Self-assembly of an amphiphilic diblock copolymer polysyrene-b-polyvinylbenzoic acid in ethanol

which is a selective solvent for the polybenzoic acid segment was studied by means of transmission electron microscopy．The diblock copolymers can self-assemble into nano scale aggregates with polystyrene segment as the core and polyvinylbenzoic acid segment as the corona．The morphology of the aggregates is mainly controlled by the ratio of the two segment of the diblock copolymer．As the content of the ethanol-insoluble polystyrene segment increased

the morphology can be changed from spheres to rods．The diameter of the aggregates increases slightly with concentration and decreases with the addition of CoCl2 salt．