Fluorescence Behaviors of Fluorescent Probes in Aqueous Solutions of Anionic Surfactants

Abstract

Fluorescence spectra of 4-methyl-7-anilinocoumarin (MAC) and 4-methyl-7-diethylaminocoumarin (MDC) were measured in aqueous solutions of anionic surfactants. CMC was determined from solubilization curves of fluorescent probes in surfactant micelles. This CMC was lower than the value determined from specific electric conductivity. The polarity of the region where the solubilization of fluorescent probes took place was estimated by the measurements of quantum yield and maximum wave number of the probe in aqueous solutions of surfactants.
MAC formed a complex with sodium dodecylbenzenesulfonate (SDBS) by a strong hydrophobic interaction below CMC. However, MDC did not form a complex with SDBS.