Search for the form of fullerene C60 in aqueous medium

Abstract

A transfer of fullerene C(60) to water was achieved by sonication of a two-phase system of water and C(60) in organic solvents, namely, benzene and toluene. Resulting aqueous dispersions were analyzed electrochemically, spectroscopically, by MALDI-MS and AFM methods. Samples prepared from benzene yield the formal redox potential very close to a value expected from the correlation of redox potentials and solvent donor numbers. However, these samples are not stable and C(60) precipitates out of the aqueous dispersion. Sonication of the toluene/water system produces stable system, in which the measured formal redox potential of C(60) is less negative. Stabilization of C(60) clusters in water is achieved by the presence of an organic amphiphile and spectroscopic methods indicate the presence of benzoate formed during sonication of a toluene/water mixture.

Surface Modifications of Nanodiamonds and Current Issues for Their Biomedical Applications

“…These colloidal properties constitute an important asset for nanodiamonds compared to other carbon nanomaterials. Fullerenes or carbon nanotubes exhibit hydrophobic behavior and their stability in water suspension can only be obtained after their functionalization [178][179][180]. These colloids of NDs in water were also used to obtain homogeneous seeding of substrates for CVD growth of thin diamond films [181,182].…”

Water around fullerene shape amphiphiles: A molecular dynamics simulation study of hydrophobic hydration

“…45,92,132 To this end, the change in free energy for transferring an isolated C 60 solute from water to octane is defined as ∆∆G t = −64.89 kJ/mol. Octane is used to imitate the interior of biomembrane; 129 therefore, results for water-alkane free energy of transfer are expected to be in the same range for the transfer from water to the hydrophobic core of lipid membrane, though the latter differs from the isotropic octane phase in chain ordering and packing, density and two-dimensional solute confinement.…”

“…36,[38][39][40][41] A comprehensive research on the factors of fullerene solvation or self-organization in solution requires a complete set of physico-chemical properties, including solubility, solvation free energy, and entropy changes for a more realistic description of the solvated system. Although most of these data can be obtained experimentally, 26,[42][43][44][45] this approach is still hampered by extremely low solubility of fullerenes in water (7.96 ng/l) and a high level of aggregation. Therefore, most previous experiments concerning factors of solvation focused on colloid rather than molecular C 60 -form (a true solution).…”

Beyond nC60: strategies for identification of transformation products of fullerene oxidation in aquatic and biological samples

“…Several factors are known to affect the colloidal stability and aggregation behavior of C 60 , including pH and the presence of electrolytes, surfactants, organic matter, and electrochemical irradiation [51–57]. The chemistry and forces behind n C 60 particle formation have been scrutinized in detail [58–60]. Recently, a fraction of the fullerenes in these colloidal n C 60 particles was shown to be enriched in hydroxyl moieties that stabilize the n C 60 aggregates [59].…”