THE ASSOCIATION PARAMETERS OF BROMIDE AND IODIDE-IONS WITH CATIONIC MICELLES USING STEADY-STATE FLUORESCENCE QUENCHING MEASUREMENTS

The fluorescence quenching of 2-aminonaphthalene (2-AN) and 2-aminochr ysene (2-AC) by Br- and I- ions was studied in different concentration s of cetyltrimethylammonium bromide (CTAB) and cetyltrimethyl ammonium chloride (CTAC) detergents. The results show that both inorganic ions are partitioned and bound to both micelles, with the exception of 2-A C where I- ions distribute between the aqueous and micellar phases. Th e partition coefficients and binding constants of I- ions in these mic eIles are much larger than those of Br- ions. The decrease in the quen ching rate constant (k(q)) in the micelies is larger for 2-AC than for 2-AN, indicating that 2-AC is present in the micelles at a site at wh ich the viscosity is high.