Mechanisms of the self-organization of star-shaped polymers with a varied structure of branching center based on fullerene C60 in solutions

The self-organization of star-shaped polymers in toluene has been studied by small-angle neutron scattering. Polystyrene stars with a mono-C-60 branching center are ordered into globular clusters (similar to 1700 nm in diameter), whereas stars with a double (C-60-C-60) center are ordered into anisotropic structures (superchains), which are linked (depending on the concentration) into triads (chain clusters similar to 2500 nm in diameter). On the contrary, heteroarm polystyrene and poly-2-vinylpyridine stars with a C-60 center are weakly associated into dimers. Moderately polar stars with arms composed of polystyrene and diblock copolymer (poly-2-vinylpyridine-poly-tret-butyl methacrylate) form short chains composed of four macromolecules, while stars of higher polarity based on polystyrene and poly-tret-butyl methacrylate form clusters containing similar to 12 macromolecules similar to 50 nm in diameter. Thus, by varying the structure of the center and the arm polarity, one can control the modes of star structuring.