scholarly journals PFG-NMR and MD Simulation Study of Self-Diffusion Coefficients of Binary and Ternary Mixtures Containing Cyclohexane, Ethanol, Acetone, and Toluene

2021 ◽  
Author(s):  
Daniel Bellaire ◽  
Hendrik Kiepfer ◽  
Kerstin Münnemann ◽  
Hans Hasse
Keyword(s):  
Experimental Data ◽  
Diffusion Coefficients ◽  
Molecular Model ◽  
Ambient Pressure ◽  
Ternary Mixtures ◽  
Self Diffusion ◽  
Field Gradients ◽  
Binary And Ternary Mixtures ◽  
Pfg Nmr ◽  
Good Agreement

Recently, Guevara-Carrion et al. published a comprehensive molecular dynamics (MD) study on the thermodynamic properties of binary mixtures containing methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride which also includes results on self-diffusion coefficients. However, for the mixtures acetone/cyclohexane, acetone/ethanol, acetone/toluene, cyclohexane/ethanol, and toluene/ethanol, no experimental data on self-diffusion coefficients were available for comparison. Therefore, in the present work, self-diffusion coefficients in these mixtures were measured by 1H NMR spectroscopy using pulsed field gradients (PFGs) at 298.15 K and ambient pressure. The experimental data were compared to the simulations of Guevara-Carrion et al. Good agreement was observed for all mixtures that do not contain ethanol, whereas, for ethanol-containing mixtures, the deviations were larger. This finding is attributed to deficiencies of the molecular model in describing the hydrogen-bonding of ethanol. Furthermore, self-diffusion data for the ternary mixture acetone/toluene/cyclohexane were measured and compared to molecular simulation data from the present work. Good agreement was observed.

scholarly journals Surface tension of O2-Ar, N2-Ar and O2-N2-Ar mixtures

2019 ◽  
pp. 21-27
Author(s):  
Mauricio García-Martínez ◽  
Benjamín Ibarra-Tandi ◽  
Daniel Porfirio Luis-Jiménez ◽  
Jorge López-Lemus
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Force Fields ◽  
Ternary Mixtures ◽  
Binary And Ternary Mixtures ◽  
Experimental Surface ◽  
Argon Mixture ◽  
Dynamics Simulations ◽  
Tension Curves ◽  
Good Agreement

The surface tension of some binary and ternary mixtures was calculated by means of molecular dynamics simulations in a canonical set. The analyzed mixtures were oxygen-argon, nitrogen-argon and oxygen-nitrogen-argon. The force field for argon was recalculated in order to reproduce the experimental surface tension. The corresponding force fields for O2 and N2 were taken from a previous work [Mol. Simul. 45 (2019) 958-966], where it was shown that such force fields reproduce the experimental surface tension curves, as pure fluids. The nitrogen-argon surface tension was calculated for several mole fractions of argon. The obtained curve was compared with those experimental data and a good agreement was found. The standard Lorentz-Berthelot combining rules were employed. For the oxygen-argon mixture it was necessary to modify the cross term of the combining rules in order to reproduce theoretical and experimental data. The surface tension of the ternary mixture was also estimated varying the mole fraction of argon at a certain concentration of oxygen and nitrogen, previously adjusted. Several temperatures were used in order to show a tendency mostly at relatively low temperatures. After comparing the available experimental data, which are scarce, a good agreement was observed.

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.

Properties of Refrigerants from Cubic Equations of State

2008 ◽  
Vol 59 (5) ◽  
Author(s):  
Viorel Feroiu ◽  
Dan Geana ◽  
Catinca Secuianu
Keyword(s):  
Experimental Data ◽  
Vapor Pressure ◽  
Equations Of State ◽  
Ternary Mixtures ◽  
Volumetric Properties ◽  
Mixing Rules ◽  
Saturation Curve ◽  
Equilibrium Thermodynamic ◽  
Liquid Equilibrium ◽  
Binary And Ternary Mixtures

Vapour � liquid equilibrium, thermodynamic and volumetric properties were predicted for three pure hydrofluorocarbons: difluoromethane (R32), pentafluoroethane (R125) and 1,1,1,2 � tetrafluoroethane (R134a) as well as for binary and ternary mixtures of these refrigerants. Three cubic equations of state GEOS3C, SRK (Soave � Redlich � Kwong) and PR (Peng � Robinson) were used. A wide comparison with literature experimental data was made. For the refrigerant mixtures, classical van der Waals mixing rules without interaction parameters were used. The GEOS3C equation, with three parameters estimated by matching several points on the saturation curve (vapor pressure and corresponding liquid volumes), compares favorably to other equations in literature, being simple enough for applications.

Self-Diffusion in Molten Lithium Nitrate

1992 ◽  
Vol 47 (10) ◽  
pp. 1047-1050 ◽  
Author(s):  
C. Herdlicka ◽  
J. Richter ◽  
M. D. Zeidler
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Spin Echo ◽  
The Self ◽  
Lithium Nitrate ◽  
Equimolar Ratio ◽  
Self Diffusion ◽  
Field Gradients ◽  
Molten Lithium ◽  
Self Diffusion Coefficient

AbstractSelf-diffusion coefficients of 7Li+ ions have been measured in molten LiNO3 with several compositions of 6Li+ and 7Li+ over a temperature range from 537 to 615 K. The NMR spin-echo method with pulsed field gradients was applied. It was found that the self-diffusion coefficient depends on the isotopic composition and shows a maximum at equimolar ratio. At temperatures above 600 K this behaviour disappears.

Zu Stofftransport und Hydrodynamik der Pulsationsdiffusion

1974 ◽  
Vol 29 (7) ◽  
pp. 1045-1049
Author(s):  
H. Beßerdich ◽  
E. Kahrig ◽  
Fr. Lange
Keyword(s):  
Diffusion Coefficients ◽  
Ternary Mixtures ◽  
Diffusion Method ◽  
Periodic Flow ◽  
Matter Transport ◽  
Binary And Ternary Mixtures ◽  
Transfer Parameters ◽  
Diffusion Separation ◽  
Separation Problems

The pulsation diffusion method is used successfully for the determination of diffusion coefficients in different systems (selfdiffusion, binary and ternary mixtures) and in connection with diffusion separation in liquids. The main advantage is the enhancement of matter transport by periodic flow e. g. in a capillary. Adapting a computation by P. L. Kapiza it is reported on a general treatment for the special conditions in a pulsation diffusion apparatus. Transport behavior depends strongly on hydrodynamic and mass transfer parameters. The results are important for the application of the pulsation method for measuring diffusion coefficients and for separation problems.

PFG-NMR Measurements of the Self-Diffusion Coefficients of Water in Equilibrium Poly(HEMA-co-THFMA) Hydrogels

2002 ◽  
Vol 3 (3) ◽  
pp. 554-559 ◽  
Author(s):  
Phuong Y. Ghi ◽  
David J. T. Hill ◽  
Andrew K. Whittaker
Keyword(s):  
Diffusion Coefficients ◽  
The Self ◽  
Self Diffusion ◽  
Pfg Nmr
Sign in / Sign up

Export Citation Format

Share Document