Interaction of 1-anthracene sulphonate with cationic micelles of alkyl trimethyl ammonium bromides (CnTAB): A spectroscopic study

The emission properties of 1-anthracene sulphonate (1-AS) have been studied in cationic micellar media of alkyl trimethyl ammonium bromides (CnTAB) of varying chain lengths. The changes in the emission characteristics as a function of surfactant concentration have been utilized to determine the binding constant of the probe with the micelles and location of the probe within these micelles. The interactions of 1-AS with the cationic micelles depend on the hydrophobic chain length of the cationic surfactants. The binding constants of 1-AS with CnTAB micelles decrease with decreasing n. The fluorescence of 1-AS is quenched by cetyl pyridinium chloride (CpCl) at the surface of the cationic micelles. The rate of fluorescence quenching decreases with decrease in alkyl chain length of the cationic surfactants.