Tracer diffusion coefficients of tritiated water and acetonitrile in water + acetonitrile mixtures

1980 ◽  
Vol 33 (8) ◽  
pp. 1667 ◽  
Author(s):  
AJ Easteal
Keyword(s):  
Diffusion Coefficients ◽  
Structural Model ◽  
Tritiated Water ◽  
Tracer Diffusion ◽  
Solution Viscosity ◽  
Composition Region ◽  
Self Diffusion ◽  
Composition Variation ◽  
Diaphragm Cell ◽  
Tracer Diffusion Coefficients

Tracer diffusion coefficients of tritiated water (HTO) and 14C-labelled acetonitrile have been measured at 298.15 K by the diaphragm cell method, for the whole range of compositions of water+ acetonitrile binary mixtures. The composition variation of (a) the deviation of D from additivity and (b) the product Dη, for each component, has been evaluated. The variation of Dη is discussed in terms of the Naberukhin- Rogov structural model for solutions of non-electrolytes in water. ��� The diffusion data have been used to test a semiempirical relationship, between solution viscosity and self-diffusion coefficients, due to Albright. For the composition region of 5-55 mole % acetonitrile Albright's equation gives calculated viscosities which agree well with observed values. The calculation fails to reproduce the observed variation of viscosity for the composition region of 60-95 mole % acetonitrile.

Prediction of Diffusion Coefficients in Liquid and Solids

2015 ◽  
Vol 364 ◽  
pp. 182-191 ◽  
Author(s):  
William Yi Wang ◽  
Bi Cheng Zhou ◽  
Jia Jia Han ◽  
Hua Zhi Fang ◽  
Shun Li Shang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
First Principles ◽  
Diffusion Coefficients ◽  
Tracer Diffusion ◽  
First Principles Calculations ◽  
Dominant Contribution ◽  
Creep Properties ◽  
Exchange Correlation ◽  
Self Diffusion ◽  
Tracer Diffusion Coefficients

Our activities in predicting diffusion coefficients in fcc, bcc, and hcp solid solutions using first-principles calculations and in liquid usingabinitiomolecular dynamics are reviewed. These include self-diffusion coefficients [1-4], tracer diffusion coefficients in dilute solutions [5-7], calculation of migration entropy [8], tracer diffusion coefficients in metallic and oxide liquid [9, 10], and effects of vacancy on diffusion of oxygen [11, 12]. The effects of exchange correlation functionals are examined in some cases along with charge transfer between solute and solvent elements. The dominant contribution of diffusion on the effects of Re addition on the creep properties of Ni-base superalloys is discussed [13].

Arsenic Diffusion in Intrinsic Gallium Arsenide

1998 ◽  
Vol 527 ◽  
Author(s):  
G. Bösker ◽  
N.A. Stolwijk ◽  
H. Mehrer ◽  
U. Södervall ◽  
J.V. Thordson ◽  
...  
Keyword(s):  
Gallium Arsenide ◽  
Mass Spectroscopy ◽  
Diffusion Coefficients ◽  
Nitrogen Doping ◽  
Tracer Diffusion ◽  
Substantial Contribution ◽  
Ambient Conditions ◽  
Self Diffusion ◽  
Tracer Diffusion Coefficients ◽  
Secondary Ion

ABSTRACTSelf-diffusion on the As sublattice in intrinsic GaAs was investigated in a direct way by As tracer diffusion measurements using the radioisotopes 73As and 76As and in an indirect way by annealing of buried nitrogen doping layers in epitaxially grown GaAs/GaAs:N heterostructures. The latter experiments were analyzed by secondary ion mass spectroscopy and interpreted within the framework of the kick-out mechanism yielding the As diffusivities mediated by As interstitials IAs. Comparison of with tracer diffusion coefficients – including data reported in the literature–points to a substantial contribution of IAs to As diffusion in intrinsic GaAs under As-rich ambient conditions.

Tracer diffusion in aqueous sucrose and urea solutions

1990 ◽  
Vol 68 (9) ◽  
pp. 1611-1615 ◽  
Author(s):  
Allan J. Easteal
Keyword(s):  
Diffusion Coefficients ◽  
Relative Viscosity ◽  
Tracer Diffusion ◽  
Proton Exchange ◽  
Specific Viscosity ◽  
Sucrose Solutions ◽  
Diaphragm Cell ◽  
Tracer Diffusion Coefficients ◽  
Viscosity Dependence

Tracer diffusion coefficients for water (as HTO), methanol (14CH3OH), and acetonitrile (CT3CN) in aqueous sucrose (10–25% w/w) and urea (0.25–4 mol L−1) solutions at 298 K have been determined using the diaphragm cell technique. For sucrose solutions tracer diffusion coefficients vary with the 2/3 power of the relative viscosity and the viscosity dependence is the same for the above tracers as for sucrose and oxygen. In urea solutions tracer diffusion coefficients appear to have a solute-specific viscosity dependence, but the solute specificity is largely removed when the effects of proton exchange and urea dimerisation are considered. Keywords: diffusion, water, methanol, acetonitrile, sucrose, urea.

scholarly journals Modelling the Diffusion Coefficients of Dilute Gaseous Solutes in Hydrocarbon Liquids

2021 ◽  
Vol 42 (10) ◽  
Author(s):  
Yasser A. Aljeshi ◽  
Malyanah Binti Mohd Taib ◽  
J. P. Martin Trusler
Keyword(s):  
Carbon Dioxide ◽  
Diffusion Coefficients ◽  
Hard Sphere ◽  
Tracer Diffusion ◽  
Pure Component ◽  
Viscosity Data ◽  
Polar Liquids ◽  
Self Diffusion ◽  
Coefficient Measurement ◽  
Tracer Diffusion Coefficients

AbstractIn this work, we present a model, based on rough hard-sphere theory, for the tracer diffusion coefficients of gaseous solutes in non-polar liquids. This work extends an earlier model developed specifically for carbon dioxide in hydrocarbon liquids and establishes a general correlation for gaseous solutes in non-polar liquids. The solutes considered were light hydrocarbons, carbon dioxide, nitrogen and argon, while the solvents were all hydrocarbon liquids. Application of the model requires knowledge of the temperature-dependent molar core volumes of the solute and solvent, which can be determined from pure-component viscosity data, and a temperature-independent roughness factor which can be determined from a single diffusion coefficient measurement in the system of interest. The new model was found to correlate the experimental data with an average absolute relative deviation of 2.7 %. The model also successfully represents computer-simulation data for tracer diffusion coefficients of hard-sphere mixtures and reduces to the expected form for self-diffusion when the solute and solvent become identical.

Non-Stoichiometry and Cation Tracer Diffusion Studies in the Magnetite-UlvÖSpinel Solution, (Fe,Ti)3-δO4

1994 ◽  
Vol 369 ◽  
Author(s):  
Sanjeev Aggarwal ◽  
Rudiger Dieckmann
Keyword(s):  
Diffusion Coefficients ◽  
Tracer Diffusion ◽  
Oxygen Activity ◽  
Spinel Solid Solution ◽  
Low Oxygen ◽  
Cation Diffusion ◽  
Deviation From Stoichiometry ◽  
Diffusion Studies ◽  
Tracer Diffusion Coefficients ◽  
Point Defect Structure

AbstractCation diffusion in the spinel solid solution (Fe1-xTix)3-δO4 (0≤ x ≤ 0.3) was investigated at 1200 ºC as a function of oxygen activity, aO2 and cationic composition, x. At different cationic compositions, cation tracer diffusion coefficients, D*Me of Me = Fe and Ti were measured as a function of oxygen activity. Plots of log DMe vs. loga0 show V-shaped curves, indicating that different types of point defects prevail at high anc low oxygen activities. Thermogravimetric experiments were conducted, using a high resolution microbalance, to determine the deviation from stoichiometry in (Fe1-xTix)3-δO4 at 1200 °C. δversus log aO2 curves are S-shaped. An analysis of the oxygen activity dependences of thecation diffusion coefficients and the deviation from stoichiometry with regardto the point defect structure suggests that at high oxygen activities cation vacancies are the predominant defects governing the deviation from stoichiometry and the diffusion ofcations. At low oxygen activities, and at small values of x, cation interstitials determine the deviation from stoichiometry, while they dominate for 0 ≤ x ≤ 0.3 inthe cation diffusion.

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