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A combination of transmission electron microscopy (TEM), dynamic light scattering (DLS), static light scattering (SLS), and flow field-flow fractionation (flow-FFF) techniques were used to study the solution behavior of diblock copolymers of polystyrene-block-polybutadiene in hexane. Results obtained from all these techniques showed that the diblock copolymer forms micelles in selective solvents. Analysis via DLS indicates that, in hexane, the micelles have a hydrodynamic diameter (D h) of ∼140 nm. It was also found that each micelle is composed of a few hundred polymer molecules. Flow FFF was used to analyze the diblock copolymer in hexane and in a solution of hexane and ethylbenzene. The data obtained via flow FFF show the presence of both single polymer molecules and micelles. It was also observed that, upon titration of a diblock copolymer solution in hexane by ethylbenzene, the micelles started to dissolve, and at 23% ethylbenzene the micelles completely dissolved. Moreover, the diblock copolymer solution in hexane was titrated with styrene, and the effect of the micellar structure was studied by both dynamic light scattering (DLS) and static light scattering (SLS).

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