We present a phenomenological study of the bridging adsorption of flexible
chains during the non-inertial flow of polymer solutions in disordered poro
us media. Using simple physical arguments we have established the time depe
ndence of the concentration of the chains retained in a single pore due to
the bridging adsorption. We have then shown, in the limit of vanishing deso
rption, that the hydrodynamic resistance scales as a function of time accor
ding to an exponential law. (C) 2001 Academie des sciences/Editions scienti
fiques et medicales Elsevier SAS.