The interaction of the zwitterionic phospholipid dipalmitoylphosphatidylcholine (DPPC) with four fluorene- and thiophene-based conjugated polyelectrolytes (CPEs) will be investigated using small angle neutron scattering (SANS). At appropriate concentrations, DPPC is known to self-assemble into mutlilamellar liposomes, which can be isolated into unilamellar vesicles via extrusion. Photoluminescence and dynamic light scattering studies have indicated that these CPEs can co-assemble with DPPC within the bilayer or alternatively be introduced into pre-formed DPPC vesicles via permeation. The proposed CPEs vary in terms of the valency, density and distribution of charged groups pendant to the conjugated backbone. SANS will be used to probe the structure of the co-assembled aggregates formed and to provide further insight into electrostatic and hydrophobic interactions in these systems.