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Forces Between Suspended Bentonite Particles

Published online by Cambridge University Press:  01 January 2024

H. van Olphen
H. van Olphen*
Affiliation:
Shell Development Company, Houston, Texas, USA
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Abstract

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Purified sodium bentonite suspensions in water display rigidity at concentrations as low as about 2 percent. On addition of NaCl the yield stress decreases, but beyond about 5 meq/ liter of NaCl it increases. The same is true for the relative viscosities and the sediment volumes of more dilute suspensions. This is interpreted as a flocculation-deflocculation-floccu-lation sequence. The paradoxical phenomenon of flocculation of the clean suspensions is explained by the concept of positive edge charge of the clay plates, allowing positive edge to negative flat-surface flocculation.

Both the purified and the salt-flocculated gels show Bingham flow behavior. When Good-eve’s analysis of Bingham flow is applied, the linking force between the clay plates in the pure gels is computed at about 10−4 dyne.

The salt-flocculated gels show thixotropic hysteresis, whereas the pure gels set immediately after stirring. This means that there is no energy barrier for gelation in the pure gels, which is in line with the proposed mechanism of association due to Coulomb attraction. In the salt-flocculated gels there must be an energy barrier causing thixotropic hysteresis. This might be expected from the summation of residual double-layer repulsion and van der Waals attraction. Considering thixotropic stiffening as slow coagulation, the height of the energy barrier could be calculated from the thixotropic increase of the modulus of elasticity with time after previous shear breakdown of the structure. The reasonable value of 7 kT was found for the height of the energy barrier of a gel containing 30 meq/liter of NaCl.

Type
Article
Information
Clays and Clay Minerals (National Conference on Clays and Clay Minerals) , Volume 4 , February 1955 , pp. 204 - 224
Copyright
Copyright © The Clay Minerals Society 1955

Footnotes

Publication No. 62, Shell Development Company, Exploration and Production Research Division, Houston, Texas.

References

Bondi, A., 1953, Particle kinetics in gels: Proc. Second Intern. Congress on Rheology, Oxford, p. 274–283.Google Scholar
Call, F., 1953, Preparation of dry clay-gels by freeze-drying: Nature, v. 172, p. 126.CrossRefGoogle Scholar
Eggleton, A. E. J., and Puddington, I. E., 1954, The effect of temperature on suspensions of glass beads in toluene containing various percentages of water; Can. J. Chem., v. 32, p. 86–93.CrossRefGoogle Scholar
Fahn, R., Weiss, Armin, and Hofmann, U., 1953, Über die Thixotropie bei Tonen: Berichte der Deutschen Keramischen Gesellschaft, v. 30, p. 21–25.Google Scholar
Goodeve, C. F., 1939, A general theory of thixotropy and viscosity: Faraday Soc. Trans., v. 35, p. 342–358.CrossRefGoogle Scholar
Goodeve, C. F., 1948, The mechanism of thixotropic and plastic flow: Proc. Intern. Rheological Congress, Holland.Google Scholar
Kahn, Allan, and Lewis, D. R., 1954, The size of sodium montmorillonite particles in suspension from electro-optical birefringence studies: J. Phys. Chem., v. 58, p. 801–804; Shell EPR Pub. 44.CrossRefGoogle Scholar
Kruyt, H. R., 1952, Colloid Science, Part I, Elsevier Publishing Co., New York, 389 p.Google Scholar
van Oiphen, H., 1950, Pumpability, rheological properties, and viscometry of drilling fluids: J. Inst. Petroleum, v. 36, p. 223–234.Google Scholar
van Oiphen, H., 1950a, Stabilization of montmorillonite sols by chemical treatment: Rec. Trav. Chim. Pays Bas., v. 69, p. 1308–1322.CrossRefGoogle Scholar
van Oiphen, H., 1951, Chemical treatment of drilling fluids: Thesis, Delft, 137 p.Google Scholar
van Oiphen, H., 1951a, The size and shape factor in colloidal systems: A general discussion, Faraday Soc., v. 11, p. 82–84.Google Scholar
van Oiphen, H., 1954, Inlerlayer forces in bentonite: in Clays and clay minerals, Nat'l. Acad. Sci.—Nat'l. Res. Council Pub. 327, p. 418–437; Shell EPR Pub. 40.Google Scholar
Verwey, E. J. W., and Overbeek, J. Th. G., 1948, Theory of the stability of lyophobic colloids: Elsevier Publishing Co., New York, 205 p.Google Scholar
Weiss, Armin, Fahn, R., and Hofmann, U., 1952, Nachweis der Gerüststruktur in thixotropen Gelen: Naturwiss., v. 39, p. 351–352.CrossRefGoogle Scholar
Alexander, A. E., and Johnson, P., 1949, Colloid science, v. 2: Oxford University Press, 837 p.Google Scholar
Hauser, E. A., 1929, Ueber die Thixotropie von Dispersionen geringer Konzentration: Koll. Z., v. 48, p. 57–61.CrossRefGoogle Scholar
Hauser, E. A., 1956, Report on the Fourth National Clay Conference, October 10-13, 1955, at Pennsylvania State University: Koli. Z., v. 145, p. 46–48.CrossRefGoogle Scholar
Hauser, E. A., and Reed, C. E., 1937, Studies in thixotropy II, The thixotropic behavior and structure of bentonite: J. Phys. Chem., v. 41, p. 910–934.CrossRefGoogle Scholar
Hofmann, Ulrich, 1952, Neue Erkenntnisse auf dem Gebiete der Thixotropie, insbesondere bei tonhaltigen Gelen: Koli. Z., v. 125, p. 86–99.CrossRefGoogle Scholar
Kruyt, H. R., 1952, Colloid science, Part I: Elsevier Publishing Co., New York, 389 p.Google Scholar
van Olphen, H., 1950, Stabilization of montmorillonite sols by chemical treatment: Rec. Trav. Chim. Pays Bas, v. 69, 1313-1322.Google Scholar
Verwey, E. J. W., and Overbeek, J. Th. G., 1948, Theory of the stability of lyophobic colloids: Elsevier Publishing Co., New York, 205 p.Google Scholar