A polystyrene-block-poly(4-vinyl pyridine) diblock copolymer (PS-b-P4VP) has been used to create nanosized toroid-like structures on nitrided silicon oxide and gold substrates via simple solvent annealing of spun cast films. The significance of the role of polymer-substrate interactions in de. ning the morphology of the self-assembled block copolymer structure is discussed. (C) 2009 Published by Elsevier B.V.