Eur. Phys. J. E 3, 389-394
Time evolution of near membrane layers
K. Dworecki1 -
T. Koszto
owicz1 -
St. Mrówczynski1,2
- S. Wasik1
1 Institute of Physics, Pedagogical University,
ul. Konopnickiej 15, PL 25-406 Kielce, Poland
2 Sotan Institute for Nuclear Studies,
ul. Hoza 69, PL 00-681 Warsaw, Poland
dworecki@pu.kielce.pl
tkoszt@pu.kielce.pl
mrow@fuw.edu.pl
Received 12 November 1999 and Received in final form 3 July 2000
Abstract
The near membrane layer is a region where the concentration
of the substance transported across the membrane is significantly
decreased. Its thickness is defined as a length over which the
concentration drops k times with k being an arbitrary large number.
The time evolution of such a layer is studied experimentally by means
of the laser interferometric method. It is shown that within the
experimental errors the thickness of the near membrane layer grows in
time for any k as 
with the coefficient a being independent
of the initial concentration and the membrane permeability. Time evolution
of the near membrane layers is also analyzed theoretically. The regularities
found experimentally are naturally described within the model which has
been earlier developed by one of us. In particular, a scales as
.
PACS
66.10.Cb Diffusion and thermal diffusion -
82.65.Fr Film and membrane processes: ion exchange, dialysis, osmosis, electroosmosis
Copyright EDP Sciences, Società Italiana di Fisica, Springer-Verlag
