DIFFUSIVE TRANSPORT ACROSS AN INTERFACE

Citation
Av. Barzykin et M. Tachiya, DIFFUSIVE TRANSPORT ACROSS AN INTERFACE, JOURNAL OF PHYSICAL CHEMISTRY B, 102(17), 1998, pp. 3192-3197
Citations number
5
Categorie Soggetti
Chemistry Physical
Journal title
JOURNAL OF PHYSICAL CHEMISTRY B
ISSN journal
15206106 → ACNP
Volume
102
Issue
17
Year of publication
1998
Pages
3192 - 3197
Database
ISI
SICI code
1089-5647(1998)102:17<3192:DTAAI>2.0.ZU;2-I
Abstract
The kinetics of material diffusion across an interface is analyzed wit h special emphasis on the effect of the interface permeability on the transport characteristics, such as the mean-square displacement and th e residence probability in each of the two phases separated by the int erface. Two practically important cases are considered, namely, one-di mensional diffusion in a stepwise potential and three-dimensional diff usion under a spherically symmetric square-well potential. The transpo rt characteristics are shown to be independent of the permeability at asymptotically long times, unless the interface is absolutely impermea ble. However, the way the asymptotic behavior is approached can be con trolled by the interface permeability. At low permeability values, the kinetics exhibit a characteristic intermediate stage that can last fo r such a long time that the true asymptotic behavior may not be observ ed experimentally at all. Along with exact analytical solutions of the diffusion problems at hand, useful approximate expressions are presen ted for different stages of the kinetics.