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Biomedical subjects

F Conti

Publications and source records attributed to F Conti.

At least 307 records · Page 17Linked to original sources
PubMed1966

The steady-state properties of an ion exchange membrane with mobile sites.

A study of the properties of the steady states of a system composed of two solutions separated by an ion exchange membrane having mobile sites is presented. It is assumed that the membrane is impermeable to coions; the solutions contain no more than two species of counterions, both of the same valence; and no flow of bulk solution occurs. Assuming that all ions are completely dissociated, behave ideally, and have constant mobilities throughout the membrane, explicit expressions are derived for the steady states of the electric current, individual fluxes, and concentration profiles as functions of the compositions of the solutions and of the difference of electric potential between them. The derived expressions are compared with those for an ion exchange membrane having fixed sites; and it is found that the expressions of certain quantities, such as the difference of electric potential between the two solutions for zero current or the ratio of the fluxes of the counterions as functions of the external parameters of the system, are the same for both types of membranes. On the other hand, differences in the behavior of the two types of membranes are found from other expressions-for example, the current-voltage relationship. In the mobile site ion exchanger the current asymptotically approaches finite limiting values for high positive and negative voltages while in the fixed site ion exchanger it is the conductance which approaches finite limiting values.

Biological Transport↗
PubMed1965

The steady state properties of ion exchange membranes with fixed sites.

The properties of the steady states of a system composed of two solutions separated by a quite general type of ion exchange membrane having fixed sites are derived as functions of the compositions of the solutions and of the difference of electric potential between the two solutions. These properties are evaluated with the restraints that the membrane is solely permeable to cations or anions, no flow of solvent occurs, and the solutions contain no more than two permeant ionic species, which are monovalent. Under the assumptions that the difference of standard chemical potentials of the permeant species and the ratio of their mobilities are constant throughout the membrane, even when the spacing of sites is variable, explicit expressions are derived for the electric current, individual fluxes, and concentration profiles. An unexpectedly simple dependence of these expressions upon distribution of sites is found.

Chemical Phenomena↗