Evidence of compartmentalization of naphthols in microemulsions from fluorescence quenching study

11-14The fluorescence characteristics of 1- and 2-naphthols (1-ROH and 2-ROH) and their corresponding naphtholates (l-RO - and 2-RO-) have been studied in NaLS-isobutanol-hexane-water microemulsions. On excitation, l-ROH dissociates completely and 2-ROH partially in water. In microemulsion system, however, on excitation 2-ROH does not undergo any dissociation whereas 1-ROH dissociates partially. The extent of dissociation of 1-ROH varies with changing microemulsion formulation. This phenomenon and the fluorescence quenching characteristics of naphthols and the corresponding naphtholates with carbon tetrachloride have been explained as due to compartmentalization of fluorophores and quencher in microemulsion media