Solubility and Micellization Behavior of C₆₀ Fullerenes with Two Well-Defined Polymer Arms

Abstract

1,4-Disubstituted, low-polydispersity C60 derivatives of the types C60−(PS)2, C60−(PVP)2, and C60−(PS−PVP)2, where PS is polystyrene, PVP is poly(p-vinylphenol), and PS−PVP is a diblock copolymer of this sequence, were prepared by applying the nitroxide-controlled free radical polymerization technique and studied with their solubility behaviors in some organic solvents. The first clear experimental evidence was obtained for the formation of multimolecular micelles of C60-bearing polymers under certain conditions: for example, light-scattering measurements showed that the C60−(PVP)2, C60−(PS−PVP)2, and C60−(PS)2 samples with a number-average molecular weight of a polymer arm roughly about 10 000 formed stable micelles in dilute tetrahydrofuran (THF) solution with association numbers of about 20, 6, and 1 (no micellization), respectively. The solvent power of THF for the mother polymers increases in this order. The saturation solubilities S C 60 of the C60 moiety in C60−(PS)2 and C60−(PVP)2 were determined as a function of the PS and PVP chain lengths, showing that, in THF, the S C 60 in the PS adduct is exceptionally large, much larger than that in the PVP adduct of the same chain length, in accord with the mentioned micellization tendency in dilute solution. On the other hand, C60−(PVP)2 showed a reasonable solubility in a polar solvent (methanol), in which C60−(PS)2 was little soluble. The micellization was found to be accompanied by characteristic changes in the UV−vis spectra, depending on micelle size.

Preparation and Toroid Formation of Multiblock Polystyrene/C60 Nanohybrids

“…A similar result was previously reported by Okamura et al 16 and Ravi et al 18 The organic structures of the PS/C 60 nanohybrids have been characterized with FTIR. The presence of C 60 moieties of the PS/C 60 nanohybrids is characterized with UVÀvis spectroscopy.…”

Novel C60‐Anchored Two‐Armed Poly(tert‐butyl acrylate): Synthesis and Characterization

“…Treatment of C 60 with polymer 4, iodine, and 1,8-diazabicyclo [5,4,0]undec-7-ene (DBU) in toluene at room temperature yielded C 60 -anchored two-armed PtBA 5. Figure 1 displays the GPC traces of polymers 4 and 5 by UV and RI dual detectors.…”

“…Mathis et al [3] synthesized polystyrene and polyisoprene-grafted star-shaped macromolecules with a C 60 core by adding 'living' anionic polymers onto C 60 . Moreover, Fukuda et al [4] described the preparation of C 60 -bound polystyrene with a narrow molecular distribution by the reaction of C 60 with 2,2,6,6-tetramethylpiperidine-Noxyl (TEMPO)-end-capped polystyrene. Our group [5] also prepared star-shaped C 60 -based polyurethanes with six well-defined polymeric arms via condensation between polyhydroxylated C 60 and isocyanated polyether prepolymers.…”

Organometallic Ferrocene- and Phosphorus-Containing Polymers: Synthesis and Characterization

“…The possibility to develop materials possessing the unique properties of C 60 motivated these studies. In particular C 60 has been incorporated into different kinds of organic or inorganic materials, such as polymers [138][139][140][141][142][143][144][145][146][147] dendrimers [148][149][150][151][152][153][154][155][156][157][158] sol-gel matrices [159][160][161][162] and nanospheres [163][164][165][166][167]. C 60 has been synthesized by many researchers and various characteristics have been studies.…”