This proposal continues our investigations into polyelectrolyte-surfactant films at the air-solution interface. Using mixtures of cationic and anionic surfactants (CTAB/SDS) we have found that thick films form with a wider range of polymers than when using cationic surfactants alone, having structures controlled by CTAB:SDS molar ratio. Here we wish to extend this work by investigating incorporation of sparingly soluble species in mixed micelles to work towards application of these films in controlled release systems. Previously we studied cyclohexane and cyclohexanol in cationic surfactant-PEI films, so we propose to study these additives also in cat-anionic surfactant-PEI films to compare with our earlier work. We will also study incorporation of Nile red, a dye used in fluorescence studies of encapsulation/release to understand the effect of this dye on mesostructures in these films