Title: Bentonite
CAS Registry Number: 1302-78-9
Additional Names: Wilkinite
Literature References: A colloidal native hydrated aluminum silicate (clay) found in the midwest of the U.S.A. and in Canada. Consists principally of montmorillonite, Al2O3.4SiO2.H2O. Usually contains some magnesium, iron, and calcium carbonate. Review: J. Alexander, Ind. Eng. Chem. 16, 1140 (1924).
Properties: The color in the massive condition varies from yellowish-white to almost black. The powder is cream colored to pale brown. It has the property of forming highly viscous suspensions or gels with not less than ten times its weight of water. The property of forming gels is very much increased by the addition of small amounts of alkaline substances such as magnesium oxide.
Use: As of Fuller's earth; as emulsifier for oils; as a base for plasters. Pharmaceutic aid (suspending agent). |