HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Rhoads, F. M. Articles by Nash, V. E. Search for Related Content PubMed Articles by Rhoads, F. M. Articles by Nash, V. E. GeoRef GeoRef Citation Agricola Articles by Rhoads, F. M. Articles by Nash, V. E.

Relationships Among Electrochemical Properties, Type of Colloid and Adsorbed Cations of Soil and Mineral Colloidal Suspensions¹

ABSTRACT

Potentiometric cation activities, electrophoretic mobilities and specific conductance at variable frequencies were determined on suspensions of five reference clay minerals and five soil clays. The objectives of this work are: (i) to determine the relationship between clay mineralogy and specific conductance with a variable frequency power source, (ii) to determine the interrelationship among the various electrochemical measurements, and (iii) to study the effect of different exchangeable cations on the electrochemical properties.

Montmorillonitic minerals with a charge deficiency in the octahedral layer showed the greatest change in specific conductance with increasing frequency. Vermiculite, on the other hand, showed less evidence of a change in conductance with frequency; illite showed no change. This was taken to indicate that a greater proportion of the exchangeable cations on montmorillonite was in the Stern layer whereas the cations on the higher surface charge density clays were distributed between the Gouy and the chemisorbed layer.

A Stern layer on the montmorillonite minerals developed to a greater extent for monovalent cations than divalent. The divalent cations were apparently located between the unit layers of the mineral and did not conduct electric current even at high frequencies.

¹ Contribution from Dep. of Agron., Mississippi Agr. Exp. Sta. no. 1536. Presented before Div. S-2, Soil Sci. Soc. Amer., Aug. 24, 1966, Stillwater, Okla.

² Formerly graduate student, now Assistant Soil Chemist, North Florida Exp. Sta. and Associate Agronomist, respectively.

Received for publication March 20, 1967. Accepted for publication August 3, 1967.