Physical properties of heavy-oxygen water. Absolute viscosity of H218O between 15 and 35°C

Abstract

The absolute viscosity of highly enriched heavy-oxygen water, HZ1'0, has been measured at 5°C intervals between 15 and 35"C, using a semi-automatic closed viscometer of the suspended-level type.A linear extrapolation was performed to determine the viscosity of 100 % heavy-oxygen water, based upon the measured viscosity of natural water and that of a highly enriched heavy-oxygen water sample. The effect of isotope substitution on the viscosity of natural water has been analyzed for both HZ1'0 and DZ160. The viscosity ratio at 25°C for Hz180/Hz160 is 1.0536, whereas that for Dz160/Hz160 is 1.2316.The viscosity of the different isotopic species of water may be useful in the elucidation of the structure of the liquid state. The effect of isotope substitution on liquid viscosity has been investigated almost exclusively for the case of the replacement of hydrogen by deuterium,l e.g., deuteroalcohols, deuterium substituted benzene and nitromethane. The viscosity of D2160 has been measured several times,2 most recently by Millero, et aL3 To the best of our knowledge, however, there is no report on the measurement of the viscosity of heavy-oxygen water.*The isotope effect may be analyzed by considering the relation of the viscosity to the molecular weight, molar volume and energy required to break the intermolecular bonds (van der Waals and hydrogen bonds), i.e., the energy of activation for viscous flow. During the course of the discussion, we will attempt to analyze the results using this approach. EXPERIMENTAL MATERIALSThe heavy-oxygen water sample (94.41 % l80) used in the experiments was produced in our Isotope Separation Plant. The water, produced initially as D2180, was converted (normalized) to H2180 as described by Steckel and S ~a p i r o . ~The purification of the H2180 sample was performed under high vacuum in order to prevent isotope exchange. The sample was distilled into a vessel containing some sodium in a glass tube.5 After the sodium had reacted, the solution was degassed and bromine was distilled into the reaction vessel. The resulting solution was kept a few days at room temperature. The purification procedure was completed with three non-ebullioscopic vacuum distillations of the sample from a vessel at room temperature to a vessel cooled in ice.* Since submission of the manuscript we have discovered a paper, I. B. Rabinovich and V. G .

Effect of2H and18O water isotopes in kinesin-1 gliding assay

“…The rate-limiting step in the gliding assay has not been explored as thoroughly, and it may be affected by surface-effects not observed in bulk or single-motor assays. We note that the proportional decrease in gliding speed is similar to the proportional reported increase in viscosity of the two pure isotopic solutions (Hardy & Cottington, 1949; Kudish, Wolf & Steckel, 1972). We did not attempt to measure the viscosity of any of our fractional mixtures.…”

Effect of 2-H and 18-O water isotopes in kinesin-1 gliding assay

“…The rate-limiting step in the gliding assay has not been explored as thoroughly, and it may be affected by surface-effects not observed in bulk or singlemotor assays. We note that the proportional decrease in gliding speed is similar to the proportional reported increase in viscosity of the two pure isotopic solutions [39][40]. We did not attempt to measure the viscosity of any of our fractional mixtures.…”

Dielectric response of light, heavy and heavy-oxygen water: isotope effects on the hydrogen-bonding network's collective relaxation dynamics

“…The substitution of hydrogen for deuterium in water has strong impact on its dynamic properties, such as viscosity, [1][2][3][4][5] translational and rotational self-diffusion, 5,6 resonance frequency of molecular vibrations, 5,7 echo decay time for hydrogen-bond vibrations obtained from Raman-terahertz (THz) spectroscopy, 8 as well as dipole-dipole correlation times measured by dielectric relaxation [9][10][11][12][13][14][15] and THz time-domain spectroscopies. [16][17][18] Relative to light water (H 2…”