Change in the micellar aggregation number or in the size distribution?: a dynamic fluorescence quenching study of aqueous cetyltrimethylammonium chloride

Abstract

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