화학공학소재연구정보센터
Macromolecules, Vol.48, No.16, 5496-5503, 2015
Hydrogen-Bonding-Induced Nanophase Separation in Giant Surfactants Consisting of Hydrophilic [60]Fullerene Tethered to Block Copolymers at Different Locations
Phase behaviors of two series of giant surfactants consisting of a hydrophilic [60]fullerene (AC(60)) molecular nanoparticle (MNP) tethered to a polystyrene-block-poly(ethylene oxide) (PS-b-PEO) block copolymer were investigated. The physical location of AC(60) MNP was specifically designed to be at the end of the PS block (AC(60)-PS-PEO) or at the junction point [PS-(AC(60))-PEO] between the PS and PEO blocks. Sell-assemblies of these two series of giant surfactants in the bulk revealed that the incorporation of AC(60) MNPs leads to nanophase separation of originally disordered PS-b-PEO block copolymers having their block lengths shorter than the limiting value for the nanophase separation in the PS-b-PEO precursors. Based on small-angle X-ray scattering and transmission electron microscopy results, three ordered nanostructures were observed in these two series of giant surfactants, including lamellae, double gyroids, and cylinders, all of which possess domain sizes smaller than 10 nm. Two pairs of topological isomers, AC(60)-PS50-PEO45 and PS50-(AC(60))-PEO45 as well as AC(60)-PS78-PEO45 and PS78-(AC(60))-PEO45, were explicitly investigated to reveal the topological effect on self-assembly behaviors of these giant surfactants. The results provided evidence of the physical location and distribution of the AC(60) MNPs within the nanophase-separated domains and demonstrated abilities to stabilize the different structures via topological variations. This study thus affords an efficient and practical strategy for the design and preparation of giant surfactants to construct ordered nanostructures for technologically relevant applications.