3.2.2.1. Effect of rod/coil ratio
Oligophenylenevinylenes (OPV)-coil diblock copolymers were shown to possess remarkable self-assembling abilities to form long cylindrical micelles in dilute THF/D2O solutions [82], [83] and [84]. The high molecular weight poly(ethylene glycol) (PEG) block drove the self-assembled cylindrical micelles of a core diameter about 8–10 nm, which was composed of an OPV block and surrounded by a PEG corona (Fig. 9) [82]. A further investigation on the OPV-b-poly(propylene glycol) (PPG) block copolymers with different concentrations of coil-selective solvent D2O were reported ( Fig. 10) [83]. As shown in the figure, bundles of fibers with a strong yellowish-green fluorescence are clearly observed at their critical water content. The packing structures for the block copolymers are consisted of a hydrophobic OPV inner core and a hydrophilic PEG or PPG outer shell.