Relation between Swelling, Surface Area and b Dimension of Na-Montmorillonites*

John W. Odom and Philip F. Low
Department of Agronomy, Purdue University, W. Lafayette, Indiana 47907
* Journal Paper No. 6877, Purdue University Agricultural Experiment Station.

Abstract: From swelling and surface area measurements, it was found that the swelling of a montmorillonite depends linearly on the fraction of its layers that fully expand in water and that this fraction, in turn, depends linearly on the b dimension of the unit cell. Therefore, swelling is a linear function of the b dimension. However, the specific surface area of a montmorillonite is a linear function of its b dimension only if no partially expanded layers exist. It was also found that the distance between fully expanded layers at a given applied pressure is the same for all montmorillonites.

Key Words: Expansion • Interlayer • Montmorillonite • Surface • Swelling

Clays and Clay Minerals; October 1978 v. 26; no. 5; p. 345-351; DOI: 10.1346/CCMN.1978.0260505
© 1978, The Clay Minerals Society
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