The micellar structure of poly(styrenehyphen;butadiene) diblock copolymer/polystyrene homopolymer blends has been investigated by small angle xhyphen;ray scattering (SAXS) and transmission electron microscopy (TEM) as a function of copolymer concentration, copolymer block molecular weights, and homopolymer molecular weight. The SAXS from blends exhibiting spherical micelles, as evidenced by TEM, has been modeled using a polydisperse Percusndash;Yevick hard sphere fluid model to obtain the interparticle interference contribution to the scattered intensity. By combining this modeling with quantitative TEM and SAXS invariant analysis, the structure of the micelles as a function of the molecular parameters can be completely characterized. In addition, a transition from liquidhyphen;like to an ordered simple cubic arrangement of micelles has been observed upon increasing the copolymer concentration.
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