Physico-chemical properties of C60(OH)22–24 water solutions: Density, viscosity, refraction index, isobaric heat capacity and antioxidant activity

This paper investigates the physico-chemical properties of several polyhydroxylated fullerene (fullerenol, C60(OH)22–24) water solutions. The values of densities (ρ), refraction indexes (nD), isobaric heat capacities (Cp) and viscosities (η) were experimentally determined in the temperature range 278.15–323.15 K and at fullerenol concentrations up to 40 g·dm−3. For the highest fullerenol concentration (40 g·dm−3), density, viscosity and isobaric heat capacity modifications reach 4.5%, 56%, and 3%, respectively. Either temperature, T, and concentration, x, dependences of these physical properties were described by polynomial fittings or well-known expressions as the Vogel-Fulcher-Tamman equation, while T-x behaviors were described with the use of a second order polynomial function of both temperature and concentration (the standard deviations do not exceed 0.04). The dynamic and structural characteristics of (fullerene-water) and (fullerenol-water) binary systems were determined by using DFT and MD methods. Finally, the study was completed with the characterization of antioxidant activity of the fullerenol.