We intend to study the phase behaviour of 2 cationic polythiophenes, P3MAHT and P3ImiHT, in the presence of the perfluorinated surfactant potassium heptadecafluoro-1-octanesulfonate in D2O. Previous studies by SANS have shown that these polymers form structured complexes with the anionic surfactant sodium dodecyl sulfate. Given the enhanced rigidity of the perfluorinated surfactant to be used here, we expect the polymer-surfactant complexes formed will additionally exhibit long-range translational order. Our main objective for this experiment is to determine the solution structure of both polymers as a function of surfactant mole fraction using SANS, and to determine the corresponding phase diagrams. Changes in the organisation of the polymer-surfactant complexes should yield a dramatic influence on the photophysical properties, which will also be investigated using optical spectroscopy.