STUDY OF BETA-CYCLODEXTRIN DODECYLTRIMETHYLAMMONIUM BROMIDE COMPLEX INTO WATER-ISOPROPANOL MIXTURES/

Stability constants of the beta-cyclodextrin-dodecyltrimethylammonium complex in water-isopropanol mixtures for compositions between 0 to 34 .5 wt% isopropanol were determined by potentiometric measurements. A s ignificant increase in the dissociation constant of the complex was ob served when isopropanol was added to its solution in water. Standard G ibbs energies of transfer of the surfactant (DTABr) from water to aque ous mixtures were determined by potentiometric measurements with a jun ctionless cell. The destabilization of this complex in the presence of alcohol is largely explained by a significant stabilization of the ca tionic amphiphile.