## Abstract

The effective diffusion coefficient D_{e} for porous media composed of identical obstacles of radius R in which the diffusing particles have finite radius βR (β≥0) is determined by an efficient Brownian motion simulation technique. This is accomplished by first computing D_{e} for diffusion of "point" Brownian particles in a certain system of interpenetrable spherical obstacles and then employing an isomorphism between D_{e} for this interpenetrable sphere system and D_{e} for the system of interest, i.e., the one in which the Brownian particles have radius βR. [S. Torquato, J. Chem. Phys. 95, 2838 ( 1991 )]. The diffusion coefficient is computed for the cases β = 1/9 and β = 1/4 for a wide range of porosities and compared to previous calculations for point Brownian particles (β = 0). The effect of increasing the size of the Brownian particle is to hinder the diffusion, especially at low porosities. A simple scaling relation enables one to compute the effective diffusion coefficient D_{e} for finite β given the result of D_{e} for β = 0.

Original language | English (US) |
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Pages (from-to) | 1498-1503 |

Number of pages | 6 |

Journal | The Journal of chemical physics |

Volume | 96 |

Issue number | 2 |

DOIs | |

State | Published - 1992 |

Externally published | Yes |

## All Science Journal Classification (ASJC) codes

- General Physics and Astronomy
- Physical and Theoretical Chemistry