Self-Assembly Behavior of Amphiphilic C60-End-Capped Poly(vinyl ether)s in Water and Dissociation of the Aggregates by the Complexing of the C60 Moieties with Externally Added γ-Cyclodextrins

C-60-end-capped polymers consisting of an amphiphilic poly(2-methoxyethyl vinyl ether) (PMOVE) main chain were synthesized by living cationic polymerization using a C-60-functionalized initiator (C60VE-TFA) in the presence of EtAlCl2 as an activator and dioxane as an added base. The obtained polymers (C-60-PMOVE) dissolved in a wide range of solvents including water and exhibited solvatochromism depending on the polarity of the media employed. This phenomenon was attributed to self-assembly in polar media due to hydrophobicity of the C-60 moieties at the terminus of the amphiphilic polymer chain. Furthermore, the addition of gamma-cyclodextrin (gamma-CD), a strong host molecule for fullerenes, to the self-assembled system brought about the dissociation of the aggregates into molecularly dispersed free polymer chains. Titration of the aqueous solution of the self-assembly of C-60-PMOVE with gamma-CD indicated the possible formation of inclusion complexes of C-60-PMOVE and gamma-CD, and this binding process occurs in a positive cooperative manner.