ION-EXCHANGE AND MOLECULAR ADSORPTION OF A CATIONIC SURFACTANT ON CLAY-MINERALS

The adsorption of hexadecylpyridinium chloride (HDPCl) from aqueous so lution on to the clay minerals kaolinite, attapulgite, vermiculite, al levardite and monocationic montmorillonites was investigated. The orga nic ion exchange capacity was determined from the section of the adsor ption isotherm characteristic of ion exchange adsorption. The values o btained were found to be related to the structures of the clay mineral s. Adsorption of Cl- ions was observed in the section relating to mole cular adsorption. The basal plane distances of swelling clay minerals were calculated from X-ray diffraction measurements. Formation of the adsorption layer could be explained by interlamellar expansion. Furthe r, the dispersion properties of the organocomplexes of tenside clay mi nerals in toluene were investigated. A correlation was established bet ween the swelling, disaggregation and structure-forming properties of the organocomplex dispersed in the organic liquid, and both tenside ad sorption and X-ray diffraction data.