Kinetics of formation of sodium chlorozirconate

1967 ◽  
Vol 45 (20) ◽  
pp. 2317-2320 ◽  
Author(s):  
J. D. Dutrizac ◽  
S. N. Flengas
Keyword(s):  
Rate Constant ◽  
Parabolic Rate Constant ◽  
Zirconium Tetrachloride ◽  
Formation Reaction ◽  
Diffusion Controlled ◽  
Kinetics Of Formation ◽  
Torr Pressure ◽  
Arrhenius Rate Equation ◽  
Kinetics Of ◽  
Method Analysis

The kinetics of formation of sodium hexachlorozirconate from sodium chloride single crystals and zirconium tetrachloride vapor at about 600 Torr have been investigated by the weight-gain method. Analysis of the results showed the formation reaction to be diffusion controlled, with zirconium tetrachloride being the most probable diffusing species. The apparent energy of activation has been determined for this reaction from the variation of the rate constant with temperature, and it was found to be 12.3 ± 3 kcal/mole. The Arrhenius rate equation for the formation of Na2ZrCl6 from NaCl and ZrCl4 at 600 Torr pressure, in the temperature range 400 to 500 °C, is [Formula: see text]where the units of the parabolic rate constant, K, are (g(Na2ZrCl6))2 cm−4 h−1.

Joining of Ti3SiC2 with Ti–6Al–4V Alloy

2002 ◽  
Vol 17 (1) ◽  
pp. 52-59 ◽  
Author(s):  
N.F. Gao ◽  
Y. Miyamoto
Keyword(s):  
Solid State ◽  
Rate Constant ◽  
Liquid State ◽  
Parabolic Rate Constant ◽  
Diffusion Path ◽  
Solid State Diffusion ◽  
Diffusion Controlled ◽  
State Diffusion ◽  
Rate Controlled ◽  
Higher Temperature

The joining of a Ti3SiC2 ceramic with a Ti–6Al–4V alloy was carried out at the temperature range of 1200–1400 °C for 15 min to 4 h in a vacuum. The total diffusion path of joining was determined to be Ti3SiC2/Ti5Si3Cx/Ti5Si3Cx + TiCx/TiCx/Ti. The reaction was rate controlled by the solid-state diffusion below 1350 °C and turned to the liquid-state diffusion controlled with a dramatic increase of parabolic rate constant Kp when the temperature exceeded 1350 °C. The TiCx tended to grow at the boundarywith the Ti–6Al–4V alloy at a higher temperature and longer holding time. TheTi3SiC2/Ti–6Al–4V joint is expected to be applied to implant materials.

Pressure Effect on the Kinetics of Reaction Between Solid NaCl and ZrCl4 or HfCl4 Vapors

1971 ◽  
Vol 49 (17) ◽  
pp. 2885-2890 ◽  
Author(s):  
P. Pint ◽  
S. N. Flengas
Keyword(s):  
Sodium Chloride ◽  
Single Crystals ◽  
Constant Temperature ◽  
Pressure Effect ◽  
Heterogeneous Reaction ◽  
Zirconium Tetrachloride ◽  
Hafnium Tetrachloride ◽  
Diffusion Controlled ◽  
Kinetics Of Reaction ◽  
Kinetics Of

The kinetics of reaction between single crystals of sodium chloride and zirconium tetrachloride and hafnium tetrachloride vapors, to form sodium hexachlorozirconate and sodium hexachlorohafnate, respectively, have been investigated as a function of the tetrachloride pressures at a constant temperature of 485 °C. The rate of formation of Na2ZrCl6 is kinetically more favorable. The heterogeneous reaction is diffusion controlled, with the rate of diffusion depending on the availability of Cl− vacancies.

scholarly journals An Empirical Rate Constant Based Model to Study Capacity Fading in Lithium Ion Batteries

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Srivatsan Ramesh ◽  
K. Venkata Ratnam ◽  
Balaji Krishnamurthy
Keyword(s):  
Rate Constant ◽  
Film Formation ◽  
Solid Electrolyte Interphase ◽  
Lithium Ion ◽  
Capacity Fading ◽  
Formation Reaction ◽  
One Dimensional ◽  
Battery Systems ◽  
Diffusion And Kinetics ◽  
Kinetics Of

A one-dimensional model based on solvent diffusion and kinetics to study the formation of the SEI (solid electrolyte interphase) layer and its impact on the capacity of a lithium ion battery is developed. The model uses the earlier work on silicon oxidation but studies the kinetic limitations of the SEI growth process. The rate constant of the SEI formation reaction at the anode is seen to play a major role in film formation. The kinetics of the reactions for capacity fading for various battery systems are studied and the rate constants are evaluated. The model is used to fit the capacity fade in different battery systems.

COMPARATIVE STUDY ON THE ADSORPTION PROCESSES OF ALKANETHIOL AND ALKANEDITHIOL ON GOLD

2010 ◽  
Vol 17 (04) ◽  
pp. 397-403 ◽  
Author(s):  
HUI HE ◽  
YAN GUO ◽  
SHOUFU WANG ◽  
YAQING JIANG
Keyword(s):  
Self Assembly ◽  
Surface Coverage ◽  
Self Assembled Monolayers ◽  
Diffusion Controlled ◽  
Assembled Monolayers ◽  
Adsorption Processes ◽  
Kinetics Of Formation ◽  
Initial Adsorption ◽  
Adsorption Rates ◽  
Kinetics Of

The kinetics of formation of self-assembled monolayers on gold generated by the adsorption of 1-octanethiol and 1,8-octanedithiol were explored by electrochemistry measurement. The time dependence of capacitance and surface coverage supported that the adsorption of thiols typically processed with a two-step adsorption consisted of a fast initial adsorption and a slowly following reorganization. From the function of surface coverage versus time, one could get rate constants of adsorption of thiols, and the adsorption process was demonstrated to follow a diffusion-controlled Langmuir model. A comparison of the adsorption rates for different concentration between 1-octanethiol and 1,8-octanedithiol revealed that their adsorption processes were almost identical and independent on the concentration, inferring that only one sulfur atom contributed to the self-assembly of dithiol molecule.

Formation kinetics of nanocrystalline Fe–4 wt.% Al solid solution during ball milling

1997 ◽  
Vol 12 (6) ◽  
pp. 1429-1432 ◽  
Author(s):  
H. G. Jiang ◽  
R. J. Perez ◽  
M. L. Lau ◽  
E. J. Lavernia
Keyword(s):  
Solid Solution ◽  
Ball Milling ◽  
Structural Evolution ◽  
Milling Process ◽  
Avrami Equation ◽  
Scanning Calorimetry ◽  
Diffusion Controlled ◽  
Interphase Boundaries ◽  
Kinetics Of Formation ◽  
Kinetics Of

Formation of nanocrystalline Fe–4 wt.% Al solid solution has been achieved through SPEX ball milling of blended elemental Fe and Al powders. Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) have been employed to follow the structural evolution during the ball-milling process. Exothermic peaks exhibited in DSC diagrams of the powders milled for 10 to 60 min yielded thermal enthalpies corresponding to the formation of Fe–4 wt.% Al solid solution, from which the kinetics of formation were found to follow the Johnson–Mehl–Avrami equation. Assessment of the kinetic parameter n reveals a diffusion controlled mechanism, in which grain and interphase boundaries may play a crucial role, during the solid solution formation of Fe–4 wt.% Al.

Kinetics of the Anation Reaction of Nickel(II) and 1,10-Phenanthroline in Ethanol

1972 ◽  
Vol 50 (23) ◽  
pp. 3861-3865 ◽  
Author(s):  
M. L. Sanduja ◽  
W. MacF. Smith
Keyword(s):  
Rate Constant ◽  
Sodium Perchlorate ◽  
Order Rate Constant ◽  
Stopped Flow ◽  
Tetrabutyl Ammonium ◽  
Kinetics Of Formation ◽  
Kinetics Of ◽  
Nickel Perchlorate ◽  
Anation Reaction ◽  
Made In

The kinetics of formation of the monophenanthroline complex of nickel(II) in ethanol has been studied using stopped-flow methods over the temperature range 7 to 35 °C. Tetrabutyl ammonium perchlorale in concentration 0.044 M does not affect the rate appreciably, sodium perchlorate at the same concentration depresses the rate significantly. Most measurements were made in the absence of electrolytes other than nickel perchlorate and a trace of perchloric acid. The second order rate constant is not significantly dependent on the nickel(II) concentration over a four-fold change in value indicating that the concentration of encounter pairs is small relative to the concentration of the free reactants. The rate constant at 25 °C (31 × 103 M−1 s−1)is consistent with a dissociative interchange mechanism and the rate constant for ethanol exchange on nickel. However, the value of ΔH≠ for the overall reaction (15.9 ± 1.0 kcal mol−1) is about 5 kcal mol−1 higher than that reported for ethanol exchange.

scholarly journals The kinetics of effector binding to phosphofructokinase. The binding of Mg2+-1,N6-ethenoadenosine triphosphate to the catalytic site

1980 ◽  
Vol 189 (3) ◽  
pp. 561-567 ◽  
Author(s):  
D Roberts ◽  
G L Kellett
Keyword(s):  
Skeletal Muscle ◽  
Cyclic Amp ◽  
Rate Constant ◽  
Catalytic Site ◽  
Stopped Flow ◽  
Diffusion Controlled ◽  
Inhibitory Site ◽  
Kinetics Of ◽  
Step Mechanism ◽  
Effector Binding

1. The binding of the fluorescent ATP analogue, Mg2+-1,N6-etheno-ATP, to the catalytic site of rabbit skeletal muscle phosphofructokinase has been studied by stopped-flow fluorimetry [Roberts & Kellet (1979) Biochem. J. 183, 349–360]. 2. Binding of Mg2+-1,N6-etheno-ATP to the catalytic site is consistent with a two-step mechanism of the type: (formula: see text); in which the diffusion-controlled binding of ligand, L, is accompanied by prior interconversion of enzyme from one form, E, to another, E. 3. The allosteric activators, phosphate and cyclic AMP, which promote an R-type conformation, appear to stabilize slightly different conformations, R and R' respectively. 4. The binding of Mg2+-1,N6-etheno-ATP to the catalytic site is strongly affected by its binding to the inhibitory site. The rate constant for the displacement of Mg2+-1,N6-ethenol-ATP from the catalytic site, k32, is 470 +/- 35 s-1 for the R' conformation, whereas it is 6.0 +/- 0.09 s-1 for the T conformation induced by binding of Mg2+-1,N6-ethenol-ATP to the inhibitory site.

Kinetics of the anation reaction of nickel(II) and 1,10-phenanthroline in methanol–water mixtures

1969 ◽  
Vol 47 (20) ◽  
pp. 3773-3778 ◽  
Author(s):  
M. L. Sanduja ◽  
W. MacF. Smith
Keyword(s):  
Ionic Strength ◽  
Rate Constant ◽  
Rate Constants ◽  
Solvent Composition ◽  
Solvent Mixtures ◽  
Methanol Content ◽  
Dependent Rate ◽  
Kinetics Of Formation ◽  
Kinetics Of ◽  
Anation Reaction

The kinetics of formation of the monophenanthroline complex of nickel(II) has been studied spectrophotometrically in water–methanol mixtures of 0 to 97 weight % of methanol, at ionic strength 0.050, at varying acidities at 25 °C. Values for the rate constants for the acid independent and acid dependent reactions together with values for the equilibrium acid ionization quotient of phenanthrolium ion over the range of solvent mixtures have been determined. The values of the acid independent rate constant show little dependence on solvent compositions up to 76% methanol, then decrease and show no correlation with trends in the ionization quotient of phenanthrolium ion. The acid dependent rate constant shows only a modest dependence on solvent composition over most of the range of solvent compositions except in the range of highest methanol content where it is not significantly different from zero.

Thermal behaviour and kinetics of formation reaction of the synthetic analogue of pääkkonenite, Sb2AsS2

1996 ◽  
Vol 8 (3) ◽  
pp. 639-648 ◽  
Author(s):  
Gian Piero Bernardini ◽  
Daniele Borrini ◽  
Fernando Corsini ◽  
Cοstanza Danti ◽  
Giulio G.T. Guarini ◽  
...  
Keyword(s):  
Thermal Behaviour ◽  
Synthetic Analogue ◽  
Formation Reaction ◽  
Kinetics Of Formation ◽  
Kinetics Of
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