Conjugated polyfluorene/polyaniline block copolymers—improved synthesis and nanostructure formation

Soluble poly(9,9-dialkylfluorene)/poly(2-alkylaniline) tri-block copolymers were synthesized following an improved two-step synthetic procedure: (i) aryl–aryl coupling of a 2,7-dibromo-9,9-dialkylfluorene according to Yamamoto in the presence of 4-bromoaniline as a monofunctional ‘end-capping’ reagent, and (ii) subsequent oxidative condensation with a 2-alkylaniline. The bluish colored conjugated—conjugated block copolymers were characterized by means of GPC, NMR, and UV-Vis spectroscopy. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) of spin-coated films clearly show the formation of nanostructured materials, indicating nanoscopic ordering on a length scale of approximately 100–300 nm.