Solvation of C-60 Fullerene and C60F48 Fluorinated Fullerene in Molecular and Ionic Liquids

摘要

The association and dispersion of C-60 fullerene and C60F48 fluorinated fullerene in molecular and ionic solvents are studied using molecular dynamics simulations and dissolution experiments, with the aim of improving our understanding of nanocarbon materials interacting with liquid media. Fullerenes have uniform sizes and are devoid of edges and were chosen as models of wider classes of carbon nanomaterials. We parametrized a new atomistic force field for fluorinated nanocarbon materials and then used molecular dynamics to calculate structural quantities and potential of mean force. The aggregation in different solvents was assessed by UV/vis spectroscopy. The solvents considered include water, organic molecules, and ionic liquids, and we studied the effects of functional groups on the cation and of changing anions. Ionic liquids with a long alkyl chain on the cation are better solvents for C60F48 than for C-60, revealing the stronger hydrophobic nature of C60F48. Surprisingly, an ionic liquid with a benzyl group has no particular affinity for C-60. We observed nonadditive solvent effects related to the chemical structure of the ionic liquids, with the combination of a favorable anion (thiocyanate) with a long cation side chain (also favorable) not leading to enhanced affinity toward C60F48.