A note on permeation with boundary-layer resistance

An analytical solution is given to the problem of transport through a slab membrane in the presence of two simple boundary-layer resistances and expli cit expressions derived for the time-lags associated with the permeation. T he treatment relates to a constant diffusion coefficient. Calculated values of the outgoing 'adsorption' time-lag differ markedly from those obtained by Skaarup and Hansen [Polym. Eng. Sci. 20 (1980) 259] using a numerical pr ocedure. Use of four time-lags allows the solubility/adsorption isotherm to be determined. (C) 2001 Elsevier Science B.V. All rights reserved.