Dielectric constant of deuterium oxide

Abstract

. An equal ratio-arm, capacitance-con ductance bridge operated at frcq ue ncie below 100 kilocycles per sccond was used to meas ure t he dielec tric constant of de uterium ox ide wi Lh an accuracy of 0.1 percent or better in t he range 4° to 100° C. A val ue of 77 .9-l was found for the dielectric cons tant a t 25° C. The data fi t t he relation . = 87.482 -(OA 0509)t + (9.638 X 10-4 )12 -(1.333 X 10-6 )13, with a maximum de viation of less than 0.01 uni t in di electri c co nstan t . These val ues we re obtained by using a sample ha\ ing a deuterium ox ide content of 99.38 mole percent. D eviation of t hese values from those for pure de uterium oxide, as a res ult of isotopic contamination, is estimated to b e less t han 0.005 unit. So me aspects of the t emperatme depe ndence of the dielectric constant and of that of a mac roscopic pola ri zation are disc ussed .

The Effect of Lipopolysaccharide Core Oligosaccharide Size on the Electrostatic Binding of Antimicrobial Proteins to Models of the Gram Negative Bacterial Outer Membrane

“…The membrane charges originate from the phosphate groups present within the inner core region of the OM mimics. The Debye screening length is calculated using eq 1 : ε r is the dielectric constant; here we used a combination of the dielectric constants of D 2 O 41 and polysaccharides (a value of 3.3 was used, this assumes the uncharged sugars have a similar dielectric constant to sucrose) times the relative volume fractions each component occupied within the core regions based on volume fractions obtained from the NR data fits. ε 0 is vacuum permittivity, R is the gas constant, T is the temperature (293 K in the case of these measurements), F is Faraday’s constant, and C is the concentration of a monovalent salt solution (in mol/m 3 ).…”

Effect of H2O and D2O Thermal Anomalies on the Luminescence of Eu3+ Aqueous Complexes

“…The reason for considering also deuterated water solutions is double: (i) O-H vibrations strongly quench the Eu 3+ emission spectrum, while O-D vibrations do not; and (ii) experimental evidence also exists of a structural crossover in D2O. 13,24 We here show how certain luminescent features of Eu 3+ ions (branching ratios and radiative and non-radiative transition rates) are affected by the water structural crossover. In addition, the 5 D0 → 7 F0 emission band, which is sensitive to the presence of different environments (i.e.…”

Fully quantum calculation of the second and third virial coefficients of water and its isotopologues fromab initiopotentials

“…For example, one can expect that properties depending more directly on strength of interactions, like enthalpy of vaporization or heat capacity, will be affected more, while a quantity like liquid density that depends mainly on molecular size will be affected less, which indeed seems to be the case. Some information about the expected size of nuclear-motion quantum effects can be inferred from accurately known data on D 2 O vs. H 2 O at 300 K: molar density of liquid D 2 O is 0.3% smaller, 61,89 dielectric constant of liquid is 0.5% smaller, 90,91 molar heat capacity of liquid is 11% larger, 61,89 enthalpy of vaporization is 3.3% larger, 61,89 and second virial coefficient is 8% larger in magnitude (Tables 1 and 2). All these trends are in line with the expected effects on various properties due to quantum weakening of intermolecular interactions.…”