SURFACTANT AGGREGATION NUMBER AND POLYDISPERSITY OF SDS+1-PENTANOL MIXED MICELLES IN BRINE DETERMINED BY TIME-RESOLVED FLUORESCENCE QUENCHING

Size and polydispersity of sodium dodecyl sulfate (SDS) + 1-pentanol direct mixed micelles have been investigated by means of the time-resolved fluorescence quenching method in the system SDS/1-pentanol/water/NaCl ([SDS] = 0.0331 M, [1-pentanol] = O 42 M, and [NaCl] = 6.5 g/L of water). This method reveals high polydispersity in micellar size. Several size distribution models have been tested. The one that best fits the data is a double Gaussian distribution which suggests that two populations of mixed micelles might be present in the solution, centered on the SDS mean aggregation numbers of 75 and 830. © 1990 American Chemical Society.