AGGREGATION CHARACTERISTICS OF LASER DYE RHODAMINE 6G IN AQUEOUS SURFACTANT SOLUTIONS

Abstract

Abstract— –The role of surfactants as deaggregating agents for the laser dyes is investigated by spectrophotometry using Rhodamine 6G as a representative. A method to estimate the fraction of dye present as monomer, dimer and as a monomer‐surfactant (monomer or micelle) complex is described. It is shown that among the surfactants, cetyl trimethyl ammonium bromide, Triton X‐100, sodium lauryl sulfate (SLS) and potassium oleate, the anionic ones are the most effective in suppressing the aggregation of Rhodamine 6G. While the non‐ionic surfactant is found to be effective only above its critical micellar concentration, the cationic surfactant has no effect on aggregation. The optimum concentration of SLS needed for suppression of dye‐dimers is estimated.