Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-25T07:02:13.868Z Has data issue: false hasContentIssue false
  • English
  • Français

The Sol Concentration Effect in n-Butylammonium Vermiculite Swelling

Published online by Cambridge University Press:  28 February 2024

G. D. Williams ,
K. R. Moody ,
M. V. Smalley  and
S. M. King
G. D. Williams
Affiliation:
Physical Chemistry Laboratory, South Parks Road, Oxford, OX1 3QZ, United Kingdom
K. R. Moody
Affiliation:
Physical Chemistry Laboratory, South Parks Road, Oxford, OX1 3QZ, United Kingdom
M. V. Smalley*
Affiliation:
Polymer Phasing Project, ERATO, JRDC, Keihanna Plaza 1–7 Hikari-dai, Seika-cho, Kyoto 619-02, Japan
S. M. King
Affiliation:
ISIS Science Division, Rutherford Appleton Laboratory Chilton, Didcot, Oxon, OX11 OQX, United Kingdom
*
1To whom correspondence should be addressed.
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 swelling of n-butylammonium vermiculite in water was investigated as a function of the sol concentration (r), the salt concentration (c) and the temperature (T).

The interlayer spacing in the gel phase was investigated as a function of r and c by neutron diffraction and by laboratory experiments which measured how many times its own volume a crystal would absorb. The salt concentration was found to be the stronger variable with the interlayer spacing decreasing proportional to c0.5, which is consistent with previous results and with the Coulombic attraction theory. The sol concentration was found to affect the swelling for two reasons, the salt fractionation effect and the trapped salt effect. Both of these cause the salt concentration in the supernatant fluid to be greater than that originally added to the crystals and so reduce the swelling.

A new method was used for extracting the solution from inside the gels by collapsing the gels by the addition of potassium hydrogen carbonate. The Volhardt titration was carried out on the extracted and supernatant solutions from about 250 gels. The ratio of the external to the internal chloride concentration was found to be approximately constant across the range of salt concentrations. Its average value was equal to 2.6, again in agreement with Coulombic attraction theory and showing the surface potential to be constant at about 70 mV.

The (r, c, T) boundary of the two phase colloid region was investigated by three methods. A plot of log c against Tc was linear within experimental accuracy, with a gradient of 0.077 K−1 or 13 K per log unit. This shows that the surface potential varies by only 1 mV per decade in the salt concentration. The system is therefore governed by the Dirichlet boundary condition and not by the Nernst equation.

Keywords

CATDLVO theoryNeutron diffractionOsmotic swellingPhase transitionsSalt fractionationTrapped saltVermiculite gels
Type
Research Article
Information
Clays and Clay Minerals , Volume 42 , Issue 5 , October 1994 , pp. 614 - 627
Copyright
Copyright © 1994, Clay Minerals Society

References

Braganza, L. F., Crawford, R. J., Smalley, M. V., and Thomas, R. K., (1990) Swelling of n-butylammonium vermiculite in water: Clays and Clay Minerals 38: 90–96.CrossRefGoogle Scholar
Crawford, R. J., Smalley, M. V., and Thomas, R. K., (1991) The effect of uniaxial stress on the swelling of n-butylammonium vermiculite: Advances in Colloid and Interface Science 34: 537–560.CrossRefGoogle Scholar
Derjaguin, B. V., and Landau, L., (1941) Theory of the stability of strongly charged lyophobic sols and of the adhesion of strongly charged particles in solutions of electrolytes: Acta Physicochimica 14: 633–662.Google Scholar
Ettelaie, R., (1993) On the Helmholtz free energy of the highly charged double plates in an electrolyte: Langmuir 9: 1888–1892.CrossRefGoogle Scholar
Garrett, W. G., and Walker, G. F., (1962) Swelling of some vermiculite-organic complexes in water: in Clays and Clay Minerals, Proc. 9th Natl. Conf., Lafayette, West, Indiana, 1960, Swinford, Ada, ed., Pergamon Press, New York, 557–567.CrossRefGoogle Scholar
Hashimoto, T., Todo, A., and Kawai, H., (1978) Analysis of interparticle interference effect based upon a paracrystal model: Polymer Journal 10: 521–537.CrossRefGoogle Scholar
Humes, R. P., (1985) Interparticle forces in clay minerals: Ph.D. thesis, Oxford University, Oxford, United Kingdom, 140–153.Google Scholar
ISIS User Guide (1992) B. C. Boland and S. Whapham, eds., SERC, Rutherford Appleton Laboratory, Report RAL 92–041.Google Scholar
Klaarenbeek, F. W., (1946) Over Donnan-even wíchten bíj solen van arabische gom: Ph.D. thesis, Utrecht.Google Scholar
Low, P. F., (1987) Structural component of the swelling pressure of clays: Langmuir 3: 18–25.CrossRefGoogle Scholar
Moody, K. R., (1992) Swelling of vermiculite-organic complexes in water: Part II thesis, Oxford University, Oxford, U.K., 26–29.Google Scholar
Norrish, K., and Rausell-Colom, J. A., (1963) Low angle X-ray diffraction studies of the swelling of montmorillonite and vermiculite: in Clays and Clay Minerals, Proc. 10th Natl. Conf., Austin, Texas, 1961, Swinford, Ada and Franks, P. C., eds., Pergamon Press, New York, 123–149.Google Scholar
Rausel-Colom, J. A., (1964) Small-angle X-ray diffraction study of the swelling of butylammonium vermiculite: Trans. Far. Soc. 60: 190–201.CrossRefGoogle Scholar
Rausell-Colom, J. A., Saez-Aunon, J., and Pons, C. H., (1989) Vermiculite gelation: Structural and textural evolution: Clay Miner. 24: 459–478.CrossRefGoogle Scholar
Smalley, M. V., (1990) Electrical interaction in macroionic solutions and gels: Molecular Physics 71: 1251–1267.CrossRefGoogle Scholar
Smalley, M. V., (1994) Electrostatic theory of clay swelling: Langmuir, to be published.CrossRefGoogle Scholar
Smalley, M. V., Thomas, R. K., Braganza, L. F., and Matsuo, T., (1989) Effect of hydrostatic pressure on the swelling of n-butylammonium vermiculite: Clays and Clay Minerals 37: 474–478.CrossRefGoogle Scholar
Sogami, I., (1983) Effective potential between charged spherical particles in dilute suspension: Phys. Lett. 96A, 199–203.CrossRefGoogle Scholar
Sogami, I., and Ise, N., (1984) On the electrostatic interaction in macroionic solutions: J. Chem. Phys. 81: 6320–6332.CrossRefGoogle Scholar
Sogami, I. S., Shinohara, T., and Smalley, M. V., (1991) Effective interaction of highly charged plates in an electrolyte: Molecular Physics 74: 599–612.CrossRefGoogle Scholar
Sogami, I. S., Shinohara, T., and Smalley, M. V., (1992) Adiabatic pair potential of highly charged plates in an electrolyte: Molecular Physics 76: 1–19.CrossRefGoogle Scholar
Townshend, D. J., (1992) Vermiculite gelation: Part II thesis, Oxford University, Oxford, U.K., 13–24.Google Scholar
Verwey, E. J. W., and Overbeek, J. Th. G., (1948) Theory of the stability of lyophobic colloids: Elsevier, Amsterdam.Google Scholar
Walker, G. F., (1960) Macroscopic swelling of vermiculite crystals in water: Nature 187: 312–313.CrossRefGoogle Scholar