Volume Changes of a Thixotropic, Sodium Bentonite Suspension during Sol-Gel-Sol Transition

Abstract
Dilatometric measurements during the sol-gel-sol transition of an air-free, thixotropic, sodium bentonite suspension revealed a reversible change in volume of about 2.4 X 10-4 percent. The volume of the suspension increased during gelation and decreased when the gel was subsequently liquified. This is taken as evidence of a progressive building up, during gelation, of a water structure less dense than normal.