Electronically active block polymers based on π-conjugated macromolecules have been investigated for applications where nanostructured electrodes are of prime import; however, controlling the nanoscale order of these materials has proven challenging. Here, we demonstrate that diblock copolymers that utilize a non-conjugated radical polymer moiety as the electronically active block assemble into ordered thin-film nanostructures. Specifically, the diblock copolymer polydimethylsiloxane-b-poly(2,2,6,6-tetramethylpiperidinyloxy methacrylate) (PDMS–PTMA) was synthesized via atom transfer radical polymerization to generate polymers with readily controlled molecular properties. Importantly, solvent annealing of the PDMS–PTMA thin films led to well-defined nanostructures with domain spacings of the order of ~30–40 nm.