On the role of short- and long-range forces in aqueous systems

Abstract

Effects of short- and long-range forces upon the properties of aqueous systems is examined using a decomposition into trial potentials which can be constructed from any realistic water-water potential. Both pure water and diluted aqueous solutions of nonelectrolytes are considered over a wide range of thermodynamic conditions. It is shown that, regardless of the thermodynamic conditions, the structure of water is determined by short range forces which may be both repulsive and attractive; however, with increasing temperature the effect of the short range attractive forces rapidly lessens. As regards the aqueous solutions of non-polar compounds, it is shown that only the short range water-water interactions and simple exclusion effects are essential for the arrangement and orientation of water molecules in the hydration shell.