A study of surfactant micelles with a fluorescent probe

Abstract

The fluorescence probe technique has been used to study micelles of anionic, cationic and non-ionic surfactants. The solute was pyrene. The formation of a fluorescent excited dimer (excimer) by pyrene means that this probe can be used not only to explore intramicellar kinetics, but also to monitor the manner in which micelles change their size. The change in size of ionic surfactants with electrolyte concentration and of non-ionic surfactants with temperature is explored. We have developed a simple method involving the effect of oxygen (in air) on the fluorescence spectrum for detecting statistical distribution effects in the solubilization of pyrene in micelles. The combination of fluorescence spectra with time-dependent fluorescence intensity (fluorescence 'decay') allows a full analysis.