The Spatial Distribution of Nanoparticles and Nanorods in Block Copolymer-Based Supramolecules of PS-b-P4VP

It is confirmed that the incorporation of nanoparticles and nanorods into block copolymer-based supramolecules of poly(styrene-b-4-vinylpyridine) (PS-b-P4VP) possess well selective spatial distribution into P4VP(PDP) microdomain. In this study, we investigate the effect of molecular weight of block copolymer on the spatial distribution of nanoparticles controlled by small molecules. With small molecular weight block copolymer, the spatial distribution of nanoparticles varies with different amount of PDP. However, with large molecular weight block copolymer, nanoparticles disperse around the center of P4VP(PDP) domain regardless of the amount of PDP. Favorable incorporation of nanoparticles into bended lamella is observed. Moreover, Nanorods tend to orientate perpendicular to the lamella of PS-b-P4VP when forming special aggregations of nanorods in the presence of excess free PDP in P4VP(PDP) microdomain.
Small molecules not only tailor the incorporation of various nanoparticles into supramolecular assembly by favorable mixing properties, but direct the supramolecular assembly to various morphologies. Besides, small molecules with excess amount can swell the P4VP(PDP) domain in similar to the effect of selective solvent toward P4VP.