The steady state fluorescence measurements have been performed oil Pluronic F127 and P103 with dimethylene-bis-(dodecyldimethylammonium) (12-2-12) mixtures at 21-40 degrees C. From the pyrene fluorescence, the critical micelle concentration (cmc), micelle mole fraction (x), micropolarity, and aggregation number have been computed for both mixtures over the whole mixing range at different temperatures. These micelle parameters indicate that the mixed micelle formation between the Unlike components of both mixtures takes place due to the synergistic interactions and which increase with an increase in temperature. (c) 2005 Elsevier Inc. All rights reserved,