Abstract
The structures of an amphiphilic graft conjugated copolymer, PVEO17,composing of a conjugated PPV backbone and PEO side chains, in bulk and solutions with THF and water have been investigated by small-angle x-ray scattering (SAXS), UV-Vis and photoluminescence spectroscopy. In bulk state, PPV main chains in PVEO17 stacked into flat disk microdomains dispersed in the EO side-chain matrix. Wide angle x-ray scattering revealed the existence of crystallization of PEO side chain. The structure of the polymer in solution was affected by the solvent quality and the polymer concentration. PVEO17 chains were well dispersed in THF. In aqueous solutions, PVEO17 chains aggregated significantly over the concentration range of 1wt% to 8wt%, where the polymer was found to self-organize into cylindrical micelles with the length and the aggregation number increased with increasing concentration. The photophysical properties of PVEO17 were affected by the degree of aggregation, where aggregation resulted in a red-shift of the PL. A gradual red shift of PL was also observed in going from the solution state to the precipitate to the bulk.