Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-24T02:23:55.530Z Has data issue: false hasContentIssue false
  • English
  • Français

A Direct Procedure for Determining the number of Plates in Tactoids of Smectites: The Na/Ca-Montmorillonite Case

Published online by Cambridge University Press:  01 July 2024

I. Shomer  and
U. Mingelgrin
I. Shomer
Affiliation:
Institute of Soils and Water, Agricultural Research Organization, The Volcani Center, POB 6, Bet Dagan, Israel
U. Mingelgrin
Affiliation:
Institute of Soils and Water, Agricultural Research Organization, The Volcani Center, POB 6, Bet Dagan, Israel
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The dispersion of clays is of great importance in determining various soil properties such as hydraulic conductivity. A procedure which involves fixing followed by embedding of clay particles in an epoxy resin is described. This procedure enables the observation of cross sections of clay tactoids under a transmittance electron microscope, and the determination of the number of plates per tactoid. The use of the procedure for the determination of the relation between the exchangeable sodium percentage (ESP) and tactoid size in suspensions of a Na/Ca bentonite system is presented. It was demonstrated that even at ESP 5 significant dispersion already occurs, the average number of plates per tactoid being 6.6 as compared to 16.1 at ESP 0.

Резюме

Резюме

Дисперсия глин имеет огромное значение при определении различных свойств почвы, таких как гидравлическая проводимость. Описывается процедура, которая включает фиксирование и внесение глинистых частиц в эпоксидную смолу. Эта процедура позволяет наблюдать профиль глинистых тактоидов под просвечивающим электронным микроскопом и определять число пластин на тектоид. Описывается испльзование процедуры для определения отношения между обменным количеством натрия /ОКН/ и размером тектоида в суспензиях бентонитовой системы Na/Ca. Было показано, что даже при OКН=5 уже наблюдается значительная дисперсия, среднее число пластин на тактоид достигает 6,6 по сравнению с 16,1 при ОКН=0.

Kurzreferat

Kurzreferat

Die Dispersion von Tonerden ist von großer Wichtigkeit bei der Bestimmung verschiedener Eigenschaften wie z.B. hydraulische Leitfähigkeit. Eine Prozedur, welche Befestigung und nachfolgendes Einbetten von Ton partikeln in ein Epoxyharz umfasst, wird beschrieben. Dieses Verfahren macht die Observierung von Querschnitten von Tontaktoiden unter einem Trans parenzelektronenmikroskop und die Bestimmung der Anzahl von Tafeln per Taktoid möglich. Der Gebrauch dieser Prozedur für die Bestimmung des Verhältnisses zwischen dem austauschbaren-Natrium-Prozentsatz (ESP) und der Taktoid größe in Suspensionen eines Na/Ca Bentoniten wird presentiert.Es wurde demonstriert, daß sogar bei einem ESP- Wert von 5, schon Dispersion stattfindet. Die durchschnittliche Anzahl von Tafeln per Taktoid ist 6,6 verglichen mit 16,1 für einen ESP Wert von 0.

Keywords

BentoniteConductivityDispersionHydraulicSmectiteTactoid
Type
Research Article
Information
Clays and Clay Minerals , Volume 26 , Issue 2 , April 1978 , pp. 135 - 138
Copyright
Copyright © 1978, The Clay Minerals Society

Footnotes

*

Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. 1977 Series. No. 199-E.

References

Albert, J. T. and Harter, R. D. (1973) Adsorption of lysozyme and ovalbumin by clay: effect of clay suspension pH and clay mineral type: Soil Sci. 115, 130–136.CrossRefGoogle Scholar
Banin, A. and Lahav, N. (1968) Particle size and optical properties of montmorillonite in suspension: Israel J. Chem. 6, 235–250.CrossRefGoogle Scholar
Dufey, J. E., Banin, A., Laudelout, H. and Chen, Y. (1976) Particle shape and sodium self diffusion coefficient in mixed Na-Ca montmorillonite: Soil Sci. Soc. Am. J. 40, 310–314.CrossRefGoogle Scholar
Russo, D. and Bresler, E. (1977) Analysis of the saturated-unsaturated hydraulic conductivity in a mixed Na-Ca soil system: Soil Sci. Soc. Am. J. 41, 706–710.CrossRefGoogle Scholar
Shainbert, I. and Kaiserman, A. (1969) Kinetics of the formation and breakdown of Ca-montmorillonite tactoids: Soil Sci. Soc. Am. Proc. 33, 547–551.CrossRefGoogle Scholar
Shainberg, I. and Otoh, H. (1968) Size and shape of montmorillonite particles saturated with Na/Ca ions (inferred from viscosity and optical measurements): Israel J. Chem. 6, 251–259.CrossRefGoogle Scholar
Spurr, A. R. (1969) A low-viscosity epoxy resin embedding medium for electron microscopy: J. Ultrastruct. Res. 26, 31–43.CrossRefGoogle ScholarPubMed
Suito, E., Arakaua, M. and Yoshida, T. (1969) Electron microscopic observation of the layer of organo-montmorillonite: Proc. Int. Clay Conf., Tokyo, Japan, pp. 757–763.Google Scholar
Tchoubaric, C., Rautureau, M., Clinard, C. and Rogot, J. P. (1973) Technique d'inclusion appliquée a l'étude des silicates lamellaires et fibreaux: J. Micros. (Paris) 18, 147–154.Google Scholar