Correcting the polarization effect in very low frequency dielectric spectroscopy

Document Type

Article

Publication Date

9-18-2009

Abstract

Polarization impedance appears at the interface between electrodes and ionic solutions and is a major source of errors in dielectric spectroscopy measurements. This work presents a simple, robust and automated methodology for measuring and analysing the polarization impedance of non-dispersive electrolytes, with a focus on the very low frequency domain from 1 Hz and up. The accuracy of the method is demonstrated by comparing the corrected dielectric permittivity and conductivity of various electrolytes either with their nominal values or with measurements taken with other high precision measuring devices. The dependence of the polarization impedance on several parameters, such as ionic concentration, applied voltage and separation distance between the electrodes, is also presented. For colloidal suspensions, it is argued that a modified protocol of the substitution method is needed due to several shortcomings occurring only in the very low frequency domain. Such a protocol is presented and tested on suspensions of live E. coli cells. As opposed to most of the existing methodologies for polarization removal, the proposed protocol makes no assumptions on the behaviour of the polarization impedance. This could potentially lead to the quantitative resolution of the α-dispersion of live cells in suspension. © 2009 IOP Publishing Ltd.

Identifier

70249137674 (Scopus)

Publication Title

Journal of Physics D Applied Physics

External Full Text Location

https://doi.org/10.1088/0022-3727/42/17/175505

e-ISSN

13616463

ISSN

00223727

Issue

17

Volume

42

Grant

0547427

Fund Ref

National Science Foundation

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