[A model of non-electrogenic cation transport through bilayer lipid membranes]

Quantitative relationship between the proton diffusion potential in the unstirred layers near BLM and NH4Cl was investigated. It has been found that in the range of low concentrations of NH4Cl the potential value depends on the difference of salt concentrations on different sides of the membrane. At higher concentrations the potential value is the function of the ratio of salt concentrations at different BLM sides. In the limiting case the potential value equals 58 mV with NH4Cl concentrations ratio equaling ten. A model is suggested which quantitatively describes the experimental data. It has been shown that the results obtained can be used in determining BLM permeability for weak acids and bases.