Ionic accumulation by water flow through a membrane.

Abstract

AbstractRapoport, S. I. Ionic accumulation by water flow through a membrane. Acta physiol. scand. 1965. 64. 361–371. – The relation between diffusion and water flow for solutions of KC1 and of KCl + LiCl, was studied in the absence of electric current on artificial, wide pore membranes which were effectively uncharged and nonselective. Ionic mobilities in the membrane were obtained from limiting ionic conductances in water. Diffusion coefficients for KCl in the membrane were obtained under zero and non‐zero flow conditions. They were used to compare predicted with observed steady state,“specific ionic” and“accumulation” ratios. Significant disagreement was found only between the diffusion coefficient derived from the observed accumulation ratios and the zero flow coefficient. Possible reasons were discussed. An accumulation ratio of 6.9, for K+ to Li+, was obtained. In the non‐steady state, the flux of KCI, when the sole solute, could be represented by a proposed equation (Eq. 4). With KCl + LiCl, the net cationic flux ratio could also be predicted (Eq. 8). At the steady state, the system represented a first order state, in which the force acting on water was constant and in which a transport mechanism, which was not ion specific, existed.