V. Aguilella et al., ION-TRANSPORT THROUGH MEMBRANES WITH SOFT INTERFACES - THE INFLUENCE OF THE POLAR ZONE THICKNESS, Thin solid films, 272(1), 1996, pp. 10-14
A membrane with soft permeable interfaces in an aqueous solution has b
een modelled by taking into account the spatial distribution of struct
ural electric charges and dipoles in the interfaces. The model was dev
eloped with special stress on its application to biological membranes.
The electric potential distribution and the ion transport across the
membrane are studied and the important role of the interface thickness
L on ion transport and membrane selectivity is shown. An interesting
result is found for certain combinations of charge and dipole densitie
s: a cation selective membrane may become anion selective when L chang
es. It is discussed how the results obtained can help to explain exper
imental results for membrane selectivity.