Invariance of the point of inversion in binary isotonic osmosis

Abstract

Using binary isotonic osmosis in an ion exchanger membrane the inversion of the water flux has been observed. This effect was found to be dependent on the total outside concentration only, and is independent of the gradients of chemical potentials of the solute. The water flux vanishes when the concentrations of Donnan and fixed ions are equal, in accordance with the principle of minimal entropy production in systems under constraint.