Sub-10 nm Scale Nanostructures in Self-Organized Linear Di- and Triblock Copolymers and Miktoarm Star Copolymers Consisting of Maltoheptaose and Polystyrene

The present paper describes the sub-10 nm scale self-assembly of AB-type diblock, ABA-type triblock, and A₂B-type miktoarm star copolymers consisting of maltoheptaose (MH: A block) and polystyrene (PS: B block). These block copolymers (BCPs) were synthesized through coupling of end-functionalized MH and PS moieties. Small-angle X-ray scattering and atomic force microscope investigations indicated self-organized cylindrical and lamellar structures in the BCP bulks and thin films with domain spacing (<i>d</i>) ranging from 7.65 to 10.6 nm depending on the volume fraction of MH block (ϕ_MH), Flory–Huggins interaction parameter (χ), and degree of polymerization (<i>N</i>). The BCP architecture also governed the morphology of the BCPs, e.g. the AB-type diblock copolymer (ϕ_MH = 0.42), the ABA-type triblock copolymer (ϕ_MH = 0.40), and the A₂B-type miktoarm star copolymer (ϕ_MH = 0.45) self-organized into cylinder (<i>d</i> = 7.65 nm), lamellar (<i>d</i> = 8.41 nm), and lamellar (<i>d</i> = 9.21 nm) structures, respectively