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Current‐Induced Ion Concentration Polarization at a Perfect Ion‐Exchange Patch in an Infinite Insulating Wall
Author(s) -
Bondarenko Mykola P.,
Bruening Merlin L.,
Yaroshchuk Andriy E.
Publication year - 2020
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201902068
Subject(s) - ion , electric field , dimensionless quantity , polarization (electrochemistry) , materials science , electric potential , electrode , voltage , chemistry , molecular physics , analytical chemistry (journal) , mechanics , computational physics , physics , chromatography , organic chemistry , quantum mechanics
This research examines, theoretically, the ion concentration polarization, ion fluxes, and electrostatic fields near an ion‐exchange patch in the wall of an electrified fluidic channel. These phenomena are important in related microfluidic ion‐preconcentration systems. Under an electric field, counter ions enter the ion‐exchange patch at one side and leave at the other, with salt depletion occurring near the entrance and accumulation near the exit. The high patch conductivity and the concentration profiles lead to local electric field perturbations that may facilitate preconcentration. This study includes analytical expressions of ion concentrations and electrochemical potentials at small to moderate electric fields, as well as numerical simulations. Additionally, a simple matrix of polynomial coefficients (obtained via fitting of numerical data) enables analytical calculation of the two‐dimensional concentration profiles at all electric fields within the range investigated in the numerical simulations. This is possible because a single dimensionless parameter controls this problem.