotentiometry",
abstract = "The properties of ionophore-based ion-selective membranes were investigated theoretically and experimentally for the first time in large-current chronopotentiometric experiments. In these experiments, when either the free ionophore or the ion-ionophore complex concentration drops to zero at one of the membrane boundaries, a characteristic drop in voltage (breakpoint) appears in the chronopotentiometric transients at a transition time τ. Based on a mathematical model of current polarized membranes, theoretical equations were derived and tested. These equations describe the correlation between the transition time τ and the concentration of free ionophore, the concentration of ion-ionophore complex, and the diffusion coefficients of species in the membrane. The simulated concentration profiles correlated well with concentration profiles recorded experimentally prior to the transition time using spectroelectrochemical microscopy (SpECM). Diffusion coefficients calculated from (i) the transition times, (ii) curve fitting, and (iii) the initial ohmic resistance of the studied membranes were also compared. Similar to chronoamperometry, the chronopotentiometric transition times provided possibilities for assessing the loss of free ionophore and lipophilic anion from cation selective electrode membranes during continuous use.",
keywords = "Chronopotentiometry, Concentration profiles, Current polarization, Ion selective electrode, Mathematical membrane model, Potential transients",
author = "Zook, {Justin M.} and Buck, {Richard P.} and R. Gyurcs{\'a}nyi and Erno Lindnera",
year = "2008",
month = "2",
doi = "10.1002/elan.200704052",
language = "English",
volume = "20",
pages = "259--269",
journal = "Electroanalysis",
issn = "1040-0397",
publisher = "Wiley-VCH Verlag",
number = "3",

}

TY - JOUR

T1 - Mathematical model of current-polarized ionophore-based ion-selective membranes

T2 - Large current chronopotentiometry

AU - Zook, Justin M.

AU - Buck, Richard P.

AU - Gyurcsányi, R.

AU - Lindnera, Erno

PY - 2008/2

Y1 - 2008/2

N2 - The properties of ionophore-based ion-selective membranes were investigated theoretically and experimentally for the first time in large-current chronopotentiometric experiments. In these experiments, when either the free ionophore or the ion-ionophore complex concentration drops to zero at one of the membrane boundaries, a characteristic drop in voltage (breakpoint) appears in the chronopotentiometric transients at a transition time τ. Based on a mathematical model of current polarized membranes, theoretical equations were derived and tested. These equations describe the correlation between the transition time τ and the concentration of free ionophore, the concentration of ion-ionophore complex, and the diffusion coefficients of species in the membrane. The simulated concentration profiles correlated well with concentration profiles recorded experimentally prior to the transition time using spectroelectrochemical microscopy (SpECM). Diffusion coefficients calculated from (i) the transition times, (ii) curve fitting, and (iii) the initial ohmic resistance of the studied membranes were also compared. Similar to chronoamperometry, the chronopotentiometric transition times provided possibilities for assessing the loss of free ionophore and lipophilic anion from cation selective electrode membranes during continuous use.

AB - The properties of ionophore-based ion-selective membranes were investigated theoretically and experimentally for the first time in large-current chronopotentiometric experiments. In these experiments, when either the free ionophore or the ion-ionophore complex concentration drops to zero at one of the membrane boundaries, a characteristic drop in voltage (breakpoint) appears in the chronopotentiometric transients at a transition time τ. Based on a mathematical model of current polarized membranes, theoretical equations were derived and tested. These equations describe the correlation between the transition time τ and the concentration of free ionophore, the concentration of ion-ionophore complex, and the diffusion coefficients of species in the membrane. The simulated concentration profiles correlated well with concentration profiles recorded experimentally prior to the transition time using spectroelectrochemical microscopy (SpECM). Diffusion coefficients calculated from (i) the transition times, (ii) curve fitting, and (iii) the initial ohmic resistance of the studied membranes were also compared. Similar to chronoamperometry, the chronopotentiometric transition times provided possibilities for assessing the loss of free ionophore and lipophilic anion from cation selective electrode membranes during continuous use.

KW - Chronopotentiometry

KW - Concentration profiles

KW - Current polarization

KW - Ion selective electrode

KW - Mathematical membrane model

KW - Potential transients

UR - http://www.scopus.com/inward/record.url?scp=42449090605&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=42449090605&partnerID=8YFLogxK

U2 - 10.1002/elan.200704052

DO - 10.1002/elan.200704052

M3 - Article

AN - SCOPUS:42449090605

VL - 20

SP - 259

EP - 269

JO - Electroanalysis

JF - Electroanalysis

SN - 1040-0397

IS - 3

ER -