Lipoidal eosin and fluorescein derivatives as probes of the electrostatic characteristics of self-assembled surfactant/water interfaces

Abstract

Lipoidal eosin and fluorescein derivatives have been investigated in order to determine whether or not they can be used to probe the electrostatic characteristics of surfactant monolayers spread at the air/water interface. The visible absorption spectra, fluorescence emission spectra, and acid-base behavior of 5-(N-hexadecanoyl)aminoeosin (HAE) and 5-(N-octadecanoyl)aminofluorescein (OAF) have been examined at aqueous/surfactant interfaces. For comparison the spectral properties and acid-base behavior of closely related water-soluble analogues of HAE and OAF in 1,4-dioxane/water mixtures have also been studied. Lipoidal fluorescein derivatives were assessed to be the most suitable lipoidal i..