The Dielectric Properties of Water in Solutions

Abstract

Results of dielectric constant and loss measurements at λ=9.22, 3.175, and 1.264 cm are given for a wide variety of aqueous solutions of ions and organic molecules. The water relaxation time is shortened by positive ions and lengthened by hydrogen bond-forming molecules. The properties of water are treated by a statistical method in which the numbers of molecules in four, three, two, one, and zero-bonded states are estimated from dielectric and latent heat data. Fair agreement with experiment is obtained in calculating the static dielectric constant of ice at 0° and water from 0–370°C, using Kirkwood's dielectric theory and Verwey's calculation of the dipole moment of a four-bonded water molecule. The effects of temperature and solutes on the water relaxation time are discussed in terms of this statistical method. The effective number of water molecules ``irrotationally bound,'' i.e., prevented from turning in the electric field by the ion or the organic molecule, is estimated from the depression of the low frequency dielectric constant, using a dielectric theory of mixtures. This number is zero for uncharged solute molecules but is finite for organic or inorganic ions.

Hydrogen Bond Interactions Between Water Molecules in Bulk Liquid, Near Electrode Surfaces and Around Ions

“…Average number of H bonds per water molecule at various temperatures, as extracted using different techniques in the past. X ray diffraction study at 100 MPa (Gorbaty & Demianets, 1983); NMR (Hoffmann & Conradi, 1997); Water electronic study (Schwegler et al, 2000); Quantum cluster equilibrium method (Lehmann et al, 2009); TIP4P (Prendergast & Galli, 2006); + CPAIMD (Lee & Tuckerman, 2006); ♦ Neutron diffraction (Soper et al, 1997); IR (Luck, 1967); TEY-NEXAFS (Smith et al, 2004); SXEER (Myneni et al 2002); IR at 250 atm (Bondarenko & Gorbaty, 1991); Latent Heat (Haggis et al, 1952); Statistical mechanics (Suresh et al, 2000); Electronic structure study (He et al 2007 (Kalinichev & Bass, 1997); Ab initio (Kuo & Mundy, 2004); FPMD (Hetenyi et al, 2004); X-ray absorption (Wernet et al, 2004). We first start with a discussion on the paper published by Smith et al (Smith et al, 2004) which concluded that HB n   ~3.3.…”

Ionic Equilibria in Mixed Solvents. IV. Solvent Effect on Dissociation Constants of Acids

“…(1). Thus, the dissociation equilibrium of ammonium ion in a waternmethanol mixture is described as: (7) Here x denotes a fraction of alkoxonium ion formed and is given by the following equation through the equilibrium constant, k, of Eq. (1): (8) activities of water and methanol being approximated to be equal to their mole fractions.…”

Influence of cancer disease on dielectric characteristics of structural-functional state of erythrocyte membranes

“…For this factor can be separated the specific component of influence that is the change of phase-structural state of membrane [19][20][21]. The structural reconstructions of erythrocyte membranes induced by the temperature cause the changes of solvent (water) structure [22,23]. The possibility of the use of UHF-dielectrometry method for the study of relaxation frequency of substances particularly the dielectric relaxation frequency of the water molecules in erythrocyte membranes is determined by the fact that the molecules of the bound water and dissolved substance in centimeter wavelengths diaposon are less movable than the molecules of the free water [24,25].…”