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

Abstract

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 (d) ranging from 7.65 to 10.6 nm depending on the volume fraction of MH block (ϕMH), Flory–Huggins interaction parameter (χ), and degree of polymerization (N). The BCP architecture also governed the morphology of the BCPs, e.g. the AB-type diblock copolymer (ϕMH = 0.42), the ABA-type triblock copolymer (ϕMH = 0.40), and the A2B-type miktoarm star copolymer (ϕMH = 0.45) self-organized into cylinder (d = 7.65 nm), lamellar (d = 8.41 nm), and lamellar (d = 9.21 nm) structures, respectively.