Hierarchical nanostructures of organosilicate nanosheets within self-organized block copolymer films

Living anoinic polymerization of methacrylate-functionalized polyhedral oligomeric silsesquioxane (POSS), resulting in high degree polymerization (DP) of the POSS chain and narrow polydispersity index (PDI) leading to the ordering of the POSS units within the microphase-separated domains, was reported. The (WAXS) patterns of unannealed and annealed PS-b-PMAPOSS show a peak scattering ratio of 1, 2, and 3, which is consistent with lamellae morphology. The annealing of POSS is followed by reflection at 5 nm, which corresponds to twice the calculated length between the methacrylate (MA) backbone and POSS cage. The regular array of POSS sheets in the film with a d spacing of 5 nm is due to interchain aggregation of POSS units and the POSS aggregation is likely to stretch the MAPOSS chain. The results also show that the POSS sheet length is same as PMAPOSS chain length.