scholarly journals Unveiling Carbon Dioxide and Ethanol Diffusion in Carbonated Water-Ethanol Mixtures by Molecular Dynamics Simulations

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1711
Author(s):  
Mohamed Ahmed Khaireh ◽  
Marie Angot ◽  
Clara Cilindre ◽  
Gérard Liger-Belair ◽  
David A. Bonhommeau
Keyword(s):  
Carbon Dioxide ◽  
Molecular Dynamics ◽  
Diffusion Coefficients ◽  
Hydrodynamic Radius ◽  
Md Simulations ◽  
Molecular Models ◽  
Experimental Values ◽  
Carbon Dioxide Co2 ◽  
Dynamics Simulations ◽  
Apparent Disagreement

The diffusion of carbon dioxide (CO2) and ethanol (EtOH) is a fundamental transport process behind the formation and growth of CO2 bubbles in sparkling beverages and the release of organoleptic compounds at the liquid free surface. In the present study, CO2 and EtOH diffusion coefficients are computed from molecular dynamics (MD) simulations and compared with experimental values derived from the Stokes-Einstein (SE) relation on the basis of viscometry experiments and hydrodynamic radii deduced from former nuclear magnetic resonance (NMR) measurements. These diffusion coefficients steadily increase with temperature and decrease as the concentration of ethanol rises. The agreement between theory and experiment is suitable for CO2. Theoretical EtOH diffusion coefficients tend to overestimate slightly experimental values, although the agreement can be improved by changing the hydrodynamic radius used to evaluate experimental diffusion coefficients. This apparent disagreement should not rely on limitations of the MD simulations nor on the approximations made to evaluate theoretical diffusion coefficients. Improvement of the molecular models, as well as additional NMR measurements on sparkling beverages at several temperatures and ethanol concentrations, would help solve this issue.

Molecular Dynamics Simulations of Atoms Diffusion in Solid

2018 ◽  
Vol 15 ◽  
pp. 51-64
Author(s):  
Yu Lu Zhou ◽  
Xiao Ma Tao ◽  
Qing Hou ◽  
Yi Fang Ouyang
Keyword(s):  
Molecular Dynamics ◽  
Diffusion Coefficients ◽  
Md Simulations ◽  
Einstein Relation ◽  
Interatomic Potentials ◽  
Body System ◽  
Many Body ◽  
Point Particles ◽  
Bulk Surface ◽  
Dynamics Simulations

Molecular dynamics (MD) simulations, which treat atoms as point particles and trace their individual trajectories, are always employed to investigate the transport properties of a many-body system. The diffusion coefficients of atoms in solid can be obtained by the Einstein relation and the Green-Kubo relation. An overview of the MD simulations of atoms diffusion in the bulk, surface and grain boundary is provided. We also give an example of the diffusion of helium in tungsten to illustrate the procedure, as well as the importance of the choice of interatomic potentials. MD simulations can provide intuitive insights into the atomic mechanisms of diffusion.

Molecular dynamics simulation of multi-constituent gas diffusion properties in Venus atmosphere

2021 ◽  
Author(s):  
Wen Gao ◽  
Xiaoning Yang ◽  
Jing Wang ◽  
Quanwen Hou ◽  
Yanqiang Bi ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Diffusion Coefficients ◽  
Gas Diffusion ◽  
Dynamics Simulation ◽  
Diffusion Characteristics ◽  
Temperature And Pressure ◽  
Experimental Values ◽  
Dynamics Simulations ◽  
Interdiffusion Coefficients ◽  
Diffusion Properties

Abstract The purpose of studying the Venus’s atmosphere is to model and simulate Venus’s environment. One of the key parameters of the Venus’s atmosphere is diffusion coefficient. Experimental measurements of diffusion coefficients are particularly difficult under Venus’s environmental conditions. Molecular dynamics have become an important method for studying the properties and dynamics of microscopic systems. In this paper, the equilibrium molecular dynamics (EMD) simulations are used to calculate the interdiffusion coefficients of carbon dioxide (CO2) and nitrogen (N2) at room temperature and pressure in combination with Darken's equation. And the results are compared with experimental values and empirical equations to verify the rationality of the calculation method and the accuracy of the results. The interdiffusion coefficients of trace gases on the surface of Venus for the CO2 system in different states and the CO2-N2 interdiffusion coefficients with altitude in the Venus environment are given. The results show that the diffusion coefficients of the gases on the surface of Venus are two orders of magnitude smaller than those in the Earth's atmosphere and molecular dynamics simulations can well predict the diffusion characteristics of the Venus’s atmosphere and support the simulation of the Venus’s surface environment and the Venus’s atmosphere model.

scholarly journals Determination of Reference Chemical Potential Using Molecular Dynamics Simulations

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Krishnadeo Jatkar ◽  
Jae W. Lee ◽  
Sangyong Lee
Keyword(s):  
Molecular Dynamics ◽  
Gas Hydrates ◽  
Chemical Potential ◽  
Md Simulations ◽  
Water Molecules ◽  
Chemical Potential Difference ◽  
Guest Molecules ◽  
Experimental Values ◽  
Dynamics Simulations

A new method implementing molecular dynamics (MD) simulations for calculating the reference properties of simple gas hydrates has been proposed. The guest molecules affect interaction between adjacent water molecules distorting the hydrate lattice, which requires diverse values of reference properties for different gas hydrates. We performed simulations to validate the experimental data for determining , the chemical potential difference between water and theoretical empty cavity at the reference state, for structure II type gas hydrates. Simulations have also been used to observe the variation of the hydrate unit cell volume with temperature. All simulations were performed using TIP4P water molecules at the reference temperature and pressure conditions. The values were close to the experimental values obtained by the Lee-Holder model, considering lattice distortion.

Molecular dynamics simulations of some amorphous and crystalline photonic materials

1990 ◽  
Vol 5 (5) ◽  
pp. 1104-1109 ◽  
Author(s):  
Pradeep P. Phule ◽  
Pierre A. Deymier ◽  
Subhash H. Risbud
Keyword(s):  
Molecular Dynamics ◽  
Optical Switching ◽  
Bond Distance ◽  
Md Simulations ◽  
Dielectric Constants ◽  
Nonlinear Susceptibility ◽  
Naci Crystal ◽  
Doped Glasses ◽  
Experimental Values ◽  
Dynamics Simulations

Constant pressure molecular dynamics (MD) simulations have been used to simulate amorphous and crystalline forms of BaTiO3 and TiO2. Simulation results for pure RaTiO3 and TiO2 glasses show fourfold titanium coordination with a Ti–O bond distance of 1.8 Å, consistent with experimental evidence for the structure of titania doped glasses for all optical switching and ultra low expansivity (ULE) TiO2–SiO2 glasses. Radial distribution function data for crystalline, liquid, and amorphous forms of BaTiO3 were also obtained. The displacement polarization and its contribution to susceptibilities have been calculated by application of an electric field to the simulation cell. The calculated ionic dielectric constants (Ki) for simulated NaCI (crystal), TiO2 glass, and TiO2 (crystal) were 3.34, 5.96, and 19.4 as compared to the experimental values of ≍3.34, 3–10, and 78, respectively. The calculated cubic nonlinear susceptibility (ξ3) values for NaCI (crystal), TiO2 (glass), and TiO2 (crystal) were, respectively, 0.194, 2.175, and 4.68 (x 10−18m2V−2). The increase in ξ3 values is consistent with experimentally observed trends of the linear refractive indices. Improved agreement between experimental and calculated values of susceptibilities and dielectric constant was obtained for materials with higher ionicity.

Predicting Methane Diffusivity in Polymeric Membranes by Molecular Dynamics

2015 ◽  
Vol 1119 ◽  
pp. 461-465
Author(s):  
M.K. Hadj-Kali ◽  
A. Bessadok-Jemai ◽  
S. Haider ◽  
Y. Alzeghayer
Keyword(s):  
Molecular Dynamics ◽  
Small Molecules ◽  
Diffusion Coefficients ◽  
Md Simulations ◽  
Polymeric Membranes ◽  
Transport Mechanisms ◽  
Fluid Equation ◽  
Cell Modules ◽  
Dynamics Simulations ◽  
Materials Studio

Diffusion coefficients of methane (CH4) have been obtained by Molecular Dynamics (MD) simulations combined with Einstein fluid equation. Three polymers were considered, namely polyethylene, polypropylene and poly (cis-1,4-butadiene). All calculations were performed by means of Polymer Builder and Amorphous Cell modules within Materials Studio (Accelrys). The obtained diffusivity results are within the range of published results for similar small molecules. Molecular dynamics simulations proved to be a useful tool for understanding the detailed descriptions and transport mechanisms occurring within the material.

Lanthanoids(III) and actinoids(III) in water: Diffusion coefficients and hydration enthalpies from polarizable molecular dynamics simulations

2012 ◽  
Vol 85 (1) ◽  
pp. 237-246 ◽  
Author(s):  
Fausto Martelli ◽  
Sacha Abadie ◽  
Jean-Pierre Simonin ◽  
Rodolphe Vuilleumier ◽  
Riccardo Spezia
Keyword(s):  
Molecular Dynamics ◽  
Diffusion Coefficients ◽  
Heavy Ions ◽  
Md Simulations ◽  
Contradictory Result ◽  
Dielectric Friction ◽  
Water Interaction ◽  
Diffusive Regime ◽  
Dynamics Simulations ◽  
Good Agreement

By using polarizable molecular dynamics (MD) simulations of lanthanoid(III) and actinoid(III) ions in water, we obtained ionic diffusion coefficients and hydration enthalpies for both series. These values are in good agreement with experiments. Simulations thus allow us to relate them to microscopic structure. In particular, across the series the diffusion coefficients decrease, reflecting the increase of ion–water interaction. Hydration enthalpies also show that interactions increase from light to heavy ions in agreement with experiment. The apparent contradictory result of the decrease of the diffusion coefficient with decreasing ionic radius is tentatively explained in terms of dielectric friction predominance on Stokes’ diffusive regime.

Separation of carbon dioxide and nitrogen gases through modified boron nitride nanosheets as a membrane: insights from molecular dynamics simulations

RSC Advances ◽  
2016 ◽  
Vol 6 (97) ◽  
pp. 94911-94920 ◽  
Author(s):  
Jafar Azamat ◽  
Alireza Khataee ◽  
Fahreddin Sadikoglu
Keyword(s):  
Carbon Dioxide ◽  
Molecular Dynamics ◽  
Boron Nitride ◽  
Molecular Dynamics Simulations ◽  
High Selectivity ◽  
Md Simulations ◽  
Boron Nitride Nanosheets ◽  
Dynamics Simulations ◽  
Simulation Time

The progress of gas propagating through the pores of BNNSs was simulated using MD simulations. During a simulation time of 50 ns at 298 K, there is no CO2 propagating through, meaning a high selectivity of pore 4 for CO2/N2 separation.

Assessing the Antimalarial Potentials of Phytochemicals: Virtual Screening, Molecular Dynamics and In-Vitro Investigations

2019 ◽  
Vol 16 (3) ◽  
pp. 291-300
Author(s):  
Saumya K. Patel ◽  
Mohd Athar ◽  
Prakash C. Jha ◽  
Vijay M. Khedkar ◽  
Yogesh Jasrai ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Structural Integrity ◽  
Md Simulations ◽  
Tylophora Indica ◽  
Multidrug Resistance Protein 1 ◽  
Receptor Complexes ◽  
Resistance Protein ◽  
Dynamics Simulations ◽  
Stable Trajectory

Background: Combined in-silico and in-vitro approaches were adopted to investigate the antiplasmodial activity of Catharanthus roseus and Tylophora indica plant extracts as well as their isolated components (vinblastine, vincristine and tylophorine). </P><P> Methods: We employed molecular docking to prioritize phytochemicals from a library of 26 compounds against Plasmodium falciparum multidrug-resistance protein 1 (PfMDR1). Furthermore, Molecular Dynamics (MD) simulations were performed for a duration of 10 ns to estimate the dynamical structural integrity of ligand-receptor complexes. </P><P> Results: The retrieved bioactive compounds viz. tylophorine, vinblastin and vincristine were found to exhibit significant interacting behaviour; as validated by in-vitro studies on chloroquine sensitive (3D7) as well as chloroquine resistant (RKL9) strain. Moreover, they also displayed stable trajectory (RMSD, RMSF) and molecular properties with consistent interaction profile in molecular dynamics simulations. </P><P> Conclusion: We anticipate that the retrieved phytochemicals can serve as the potential hits and presented findings would be helpful for the designing of malarial therapeutics.

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