초록 |
Recently block copolymers embedded with nanoparticles have been studied in various scientific fields including electronics, biotechnology, and catalysis due to the special size effect. Block copolymers belong to a broad class of compounds that can self-assemble into ordered phase with periodic nano-structure. The addition of nanoparticles to block copolymers can significantly change the range of accessible self-assembled morphologies and nanoparticles are selectively coordinated by one block due to difference of their entropic & enthalpic interaction. In case of thin films, surface property difference among nanoparticles and each domain of block copolymers becomes important factor of its surface orientation. In this study, we investigated surface orientation of nanoparticles in block copolymer thin films. PS-b-PMMA block copolymer and γ-Fe2O3 & Ag nanoparticles capped with oleic acid were synthesized and used. We observed that nanoparticles were selectively located one microdomain on bulk PS-b-PMMA after thermal annealing, as confirmed by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) experiments. We also studied where nanoparticles existed in the film after thermal annealing and in which domain nanoparticles existed on the perpendicular microdomain film surface using TEM and atomic force microscopy (AFM). |