title: Empirical time dependence of liquid self-diffusion coefficient in porous media.
abstract: A new method of finding experimental time dependence of the self-diffusion coefficient D(t) for fluid in the porous media is proposed. We investigate the time-dependent self-diffusion coefficient D(t) of random walkers in permeable porous media. D(t) is measured in pulse field gradient (PFG) experiments with fluid-saturated porous media of randomly packed spherical glass beads. In absence of the specific interactions between pore walls and a fluid we show that D(t) = (D(0) - D(∞))exp(-F√(D(0)t)/d) + D(∞), where D(0) is the diffusion constant in a bulk fluid, D(∞) is the asymptotical value of the diffusion coefficient for long diffusion times (t→∞), d is the bead diameter and F is the constant characterizing the geometry (the size and shape) pores.
authors.affiliation: Physics and Mathematics Department, Mary State University, Lenin sq., 1, Yoshkar-Ola 424000, Russia. val_losk@rambler.ru
authors.forename: V V
authors.initials: VV
authors.lastname: Loskutov
mesh_terms: D000465:Algorithms; D004058:Diffusion; D016521:Electrophoresis, Gel, Pulsed-Field; D005583:Fourier Analysis; D005898:Glass; D009682:Magnetic Resonance Spectroscopy; D008863:Microspheres; D016062:Porosity; D013997:Time Factors