Self-assembly of maltoheptaose-b-PMMA block copolymer systems: 10nm Resolution in thin film and bulk states

Carbohydr Polym. 2017 Aug 15:170:15-22. doi: 10.1016/j.carbpol.2017.04.029. Epub 2017 Apr 19.

Abstract

This paper describes the self-assembly of oligosaccharide-based hybrid block copolymers (BCPs) consisting of maltoheptaose (MH) and poly(methyl methacrylate) (PMMA) into 10nm scale lamellar and cylindrical phases depending on the volume fractions of MH (ϕMH) and the annealing process. Time resolved SAXS study of the BCP bulk samples during thermal annealing indicated that the BCPs phase separate into 10nm scale periodical structures. The solvent vapor annealing induced self-organizations of the BCP into different phases depending on ϕMH and the weight fraction of THF/H2O. BCPs with relatively higher ØMH, MH-b-PMMA3kMH=0.27) and MH-b-PMMA5kMH=0.16) self-organized into lamellar phases while the BCP sample with relatively lower ϕMH, MH-b-PMMA9kMH=0.10), self-organized into cylindrical phase by using THF/H2O=1/4 (w/w). On the other hand, the solvent vapor annealing with larger fraction of THF, i.e. THF/H2O=2/3 (w/w), induced cylindrical phases for MH-b-PMMA3k and MH-b-PMMA5k.

Keywords: Poly-/oligosaccharide-based block copolymers; Rod-coil block copolymers; Self-assembly; Solvent vapor annealing.