Diffusion Coefficients in Solution. An Improved Method for Calculating D as a Function of Concentration.

Eversole, W. G.; Peterson, Janerik; Kindsvater, H. M.

doi:10.1021/j150414a007

Cited by 9 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A further development of the BM method has been proposed by Eversole et al [47] for dilute solutions. They simply evaluated the integral term in Eq 3 by parts.…”

Section: Bm Methodsmentioning

confidence: 99%

Comparison of the Sauer-Freise and Hall Methods for Obtaining Interdiffusion Coefficients in Binary Alloys

Ahmed

Belova

Evteev

et al. 2015

J. Phase Equilib. Diffus.

View full text Add to dashboard Cite

In the present paper (1) the Hall method (HM) (specifically designed for determining the interdiffusion coefficient at the low and high composition limits of the corresponding interdiffusion composition profile) is further developed in order to be applied to the whole composition profile resulting in the Extended Hall method (EHM); (2) A comparative study of the HM, EHM, Boltzmann-Matano (BM) and Sauer and Freise (SF) methods is performed using composition profiles generated by computer simulation. The results clearly indicate that the HM/EHM technique is only applicable when the interdiffusion coefficient is constant (i.e. independent of composition) or almost constant at the low composition regions. In all other cases, the BM and SF methods give the best agreement with the input interdiffusion function even at the ends of the composition profiles.

show abstract

“…A further development of the BM method has been proposed by Eversole et al [47] for dilute solutions. They simply evaluated the integral term in Eq 3 by parts.…”

Section: Bm Methodsmentioning

confidence: 99%

Comparison of the Sauer-Freise and Hall Methods for Obtaining Interdiffusion Coefficients in Binary Alloys

Ahmed

Belova

Evteev

et al. 2015

J. Phase Equilib. Diffus.

View full text Add to dashboard Cite

show abstract

“…However, for more complex systems, the diffusion coefficient is a function of concentration, D = D ( C ). In order to calculate diffusion coefficients, Fick’s second law has been solved by different authors using analytical, , geometrical, − or mathematical approaches . Recently, a new geometrical method for estimation of the diffusion coefficient was developed based on the incorporation of the slope and intercept concepts into the integral representation of the diffusion equation .…”

Section: Concentration Dependant Diffusion Coefficient Calculationmentioning

confidence: 99%

Estimation of Diffusion Coefficients in Liquid Solvent–Bitumen Systems

2018

View full text Add to dashboard Cite

Solvent-based recovery processes have gained some advantage over thermal recovery processes under specific reservoir conditions. Solvent–bitumen mass transfer is a diffusion dominated process. The calculation of diffusion coefficients is fundamental for the design of solvent-based recovery processes as it allows us to understand the performance of the process. In a recent work, Babak et al. developed a new slopes and intercept method which was demonstrated to be very robust for the calculation of diffusion coefficients of binary systems. In this paper, the diffusion coefficients of dimethyl ether (DME), pentane, and toluene into two different bitumen systems are calculated using this method as a function of concentration. X-ray computed tomography (CT) is used to obtain the concentration profiles of the bitumen–solvent systems. Furthermore, a new modification of Vignes’ equation is introduced to predict concentration-dependent diffusion coefficients. This new modification includes the acceleration and deceleration parameter associated with the solvent and bitumen mass transfer behavior. The developed equation successfully predicts the diffusion coefficients of the studied systems.

show abstract

Überspannung und Gleichgewichtspotentiale der Methylenblau/Leukomethylenblau–Redoxelektrode

Vetter

Bardeleben

1957

Zeitschrift für Elektrochemie, Berichte der Bunsengesellschaft

View full text Add to dashboard Cite

Abweichungen des Gleichgewichtspotentials von dem Potential, das sich unter Verwendung der analytischen Konzentrationen nach der Nernstschen Gleichung ergibt, werden auf die Dimerisierung des Methylenblaus zurückgeführt und die Dimerisierungskonstante in Übereinstimmung mit dem Wert, der aus dem Absorptionsspektrum abgeleitet wird, zu K = 2,6 · 103 Mol−1 · Ltr ermittelt.Die anodische und kathodische Überspannung wird in Abhängigkeit von der Konzentration in einem Bereich von c = 2 · 10−3 bis 5 · 10−6 Mol/Ltr mit Gleichstrom gemessen und als reine Diffusionsüberspannung erkannt. Eine Ermittlung des Reaktionsmechanismus ist daher nicht möglich.Die nicht proportionale Abhängigkeit der kathodischen Diffusionsgrenzstromdichten von der Methylenblau‐Konzentration, die sich in einer mit wachsender Konzentration kleiner werdenden Diffusionskonstante ausdrücken läßt, wird ebenfalls auf die Dimerisierung zurückgeführt. Es wird die Konzentrationsabhängigkeit dieser scheinbaren Diffusionskonstanten unter Voraussetzung des stets eingestellt bleibenden Dimerisierungsgleichgewichts abgeleitet und experimentell mit K = 3,1 · 103 Mol−1 · Ltr, D1 = 7,6 · 10−6 cm2 · s−1 (monomer), D2 = 0,95 · 0,95 · 10−6 cm2 · s−1 (dimer) bestätigt. Die kompliziertere Abhängigkeit der Diffusionsüberspannung von der Stromdichte wird berechnet und mit den experimentellen Werten in Übereinstimmung gefunden. Trotz des Ablaufs einer chemischen Reaktion innerhalb der Diffusionsschicht soll definitionsgemäß keine Reaktionsüberspannung vorliegen, da alle chemischen Gleichgewichte eingestellt bleiben.

show abstract

Diffusion Coefficients in Solution. An Improved Method for Calculating D as a Function of Concentration.

Abstract: 1. The method proposed by Eversole Doughty for the calculation of diffusion coefficients is in error except at the lowest concentrations.2. A new equation is derived which expresses D as a function of concentration for all concentrations.

Cited by 9 publications

References 2 publications

Comparison of the Sauer-Freise and Hall Methods for Obtaining Interdiffusion Coefficients in Binary Alloys

Comparison of the Sauer-Freise and Hall Methods for Obtaining Interdiffusion Coefficients in Binary Alloys

Estimation of Diffusion Coefficients in Liquid Solvent–Bitumen Systems

Überspannung und Gleichgewichtspotentiale der Methylenblau/Leukomethylenblau–Redoxelektrode

Contact Info

Product

Resources

About