This proposal continues our investigations into polyelectrolyte-surfactant solutions which form thin films at the air-solution interface. Our previous work has investigated the interaction between the polyelectrolyte, polyethyleneimine and cationic alkyltrimethylammonium bromide (CnTAB) surfactant micelles in solution, showing that the micellar structures in solution reflect those found in the thin films at the solution surface, with a larger interaction apparent for micelles formed from CnTAB surfactants with longer tail lengths. In this proposal we will investigate the role of micelle curvature on the polymer-surfactant interaction in solution by using a surfactant with a larger headgroup (cetyltriethylammonium bromide) to increase the curvature and by using mixed micelles of C16TAB with a double chain quaternary ammonium surfactant DODMAB, to decrease curvature.