Journal Article

FZJ-2017-04559

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Spectral induced polarization of Na-montmorillonite dispersions

Leroy, P. (Corresponding author) ; Weigand, M. ; Mériguet, G. ; Zimmermann, E.FZJ* ; Tournassat, C. ; Fagerlund, F. ; Kemna, A. ; Huisman, J. A.FZJ*

2017
Elsevier Amsterdam [u.a.]

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Please use a persistent id in citations: doi:10.1016/j.jcis.2017.06.071

Abstract: Montmorillonite (Mt) clays have a high specific surface area and surface charge, which confer themremarkable adsorption properties. Nevertheless, their electrochemical and aggregation behavior arenot completely elucidated because of the complexity of their microstructural and interfacial properties.In this work, the conductive and dispersive properties of Na-Mt suspensions of weight fractions 0.5–5.2%were investigated for the first time using the spectral induced polarization method. A four-electrode systemwas used to reduce errors introduced by electrode polarization and contact resistances. Complexconductivity spectra in the low-frequency range of 0.1 Hz to 45 kHz were successfully described usinga triple layer model of the basal surface of Mt and a complex conductivity model that considers conductionof the diffuse layer and polarization of the Stern layer. Aggregate size distributions were inferredfrom inverted relaxation time distributions. We found that the negative and permanent surface chargeof the basal plane of Na-Mt controls its quadrature (imaginary) conductivity, which is not very sensitiveto pH and salinity (NaCl) in the 100 Hz to 45 kHz frequency range. For lower frequencies, the suddenincrease of the quadrature conductivity at the highest salinities was explained by considering coagulationof Na-Mt particles.

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Contributing Institute(s):

1. Agrosphäre (IBG-3)
2. Zentralinstitut für Elektronik (ZEA-2)

Research Program(s):

1. 255 - Terrestrial Systems: From Observation to Prediction (POF3-255) (POF3-255)

Appears in the scientific report 2017

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Database coverage:
; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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