1-Methyl-8-oxyquinolinium betaine moiety as a probe of surfactant self-assembly systems

Abstract

The factors that influence the solvatochromism and acid-base behaviour of 5-octadecyl-1-methyl-8-oxyquinolinium betaine (FOEHQ) and 7-octadecyl-1-methyl-8-oxyquinolinium betaine (SOEHQ) in aqueous micellar systems have been identified. This has been achieved by comparing the spectral and acid-base properties of FOEHQ and SOEHQ in the surfactant self-assembly systems with those of FOEHQ and SOEHQ in 1,4-dioxane/water mixtures and those of 1 -methyl-8-oxyquinolinium betaine (MEHQ) in both 1,4-dioxane/water mixtures and aqueous electrolyte solution. It is concluded that the solvatochromism of the MEHQ moiety can be employed to obtain information about the interfacial solvent properties of surfa..