CHANGE IN THE MICELLAR AGGREGATION NUMBER OR IN THE SIZE DISTRIBUTION- A DYNAMIC FLUORESCENCE QUENCHING STUDY OF AQUEOUS CETYLTRIMETHYLAMMONIUM CHLORIDE

Aqueous solutions of cetyltrimethylammonium chloride were studied by m eans of dynamic fluorescence quenching measurements to get information on the micellar aggregation number and size polydispersity as a funct ion of surfactant concentration. The global analysis of multiple decay curves provided estimates with improved accuracy and precision and in dicated a reduced polydispersity upon increasing surfactant concentrat ion. As the quenching rate slows with increasing surfactant concentrat ion it is concluded that there is a micellar growth, but that this gro wth preferably increases the aggregation number for the smaller aggreg ates in the initially polydisperse solutions.