INFLUENCE OF ELECTROLYTES ON ADSORPTION OF CETYLTRIMETHYLAMMONIUM BROMIDE ON LIMESTONE FROM AQUEOUS-SOLUTIONS

Specific features of adsorption of cetyltrimethylammonium bromide (CTA B) on limestone from aqueous solutions in the presence of different ba ck;ground electrolytes such as KBr (10(-3) M), KNO3 (10(-2) M), MgCl2 (10(-3) M), and Na2CO3 (10(-2) M) were investigated. The shape of adso rption isotherm and the value of adsorption were shown to depend on th e nature of electrolyte. In solutions of indifferent electrolytes with a CTAB concentration equal to 10% of the critical micellization conce ntration, associates are formed at the solid surface, and the equilibr ium concentration of CTAB does not reach CMC. On the contrary, in solu tions of nonindifferent electrolytes association of CTAB occurs in bul k solution, and a sharp increase in adsorption is observed when the eq uilibrium concentration of CTAB is equal to CMC.