Abstract:

The potential large-scale production of fullerene C₆₀ and its widespread use in consumer products may translate into occupational and public exposure and in long-term environmental exposure. To assess the risk and fate of C₆₀ in the environment, it is important to understand its solvate formation in common industrial solvents as the solvates may affect various properties of C₆₀ including reactivity and toxicity, particularly when solvates occur in C₆₀ clusters. In this study, the solubility measurements in mixed solvent system can provide useful information about solvate formation. The solubility of C₆₀ was measured in pure toluene, tetrahydrofuran, ethanol, and acetonitrile to be 3000, 11, 1.4, and 0.04 mg/L, respectively. Additionally, the solubility of C₆₀ was measured in mixtures of toluene−acetonitrile, toluene−ethanol, toluene−tetrahydrofuran, and acetonitrile−tetrahydrofuran. The solubility data were modeled with some accuracy using Wohl’s equation. The estimated crystal energy term for C₆₀ in tetrahydrofuran was different than that in the other solvents, indicating that the C₆₀ solid phase in equilibrium with tetrahydrofuran solution may be a solvated crystal.