Effects of surfactants on the molecular aggregation of rhodamine dyes in aqueous solutions

The aggregative properties of rhodamine 6G (R6G) and rhodamine B (RB) in aqueous solutions of cationic and anionic surfactants were studied using the absorption and fluorescence spectroscopic methods. The dye–surfactant interactions in aqueous and surfactant solutions were also studied. The spectroscopic studies were extended in order to determine the effect of molecular structure of the surfactants on the aggregative behavior of the rhodamine dyes. The aggregate structures and the nature of the interacting pairs in these dyes were discussed using the exciton theory.