Self-Diffusion in Gases and Liquids

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• 作者：Eli Ruckenstein and and Hongqin Liu
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：1997
• 出版时间：September 1997
• 年：1997
• 卷：36
• 期：9
• 页码：3927 - 3936
• 全文大小：267K
• 年卷期：v.36,no.9(September 1997)
• ISSN：1520-5045

文摘

A systematic study of the self-diffusion coefficient inhard-sphere fluids, Lennard-Jones fluids,and real compounds over the entire range of gaseous and liquid statesis presented. First anequation is proposed for the self-diffusion coefficient in ahard-sphere fluid based on the moleculardynamics simulations of Alder et al. (J. Chem. Phys.1970, 53, 3813) and Erpenbeck andWood(Phys. Rev. A 1991, 43, 4254).That expression, extended to the Lennard-Jones fluidsthroughthe effective hard-sphere diameter method, represents accurately theself-diffusion coefficientsobtained in the literature by molecular dynamics simulations, as wellas those determinedexperimentally for argon, methane, and carbon dioxide. A roughLennard-Jones expression,which contains besides the diameter _LJ and energy_LJ the translational-rotational factor,A_D(which could be correlated with the acentric factor), is adopted todescribe the self-diffusion innonspherical fluids. The energy parameter is estimated using acorrelation obtained fromviscosity data, and the molecular diameter is obtained from thediffusion data themselves. Theequation represents the self-diffusion coefficients with an averageabsolute deviation of 7.33%,for 26 compounds (1822 data points) over wide ranges of temperature andpressure.