Blends of functionalized polystyrenes (3NPS) having three dimethylamino groups {N(CH3)(2)} at one end, with sulfonic acid end-capped polyisoprenes (HO3SPI) were prepared in a ratio of N(CH3)(2)/ SO3H = 1. The morphology of these blends was studied by small-angle X-ray scattering and transmission electron microscopy and the associated dynamics by rheology. The results of the microdomain investigation, as well as of the associated dynamics, provide unambiguous evidence for controlled miktoarm star block copolymer formation via ionic interactions.