Physicochemical Properties of Structured Water at Material Surfaces

Abstract

Physicochemical properties of thin film water on and between material surfaces have been reviewed. Infrared (IR) spectroscopy on thin film water sandwiched between various materials showed shifts of OH stretching vibration frequency maxima from 3400 cm−1 to about 3250 cm−1. These shifts vary with different materials, crystallographic orientations, film thickness (less than about 200 nm), dissolved ions and temperatures. The thin film water is supposed to have constrained structure close to ice and might have smaller diffusion coefficients and larger viscosity than the bulk liquid water. Standard molar volume, specific heat and entropy values for hydration water on some inorganic materials are different from these for the bulk liquid water and close to those for ice polymorphs. Sonic wave velocity measurements on a water-saturating rock suggest a larger P wave velocity for the thin film water than the value for bulk water. These structured thin water films with different properties from those of the bulk water can be present in the earth's interior and also in living materials such as cactus and human skin controlling dynamics of earth and life.