Interfacial and surface adsorption phenomenon in the dissolution behavior of 8-hydroxy quinoline

Abstract

The solubilization and dissolution behavior of 8-hydroxyquinoline was studied in surfactant medium. Anionic surfactant - Sodium dodecyl sulphate (SDS), cationic surfactant - cetyltrimethylammonium bromide (CTAB), non-ionic surfactant - Triton X-100 were put to use while performing the work. Meaningful interaction of surfactant with cationic and anionic surfactants were only observed. In either of the surfactant medium, the solubility vs surfactant concentration profile has shown a maximum at around the concentration of the surfactant at which the micellization of the surfactant has begun i.e., cmc or critical micelle concentration was reached. In CTAB medium, the solubility of 8-hydroxyquinoline has shown double maxima, one of which was in the post-micellar region. The acid dissociation constant, binding constant of 8-hydroxyquinoline, Gibb’s free energy of solubilization and the partition coefficient (molar) between the aqueous and micellar aggregate phases were computed. Based on all the observations suitable explanations are extended. From the experimental results, the micelle-(8-HQ) binding constant, partition coefficient and free energy of solubilization was computed to supplement the assertions made.