Aggregation and microenvironmental properties of gemini and conventional mixed surfactants systems: A fluorometric study

Aggregation behavior of cationic gemini (hexanediyl-1,5-bis(dimethylcettylammonium bromide) (16-5-16)) surfactant with conventional single chain surfactants cetyltrimethylammonium bromide (CTAB) and tetradecyltrimethylammonium bromide (TTAB) were studied with the help of fluorescence measurements. Fluorescence probe is a proficient technique for examining the surfactant-surfactant interaction and aggregation. The micelle aggregation number (N (agg)) was measured using steady-state fluorescence quenching method. The micelle aggregation numbers of binary combinations fall between those of constituent surfactants. The micropolarity (I (1)/I (3)), binding constant (K (sv)) and dielectric constant (D (exp)) of mixed systems were determined from the ratio of peaks intensity in the pyrene fluorescence spectrum. The I (1)/I (3) values were found to be more than > 1, showing more polar environment around pyrene in the mixed micelle as compared to the pure micelles.