Binding of sodium dodecyl sulfate (SDS) to the ABA block copolymer pluronic F127 (EO97PO69EO97):: F127 aggregation induced by SDS

It has been established that sodium dodecyl sulfate (SDS) binds to the micelles and monomers of the block copolymer F127. SDS binds to the monomeric unassociated F127 in the form of polymer/bound SDS micellar complexes. SDS binds to F127 micelles first forming mixed micelles, which dissociate into smaller mixed aggregates and then to single F127 unassociated monomers. A third interaction of SDS, which involves promotion of F127 micelles at concentrations up to 3 degreesC below the critical micellar temperature of pure F127, was identified ana is investigated in the present work. The formation of such SDS-induced mixed micelles was monitored using differential scanning calorimetry, light scattering, isothermal titration calorimetry, and a SDS selective electrode for electromotive force measurements. These investigations have shown how the different binding and aggregation processes between SDS and F127 involving induced micellization, growth of mixed micelles, breakdown of mixed micelles, and binding of SD'S to monomeric F127 can be identified and characterized.