Random porous media

VII. POLYMER CHAINS IN RANDOM POROUS MEDIA A. Scaling Laws in Equilibrium... 

MC simulations and semianalytical theories for diffusion of flexible polymers in random porous media, which have been summarized [35], indicate that the diffusion coefficient in random three-dimensional media follows the Rouse behavior (D N dependence) at short times, and approaches the reptation limit (D dependence) for long times. By contrast, the diffusion coefficient follows the reptation limit for a highly ordered media made from infinitely long rectangular rods connected at right angles in three-dimensional space (Uke a 3D grid). 

Description of Random Porous Media and the Method of Stochastic Two-scale Convergence in the Mean... 

Natural and man-made porous media usually possess formidably complex microstructure, often hierarchical. In this paper we shall not discuss hierarchical microstructures revealed, for instance by fractured porous media and biological tissues like bone and soft tissue. However, recently developed stochastic reiterated homogenisation enables one to determine macroscopic properties of random porous media with hierarchical architecture, cf. [11],... 

Telega, J.J. and Bielski, w. (2003) Flow in Random Porous Media Effective Models. Comp. Geo tech. 30, 271-288... 

The tortuosity term is intended to account for increases in diffusional path length due to windiness. Classical descriptions of the tortuosity predict a value of 1 to 3 for random porous media (.2.). Since the tortuosities inferred by these models are orders of magnitude greater than expected, other physical properties of the system must be important in determining release rates. Since continuum diffusion models provide an incomplete description of the release from these devices, the microscopic details of the system must be considered explicitly. 

Baumgartner, A., and Muthukmnar, M. A trapped polymer chain in random porous media, J. Chem. Phys., 87, 3082, 1987. 

Pizio, O. (2000). Adsorption in random porous media. In Computational Methods in Surface and Colloid Science, Borowko, M. (ed.). Marcel Dekker, New York, pp. 292-346. 

After validation, the LPBM has been employed to simulate the electroosmotic flows in microgeometries. Besides the straight channel, complex geometries have also been considered, including a rough channel, porous arrays, and even random porous media. The simulation results are also compared with the existing experimental data. 

Though confinement of fluids within random porous media can lead to drastic changes in their physical properties which are not very well known, the observation of an exponential nuclear relaxation of the longitudinal or transverse magnetization... 

Telega, J.J. Bielski, W.R. (2003). Flows in random porous media effective models. Comp. 

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