Molecular-dynamics investigation of tracer diffusion in a simple liquid

Ould-Kaddour, F.; Barrat, Jean‐Louis

doi:10.1103/physreva.45.2308

Cited by 34 publications

(30 citation statements)

References 14 publications

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“…We compare D W CA and D HS at temperature 1.663 with the classical Knudsen model (2). Although all three models predict the diffusive to be linear with r ph , (r ph = r pore − σ 22 2 ), D Knudsen shows slightly stronger r ph dependence whereas the r ph dependence of D W CA and D HS are similar in nature. The diffusion values for the WCA systems are a bit lower because the length-scale of the WCA potential is larger than the hard sphere (HS) potential making the pore narrower (2).…”

Section: Acs Paragon Plus Environmentmentioning

confidence: 91%

“…[9][10][11][12][13][14][15] The diffusion of small solute particle is also known to show a deviation from the SE relation. [16][17][18][19][20][21][22][23][24] Different 3 experimental, theoretical and computational simulation studies attribute this deviation to apparently different phenomena. In some cases an empirical modification of the SE relation, assuming a fractional viscosity dependence, is used to explain the deviation.…”

Section: Introductionmentioning

confidence: 88%

“…The calculations were done for a fixed size of the nanopore, r pore and varying the size of the diffusing particle, σ 22 . We compare D W CA and D HS at temperature 1.663 with the classical Knudsen model (2).…”

Section: Acs Paragon Plus Environmentmentioning

confidence: 99%

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Diffusion of Small Solute Particles in Viscous Liquids: Cage Diffusion, a Result of Decoupling of Solute–Solvent Dynamics, Leads to Amplification of Solute Diffusion

et al. 2015

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We study the diffusion of small solute particles through solvent by keeping the solute-solvent interaction repulsive and varying the solvent properties. The study involves computer simulations, development of a new model to describe diffusion of small solutes in a solvent, and also mode coupling theory (MCT) calculations. In a viscous solvent, a small solute diffuses via coupling to the solvent hydrodynamic modes and also through the transient cages formed by the solvent. The model developed can estimate the independent contributions from these two different channels of diffusion. Although the solute diffusion in all the systems shows an amplification, the degree of it increases with solvent viscosity. The model correctly predicts that when the solvent viscosity is high, the solute primarily diffuses by exploiting the solvent cages. In such a scenario the MCT diffusion performed for a static solvent provides a correct estimation of the cage diffusion.

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Section: Acs Paragon Plus Environmentmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 88%

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Diffusion of Small Solute Particles in Viscous Liquids: Cage Diffusion, a Result of Decoupling of Solute–Solvent Dynamics, Leads to Amplification of Solute Diffusion

et al. 2015

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“…Electronic mail: tcc.chan@polyu.edu.hk found in computer simulations and theoretical studies. [4][5][6][7] Although many modified SE relations have been developed, it appears insofar that none could satisfactorily account for a broad range of diffusivities. The SE relation and its modifications have been reviewed by Cussler 8 and Reid et al 9 The other major approach in diffusion study is Enskog's kinetic theory, which takes binary collisions of molecules into account.…”

Section: Introductionmentioning

confidence: 99%

Diffusion of aromatic compounds in nonaqueous solvents: A study of solute, solvent, and temperature dependences

Chan

Tang

2013

The Journal of Chemical Physics

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Tracer diffusivities (limiting mutual diffusion coefficients) of nonassociated aromatic compounds in n-hexane and cyclohexane have been measured at 298.2 K by Taylor's dispersion method. These new data, together with other diffusivities of nonassociated pseudoplanar solutes reported in the literature, are used to determine the separate effects of solute and solvent on tracer diffusion. The data show that for a given pseudoplanar solute diffusing in different solvents at 298.2 K, the tracer diffusivity is dependent not only on the fractional viscosity of the solvent but also on a function of the solvent's molar density, molecular mass, and free volume fraction. For different pseudoplanar aromatic solutes diffusing in a particular solvent at a constant temperature, there is a linear relationship between the reciprocal of the tracer diffusivity and the molecular volume of the solutes. The results are discussed in respect to relevant theories and experimental studies in the literature. An idealized relation, developed on the basis of the Einstein equation by incorporating the newly found solute and solvent dependences, is capable of describing a total of 176 diffusivities of nonassociated pseudoplanar solutes in various solvents at different temperatures to within an average error of ±2.8%. © 2013 AIP Publishing LLC. [http://dx

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“…A similar expression called the DebyeStokes-Einstein relation is also obtained between the rotational diffusion and the viscosity. Although in hydrodynamics the validity of the Stokes-Einstein relation is independent of the size of the solute, experimental studies [3,4] and simulations [5] have found that for small solutes, the SE relation underestimates the value of the diffusion. The enhanced diffusion is often explained in terms of (i) fractional viscosity dependence of the diffusion [3], (ii) an effective hydrodynamic radius which depends on the solute-solvent size ratio [6], (iii) decoupling of the solute dynamics from the solvent density fluctuation [7].…”

Section: Introductionmentioning

confidence: 99%

A mode coupling theory analysis of microscopic friction in the macroscopic limit

Bhattacharyya

2004

Chemical Physics Letters

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Molecular-dynamics investigation of tracer diffusion in a simple liquid

Cited by 34 publications

References 14 publications

Diffusion of Small Solute Particles in Viscous Liquids: Cage Diffusion, a Result of Decoupling of Solute–Solvent Dynamics, Leads to Amplification of Solute Diffusion

Diffusion of Small Solute Particles in Viscous Liquids: Cage Diffusion, a Result of Decoupling of Solute–Solvent Dynamics, Leads to Amplification of Solute Diffusion

Diffusion of aromatic compounds in nonaqueous solvents: A study of solute, solvent, and temperature dependences

A mode coupling theory analysis of microscopic friction in the macroscopic limit

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