Dielectric Relaxation of Water in Complex Systems

Abstract

Whenever water interacts with another dipolar or charged entity, a broadening of the dielectric relaxation peak occurs. This broadening can often be described by the phenomenological Cole-Cole (CC) spectral function. A new approach (Puzenko AA, Ben Ishai P, and Feldman Y, Phys Rev Lett 105:037601, 2010) based on the fractal nature of the time set of the interaction of the relaxing water dipoles with its encompassing matrix has been recently presented showing a fundamental connection between the relaxation time, τ, the broadening parameter, α, and the Kirkwood-Fröhlich correlation function B. Parameters B, τ and α where chosen as the coordinates of a new 3D space. The evolution of the relaxation process due to the variation of external macroscopic parameters (temperature, pressure etc.) represents the trajectory in 3D space. This trajectory demonstrates the connection between the kinetic and structural properties of the water in complex system. It is also shown how the model describes the state of water in two porous silica glasses and in two different types of aqueous solutions: ionic, and non-ionic. The complex dielectric spectra of a series of solutions of sodium chloride and potassium chloride in water have been measured and have been carefully analyzed along with previously measured spectra for aqueous solutions of D-glucose and D-fructose.