The interaction between the aromatic organic counterion and ionic surfactant micelle

The UV absorbance of various aromatic organic counterions has been investig ated in the presence of ionic surfactant micelle. Addition of the cationic surfactant micelle to aqueous solutions of the aromatic organic salts induc es a red shift of the adsorption spectra. It is proposed that the red shift is caused by cation - pi interaction, which requires proper situation and distance between the surfactant's headgroup and the aromatic organic counte rion. By measuring the adsorption of the surfactant and the aromatic organi c counterions, it is discovered that different aromatic organic counterions adopt different configurations, This explanation is consistent with the NM R results.