Effect of water hydrogen bonding on the solvent-mediated oscillatory repulsion of C₆₀ fullerenes in water

The solvent-mediated interaction of C₆₀ fullerenes in liquid water is examined by using the combination of the probabilistic hydrogen bond model with the density functional theory. This combination allows one to take into account the effect of hydrogen bonding between water molecules on their interaction with fullerenes and to construct an approximation for the distribution of water molecules in the system, which provides an efficient foundation for studying hydrophobic phenomena. Our numerical evaluations predict the solvent-induced interaction of two C₆₀ fullerenes in water at 293 K to have an oscillatory-repulsive character (previously observed in molecular dynamics simulations) only when the vicinal water-water hydrogen bonds are slightly weaker than bulk ones. Besides indicating the direction of the energetic alteration of water-water hydrogen bonds near C₆₀ fullerenes, our model also suggests that the hydrogen bonding ability of water plays a defining role in the solvent-mediated C₆₀-C₆₀ repulsion.