The effect of temperature on the swelling of montmorillonite

Clay Minerals ◽  
1993 ◽  
Vol 28 (1) ◽  
pp. 25-31 ◽  
Author(s):  
F. Zhang ◽  
Z. Z. Zhang ◽  
P. F. Low ◽  
C. B. Roth
Keyword(s):  
Double Layer ◽  
Electric Double Layer ◽  
Swelling Pressure ◽  
Interlayer Spacing ◽  
Effect Of Temperature ◽  
Thermal Breakdown ◽  
Mass Ratio ◽  
Interlayer Region ◽  
Double Layer Theory ◽  
The Relationship

AbstractThe effect of temperature on the swelling of clay was studied by determining (1) the relation between the interlayer spacing, λ, and the swelling pressure,Π, at different values of the temperature, T, using the method of Viani et al. (1983) as modified by Wu et al. (1989); (2) the relation between λ and T at different values of Π; and (3) the relationship between Π and mw/mc, the mass ratio of water to clay, at different values of T using the method of Low (1980). The results showed that λ was essentially independent of T but that mw/mc decreased slightly with T at any value of Π. Such results are not consistent with electric double-layer theory. Therefore, it was concluded that the decrease in mw/mc with increasing T was due primarily to the thermal breakdown and consequent loss of water from the larger pores outside of the interlayer region.

New equations for swelling characteristics of bentonite-based buffer materials

2003 ◽  
Vol 40 (2) ◽  
pp. 460-475 ◽  
Author(s):  
Hideo Komine ◽  
Nobuhide Ogata
Keyword(s):  
Double Layer ◽  
Nuclear Waste ◽  
Van Der Waals ◽  
Swelling Pressure ◽  
Van Der Waals Force ◽  
Diffuse Double Layer ◽  
Mass Ratio ◽  
Compacted Bentonite ◽  
Buffer Material ◽  
Swelling Characteristics

Compacted bentonite and sand–bentonite mixtures are attracting greater attention as buffer material for repositories of high-level nuclear waste. This buffer material is expected to fill up the space between the canisters containing the waste and the surrounding ground by swelling. To produce the specifications, such as dry density, sand–bentonite mass ratio, and dimensions, of the buffer material, the swelling characteristics of compacted bentonite and sand–bentonite mixtures must be evaluated quantitatively. New equations for evaluating the swelling behavior of compacted bentonite and sand–bentonite mixtures are presented that can accommodate the influences of the sand–bentonite mass ratio and the exchangeable-cation composition of bentonite. The new method for predicting swelling characteristics is presented by combining the new equations with the theoretical equations of the Gouy–Chapman diffuse double layer theory and of the van der Waals force, which can evaluate the repulsive and attractive forces of montmorillonite mineral (i.e., the swelling clay mineral in bentonite). Furthermore, the applicability of the new prediction method has been confirmed by comparing the predicted results with laboratory test results on the swelling deformation and swelling pressure of compacted bentonites and sand–bentonite mixtures.Key words: bentonite, diffuse double layer theory, van der Waals force, nuclear waste disposal, swelling deformation, swelling pressure.

Electric Double Layer at the Rutile (110) Surface. 4. Effect of Temperature and pH on the Adsorption and Dynamics of Ions

2013 ◽  
Vol 117 (44) ◽  
pp. 22852-22866 ◽  
Author(s):  
M. Předota ◽  
M. L. Machesky ◽  
D. J. Wesolowski ◽  
P. T. Cummings
Keyword(s):  
Double Layer ◽  
Electric Double Layer ◽  
Effect Of Temperature

Prediction of the hydraulic conductivity of clays using the electric double layer theory

1999 ◽  
Vol 36 (5) ◽  
pp. 783-792 ◽  
Author(s):  
Gopal Achari ◽  
R C Joshi ◽  
L R Bentley ◽  
S Chatterji
Keyword(s):  
Hydraulic Conductivity ◽  
Double Layer ◽  
Electric Double Layer ◽  
Layer Model ◽  
Clay Liners ◽  
Overburden Pressure ◽  
Clay Particles ◽  
Concentration Of Ions ◽  
Double Layer Model ◽  
Double Layer Theory

A model to predict the hydraulic conductivity of consolidated clay, simulating clay liners compacted wet of optimum, is presented. The concept that clays exist as clusters and the electrical double layer theory are used to predict the hydraulic conductivity of clays for permeants of known composition. The model relates the physical properties of clays, such as its surface area, with the overburden pressure and the concentration of ions in the permeant. The model can be used to predict the hydraulic conductivity of bentonitic clays with monovalent as well as divalent exchangeable cations. The model is valid within the range of applicability of the Gouy-Chapman electric double layer theory. The variation in the number of clay particles per cluster with the consolidation pressure and concentration of ions in the permeant has been discussed. The model has been calibrated and verified using published experimental data. However, the model in its present form is valid only for homoionic clays and permeants with the same valency. With an increase in concentration of ions in the permeant, the precision of the model has been found to decrease. Key words: clay, clusters, hydraulic conductivity, double layer, model, permeant, concentration.

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