Thermodynamic properties and self-diffusion of molten sodium chloride. A molecular dynamics study

1975 ◽  
Vol 71 ◽  
pp. 41 ◽  
Author(s):  
John W. E. Lewis ◽  
Konrad Singer
Keyword(s):  
Molecular Dynamics ◽  
Sodium Chloride ◽  
Thermodynamic Properties ◽  
Self Diffusion ◽  
Molten Sodium

Self-diffusion in molten sodium chloride: a test of the applicability of the Nernst—Einstein equation

1957 ◽  
Vol 241 (1227) ◽  
pp. 554-567 ◽  
Keyword(s):  
Sodium Chloride ◽  
Einstein Equation ◽  
Diffusion Coefficients ◽  
Liquid Sodium ◽  
Einstein Relation ◽  
Transport Numbers ◽  
Self Diffusion ◽  
Capillary Method ◽  
Molten Sodium ◽  
The Individual

Self-diffusion coefficients of sodium and chlorine in molten sodium chloride have been determined by the capillary method with the aid of 22 Na and 36 Cl radio-tracers. The results can be represented by the expressions D Na = 8x 10 -4 exp (-4000/RT) and D Cl = 33 x 10 -4 exp (-8500/.RT). These values, when inserted in the Nernst-Einstein equation (A = (F 2 /RT) (D+ D-)), lead to a value of the equivalent conductance, A, which is about 40 % greater than that observed experimentally. The evidence that the diffusion coefficients of Na + and Cl - are similar in magnitude and that the activation energies are much smaller than the heat of vaporization of liquid sodium chloride, support the conclusions, derived from other evidence, that the free volume in the molten salt consists largely of holes, analogous to vacant lattice sites. On the basis of this model, the discrepancy in the Nernst-Einstein relation can readily be interpreted in terms of two diffusion mechanisms, one being normal vacancy diffusion of single ions, and the other a process in which no net charge is displaced in a unit step. It is suggested that the latter is the Seitz-Dienes mechanism of consecutive jumps of cation and anion in coupled vacancies. The interpretation mentioned enables the individual mobilities of Na + and Cl - ions to be determined, and hence their transport numbers can be calculated (t Na += 0.71, t Cl - = 0.29 at 935° C). The individual diffusion coefficients of the ions and of the coupled vacancies are in reasonable agreement with the Stokes-Einstein equation.

Molecular dynamics simulation of interhalogen compounds. 1. Liquid chlorine trifluoride (ClF3): structure and thermodynamics

1992 ◽  
Vol 70 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Ramesh K. Wadi ◽  
Vivek Saxena
Keyword(s):  
Molecular Dynamics ◽  
Thermodynamic Properties ◽  
Md Simulation ◽  
Pair Potential ◽  
Liquid Structure ◽  
Spectroscopic Studies ◽  
Distribution Functions ◽  
Dynamics Simulation ◽  
Self Diffusion ◽  
Laser Raman

The results of a molecular dynamics (MD) simulation study of liquid chlorine trifluoride (ClF3) at 217, 260, and 287 K are reported. The cubic simulation cell consists of 108 ClF3 molecules assumed to be interacting via site–site Lennard–Jones 12–6 pair potential. The parameters for F–F and Cl–Cl interaction are the same as used for the simulation of F2, and Cl2, respectively, and those for the Cl–F cross interaction are calculated using Lorentz–Berthelot rules. These results are then used to calculate various radial distribution functions characteristic of the liquid structure. Thermodynamic properties, namely, configurational energy, constant volume specific heat, and internal pressure are also reported. The time-dependent properties, mean square force and torque, self diffusion coefficient, and the quantum corrections to the free energy, were also obtained. The dimer configuration drawn based on the observed contact distances was found to be in good agreement with the results of matrix isolation infrared and laser Raman spectroscopic studies. Keywords: MD simulation, interhalogens, liquid structure, thermodynamic properties.

Some Properties of Molten KCl at High Density Studied by MD Simulation

1981 ◽  
Vol 36 (10) ◽  
pp. 1106-1111 ◽  
Author(s):  
Ryuzo Takagi ◽  
Isao Okada ◽  
Kazutaka Kawamura
Keyword(s):  
Molecular Dynamics ◽  
Monte Carlo ◽  
Thermodynamic Properties ◽  
Diffusion Coefficients ◽  
Md Simulation ◽  
Ambient Pressure ◽  
The Self ◽  
Self Diffusion ◽  
Dynamics Simulations ◽  
Good Agreement

Molecular dynamics simulations of molten KCl have been performed at 1173 K with the molar volumes of 52.0 (the value under ambient pressure), 50.0, 48.0 and 45.0 cm3 mol-1 . Some thermodynamic properties at higher densities have been evaluated, which are generally in good agreement with the experimentally obtained ones and Monte Carlo results. Both at normal and higher densities, the self-exchange velocities of neighbouring unlike ions (SEV) are found to be proportional to the internal mobilities with nearly the same constant as derived previously for molten LiCl, RbCl and their 1 : 1 mixture. Calculated transport properties such as the SEV and the self-diffusion coefficients considerably decrease with increasing density, while the configuration does not change much.

scholarly journals Molecular Dynamics Simulation on the Interaction between Palygorskite Coating and Linear Chain Alkane Base Lubricant

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 286
Author(s):  
Jin Zhang ◽  
Lv Yang ◽  
Yue Wang ◽  
Huaichao Wu ◽  
Jiabin Cai ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Structural Changes ◽  
Molecular Diffusion ◽  
Linear Chain ◽  
Interfacial Interaction ◽  
Dynamics Simulation ◽  
Electrostatic Energy ◽  
Experimental Development ◽  
Practical Applications ◽  
Self Diffusion

Molecular dynamics (MD) simulations were conducted to investigate the interactions between a palygorskite coating and linear chain alkanes (dodecane C12, tetradecane C14, hexadecane C16, and octadecane C18), representing base oils in this study. The simulation models were built by placing the alkane molecules on the surface of the palygorskite coating. These systems were annealed and geometrically optimized to obtain the corresponding stable configurations, followed by the analysis of the structural changes occurring during the MD process. The interfacial interaction energies, mean square displacements, and self-diffusion coefficients of the systems were evaluated to characterize the interactions between base lubricant molecules and palygorskite coating. It was found that the alkanes exhibited self-arrangement ability after equilibrium. The interfacial interaction was attractive, and the electrostatic energy was the main component of the binding energy. The chain length of the linear alkanes had a significant impact on the intensity of the interfacial interactions and the molecular diffusion behavior. Moreover, the C12 molecule exhibited higher self-diffusion coefficient values than C14, C16 and C18. Therefore, it could be the best candidate to form an orderliness and stable lubricant film on the surface of the palygorskite coating. The present work provides new insight into the optimization of the structure and composition of coatings and lubricants, which will guide the experimental development of these systems for practical applications.

scholarly journals Self-diffusion of Fe and Pt in L1-Ordered FePt: Molecular Dynamics simulation

2021 ◽  
Vol 192 ◽  
pp. 110337
Author(s):  
S.I. Konorev ◽  
R. Kozubski ◽  
M. Albrecht ◽  
I.A. Vladymyrskyi
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Self Diffusion
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