The complexation of perfluorooctanoic acid (PFOA) and pyridine (as the model for the complexation of PFOA and polystyrene-b-poly(4-vinyl pyridine) (PS-b-P4VP)) in deuterated chloroform leads to an unusual low field shift of the C-13 NMR signal of the carbon atoms in the carboxyl groups of PFOA. Unlike the complexes of block copolymers with other small molecular surfactants in low-polarity organic solvents, the complexes of PFOA/PS-b-P4VP self-assemble in chloroform, forming vesicles when the molar ratio of PFOA to the pyridine units is greater than or equal to 1/5 and less than or equal to 1/1. When the molar ratio is 2/1, the PFOA molecules that are unconnected to P4VP chains are encapsulated in the aggregates rather than solubilized in the solvent, leading to a solid spherical morphology of the resultant aggregates. Moreover, the PFOA molecules both connected and unconnected to the P4VP chains are crystallized within the aggregates and melt at different temperatures.