ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 39, Number 3
JKCSEZ 39(3)
June 20, 1995 

At low concentration a simplified model of organic dye-surfactant system has been used to evaluate. By applying the resultant three parameter equation to the experimental data, values for the equilibrium constants for the ion-pair formation (K_O), surfactant molecule addition to aggregates (K_S) and dye aggregation reactions (K_D) could be calculated and changes of free energy have obtained from its values. K_O and K_S values were larger than those expected electrostatic interaction indicatihng a hydrophobic contribution and the K_D values were about 10~20 times higher than those found for association in pure aqueous solutions which can be ascribed to the screening effect of the electrostatic repulsion.