1IntroductionIn this paper, a novel water-soluble block copolymer with rod-coil structures was prepared using polyfluorene (PF) as rod segment and polyethylene glycol (PEG) as coil segment in the main chain. A new but simple way of polycondensation ( shown in Scheme 1 ) was employed, compared with tedious atom transfer radical polymerization and ionic polymerization approaches.