Temperature dependence of solvent structure around a hydrophobic solute: A Monte Carlo study of methane in water

Monte Carlo simulations of methane in water were conducted in the (NpT) ensemble between 255 and 390 K. The structural properties of water around the solute are compared with those of bulk water. Water-water interactions are examined in three regions: the bulk solvent, the hydration shell and across the shell-bulk interface. There is evidence that water-water ordering increases in the shell and decreases across the interface. Differences between shell and bulk hydrogen-bond energies and binding energies are evaluated as functions of temperature and their relevance to hydrophobic aggregation is discussed.